Researchers from the Professorship of Optics and Photonics of Condensed Matter (led by Prof. Dr. Carsten Deibel) at the Chemnitz University of Technology and several partner institutions have systematically investigated how organic solar cells behave when the usual donor–acceptor mixing ratio is pushed to the extreme – down to only 1 percent donor content. Using the well‑known PM6:Y12 material system, they link nanomorphology, charge transport, and recombination to device performance and provide a unified physical picture of “donor‑diluted” organic solar cells. This is taking place within the framework of the Research Unit "Printed & Stable Organic Photovoltaics with Non-Fullerene Acceptors - POPULAR", funded by the German Research Foundation, of which Prof. Deibel is the spokesperson.

Organic solar cells typically consist of two components: a donor, which tends to donate electrons, and an acceptor, which accepts electrons. When light is absorbed, electron–hole pairs are formed and then separated at the donor–acceptor interface, enabling the generation of photocurrent. “In recent years, dilute donor blends have reached surprisingly high efficiencies, but we lacked a consistent understanding of how morphology, transport, and recombination interplay in these systems,” says Prof. Dr. Carsten Deibel, head of the Chair of Optics and Photonics of Condensed Matter at Chemnitz University of Technology and corresponding author of the study. “Our work shows that donor dilution mainly reshapes the topology of the transport network – and that this topology, rather than a sharp percolation threshold, defines the performance limits.”

Continuous donor network even at low content

In their study, the team fabricated PM6:Y12 bulk‑heterojunction solar cells with donor fractions ranging from 1 to 45 percent and characterized them with a broad set of structural, optical, and electrical methods. Grazing‑incidence wide‑angle X‑ray scattering (GIWAXS) and resonant soft X‑ray scattering (RSoXS) reveal that even below 5 percent donor content, lamellar stacking enables charge extraction in the inverted device architecture used. Complementary ultraviolet photoelectron spectroscopy (UPS) depth profiling confirms that, apart from a thin donor-rich surface layer, the bulk composition closely follows the nominal donor–acceptor ratio across all blends.

To quantify charge transport, the researchers extract an effective active‑layer conductivity directly from current–voltage curves under illumination, based on a recently developed method that separates recombination and transport contributions near open‑circuit voltage. The resulting effective conductivity, that accounts for electron and hole conductivities, drops strongly towards low donor content but shows a robust, nearly temperature‑independent scaling with composition when evaluated at a fixed energetic depth in the density of states. The authors show that this dependence can be described by a classical three‑dimensional percolation model. “We find that the topology of the PM6 transport network controls conductivity and mobility, and that this network behaves like a three‑dimensional percolating system without a pronounced percolation threshold,” says Dr. Maria Saladina, co‑lead author of the study.

Exciton quenching experiments indicate nearly complete harvesting of PM6 excitons for all compositions, while the quenching of Y12 excitons and their effective lifetime improve with increasing donor content. “Even at very low donor fractions, we still observe a continuous, three‑dimensional PM6 network rather than isolated donor islands,” explains first author Dr. Chen Wang. This connectivity is crucial to maintain efficient charge extraction despite strong dilution.

From reduced Langevin to Smoluchowski‑type recombination

Nongeminate recombination is analysed by combining time‑resolved photoluminescence under 1‑sun‑equivalent excitation with time‑delayed collection field measurements. For higher donor fractions, the recombination kinetics can be described within a Langevin‑type framework with a pronounced Langevin reduction factor smaller than one, which the authors attribute mainly to redissociation of electron–hole pairs at the donor–acceptor interface before recombination.

At donor fractions below 5 percent, however, the situation changes qualitatively. The apparent recombination order and the time dependence of the recombination rate deviate from Langevin expectations, and the effective Langevin reduction factor extracted from experimental data can even exceed unity, i.e. the recombination rate becomes higher than predicted by the classical Langevin model. By analysing the long‑time dynamics, the authors identify a transition to a dispersive, Smoluchowski‑type recombination regime, where encounters of spatially distributed carriers lead to a characteristic power-law decay of the recombination rate. “In strongly diluted blends, charge carriers move in a topology‑limited network with spatially inhomogeneous fields, and the recombination kinetics become dispersive and scale‑free,” explains Saladina. “This Smoluchowski‑type regime goes beyond the conventional Langevin picture and helps explain why recombination can exceed Langevin predictions at very low donor contents.”

Publication in the Journal "Advanced Materials"

The study “Rethinking charge transport and recombination in donor‑diluted organic solar cells” appears as a research article in the renowned journal Advanced Materials. The work was led by Maria Saladina together with Carsten Deibel at the Institute of Physics, Chemnitz University of Technology, in collaboration with researchers from the University of Freiburg, Fraunhofer ISE, the University of Bayreuth, TU Dresden, IFW Dresden, and Durham University. The research builds on and extends earlier work by the Chemnitz group showing that transport resistance dominates fill‑factor losses in record organic solar cells and provides a quantitative framework to describe these losses via an effective conductivity and a transport‑related figure of merit. These results have been achieved within the framework of the DFG Research Unit POPULAR, which continues to work on understanding and improving printed organic solar cells.

Background: DFG Research Group "Printed & Stable Organic Photovoltaics with Non-Fullerene Acceptors - POPULAR" under the leadership of TU Chemnitz

The research group "Printed & Stable Organic Photovoltaics with Non-Fullerene Acceptors - POPULAR" (FOR 5387), funded by the German Research Foundation with around five million euros, is leading in the field of optoelectronic characterization of organic solar cells. Prof. Dr. Carsten Deibel, holder of the Professorship of Optics and Photonics of Condensed Matter at TU Chemnitz, is the spokesperson for the DFG Research Unit, which involves 14 scientists from several universities in Germany and the UK. The common goal is to produce organic solar cells using mass-production-compatible printing processes and to understand and improve them with complementary experiments and simulations.

Publication: Chen Wang, Maria Saladina, Carsten Deibel, et al: Rethinking charge transport: Donor dilution reshapes limits of organic solar cells. Advanced Materials e23681 (2026). DOI: https://doi.org/10.1002/aenm.202405889

For further information, please contact Maria Saladina, phone +49 (0)371 531-34046, email maria.saladina@physik.tu-chemnitz.de, and Prof. Dr. Carsten Deibel, phone +49 (0)371 531-34878, email deibel@physik.tu-chemnitz.de.

(Source: Professorship of Optics and Photonics of Condensed Matter)

Only 20 projects nationwide were selected by the German Academic Exchange Service (DAAD) in the competitive "Academic Horizons" programme and Chemnitz University of Technology is among the winners, as the only higher education institution in Saxony to secure funding in this call. With a budget of 750,000 euros over 3.5 years, the project "AI GlobalMinds – Global Minds Advancing Next-Generation Sustainable AI for Innovation Leadership" stood out through its comprehensive integration concept, holistic AI education approach across the complete value chain, effective mobilization of existing DAAD partnerships and international networks, and strategic diversification of recruitment channels for Master's students and PhD candidates.

Running from May 2026 to December 2029, AI GlobalMinds addresses a critical challenge: Germany's growing shortage of qualified specialists in artificial intelligence. The project aims to diversify the recruiting channels for students and PhD candidates by creating structured international talent pathways, combining targeted recruitment from Chile, Tunisia and Serbia, and with academic qualification and practical integration into the German innovation ecosystem. TU Chemnitz will build new recruiting channels and advertising strategies to showcase its excellent education programs around AI from data acquisition and sensor technology, through AI methods and neuromorphic computing, to sustainable and Green AI applications in science and different economic sectors.

"AI GlobalMinds addresses a key challenge for Germany's innovation system," explains Prof. Dr. Olfa Kanoun, project coordinator at the Chair of Measurement and Sensor Technology. "The demand for AI expertise is growing rapidly, while qualified professionals remain scarce. By connecting international recruitment with structured qualification and integration, we create opportunities for both AI talents and Germany's innovation landscape."

From Sensors to Intelligent Systems: Comprehensive AI Education

What distinguishes AI GlobalMinds is its holistic approach to AI education. Rather than focusing on isolated algorithms, participants gain system-level understanding across the full AI value chain from sensor-based data acquisition to intelligent processing and real-world implementation in neuromorphic systems and robotics, with particular emphasis on sustainable and Green AI approaches.

“Neurorobotics represents the convergence of brain-inspired computing, embodied AI, and intelligent sensor systems,” explains Florian Röhrbein. “By bringing together international talent with diverse backgrounds in these complementary fields, we are building the interdisciplinary teams needed to advance intelligent systems that can truly interact with and learn from their environment — while also addressing energy efficiency and sustainability aspects that are crucial for the future of AI.”

The project brings together multiple faculties at TU Chemnitz: Electrical Engineering and Information Technology, Computer Science, and Mathematics alongside central institutions including the International University Center and Career Service.

Comprehensive Support: From Arrival to Career

"Successful international recruitment requires more than academic excellence it demands comprehensive support throughout the entire journey," emphasizes Katharina Wohlgemuth from the International University Center. "AI GlobalMinds provides exactly this: structured pre-arrival preparation, coordinated onboarding, buddy program, accelerated German language training, and continuous mentoring to ensure participants thrive both academically and socially in Chemnitz."

The project explicitly prepares participants for both academic and industry careers in Germany. "Germany's AI ecosystem needs qualified professionals across all sectorsfrom university research groups to innovative companies and applied research institutions," adds André Zwingenberger Claren from the Career Service. "Through targeted skills workshops, networking events with AI experts and industry representatives, and intercultural workplace training, we prepare AI GlobalMinds participants not just technically, but also for the realities and expectations of the German professional environment."

Building on established partnerships with universities in Tunisia, Serbia, and Chile, the project creates sustainable recruitment structures while strengthening international cooperation and diversifying TU Chemnitz's talent pipelines.

Background: Project "AI GlobalMinds"

AI development demands more than algorithms, it requires integrating data acquisition, hardware, and realworld implementation. AI GlobalMinds spans this full spectrum: from sensor technology through machine learning to sustainable Green AI applications. The project combines short-term orientation formats with longer study and research stays, allowing early identification of talent and gradual integration into academic and professional pathways in Germany. Students are introduced to research environments, work on practical topics, and gain experience in applying AI methods in realistic scenarios—from intelligent sensor systems to neuromorphic computing and autonomous robotics, with emphasis on energy-efficient and sustainable implementations.

At the same time, AI GlobalMinds strengthens existing international partnerships and contributes to the development of sustainable structures for recruiting and qualifying talent. By diversifying recruitment channels and building new pathways for international students and PhD candidates, the project supports Germany's long-term goals in innovation and artificial intelligence development.

Further Information: Prof. Dr. Olfa Kanoun, phone +49 (0)371 531-36931, email olfa.kanoun@etit.tu-chemnitz.de

(Author: Prof. Dr. Olfa Kanoun)

A Franco-German research team of members of the FEMTO-ST Institute at the Université Marie et Louis Pasteur, Besançon, as well as the Faculties of Electrical Engineering and Information Technology and Natural Sciences, and the Research Center for Materials, Architectures and Integration of Nanomembranes (MAIN) at Chemnitz University of Technology, have uncovered new insights into the formation of forbidden frequency bands in periodic solid-state structures. The study, titled “Contact points open wide band gaps in all two-dimensional Bravais lattices,” was published in late April in the physics journal Physical Review B and makes fundamental contributions to the understanding of the electromagnetic wave transport properties through regularly arranged materials.

This study examines the influence of contact points between copper tubes as individual scatterers arranged regularly in space on the propagation of radio waves and, consequently, on the formation of forbidden frequency regions for these waves—so-called band gaps. Using theoretical considerations, numerical simulations, and experimental measurements of scattering across all possible two-dimensional arrangements—known as Bravais lattices—of the tubes, the researchers demonstrate that contact points systematically generate wider band gaps, thereby enabling broadband filters for radio-frequency waves.

The results underscore that a precise understanding of the geometric structure of the scatterers and their exact positioning relative to one another, especially in the case of touch, can systematically influence and control the band structures, thereby helping to control and tailor the propagation of waves. Large, adjustable band gaps are of crucial importance, particularly for applications in electronics and photonics, as they determine the electrical and optical behavior of the components.

This study is part of the current research on the development of geometric effects in functional, two-dimensional membrane materials and is consistent with findings from previous research in which the authors demonstrated a similar effect for sound. It is inspired by work conducted as part of the TUCculture initiative on the stele artwork “Model of Thought and Perception for the Phenomenon of Color” by Dresden-based artist Stefan Nestler (1998), located in front of the Central Lecture Hall and Seminar Building at Chemnitz University of Technology. This artwork has been discovered as the world’s largest realization of a photonic crystal. By further developing this field, the authors are now making a positive contribution to basic research in the field of wave physics and providing a new impetus for materials research.

Original publication: D. Röhlig, R. Zichner, T. Blaudeck, A. Thränhardt, V. Laude: „Contact points open wide band gaps in all two-dimensional Bravais lattices“, Physical Review B 113, 144391 (2026). URL https://doi.org/10.1103/9ql7-t9rh

(Author: Dr. Thomas Blaudeck)

At the 23rd International Multi-Conference on Systems, Signals and Devices (SSD’26), held March 30 to April 2, 2026, in Catania, Italy, Dr. Ahmed Yahia Kallel, research associate and group leader for Impedance Spectroscopy and Measurement Systems at the Chair of Measurement and Sensor Technology (headed by Prof. Dr. Olfa Kanoun) at Chemnitz University of Technology, received the Best Paper Award.

Lithium-ion batteries are the backbone of electric mobility and stationary energy storage. To reliably determine their state of charge, researchers use Electrochemical Impedance Spectroscopy (EIS), a method that measures a battery’s electrical behavior across different frequencies and generates up to 480 data points per measurement – far too many for the small microcontrollers in battery management systems to process in real time. The award-winning paper “Fast A*-mRMR for Model-Aware Feature Selection in EIS-Based Battery State of Charge Estimation” addresses this challenge through intelligent pre-selection of the most informative data points. The method transfers the A* algorithm – a proven tool in robotics and game development for efficiently finding optimal paths through complex environments – to the domain of feature selection. Rather than exhaustively testing every possible feature combination, the algorithm identifies the best selection directly and efficiently, much like a navigation system finds the shortest route without driving down every road. Two criteria are considered simultaneously: how informative a data point is for predicting the state of charge, and how much it overlaps with already-selected points (Minimum Redundancy Maximum Relevance, mRMR).

Tested on physics-based digital twin data from four battery cells across 17 state-of-charge levels and three temperatures (756 measurement points in total), Fast A*-mRMR achieves a prediction accuracy of 3.62 to 3.93 % error with a computation time of just 1.27 seconds – more than 500 times faster than comparable methods while matching or exceeding their accuracy. The work also yields a counterintuitive insight: allowing a controlled degree of similarity between selected data points can actually improve predictions, contrary to the prevailing assumption that redundancy should always be minimized. “Our method enables the practical use of high-dimensional impedance data in resource-constrained embedded systems, laying an important foundation for more efficient and reliable battery management systems,” explains Dr. Ahmed Yahia Kallel. “The Best Paper Award is a gratifying recognition that our work in intelligent sensor systems and sustainable energy technologies is resonating with the international research community,” adds Prof. Dr. Olfa Kanoun.

The SSD is an established IEEE international multi-conference founded in 2001, bringing together research in the fields of systems, signal processing, and devices, with an H-index of 35. The award was presented at the sub-conference Power Systems & Smart Energies (PSE). The proceedings are published in IEEEXplore and indexed in Scopus and Web of Science.

Contact: Prof. Dr. Olfa Kanoun, Chair of Measurement and Sensor Technology, email olfa.kanoun@etit.tu-chemnitz.de

Citation: Kallel, A.Y., Kanoun, O.: “Fast A*-mRMR for Model-Aware Feature Selection in EIS-Based Battery State of Charge Estimation.” Proc. 23rd Int. Multi-Conf. on Systems, Signals and Devices (SSD’26), Catania, Italy, 2026. Best Paper Award.

(Author: Prof. Dr. Olfa Kanoun)

The University Library of Chemnitz University of Technology was awarded with the current “Open Library Badge” (OLB). It is the first library in Germany, which was honored with this award for the third time in succession. Already in 2016 and 2020, its successful implementation of openness principles was certified by the dedication of the OLB. “We are very proud to be awarded again. This award encourages us in our engagement to fulfill also further criteria and fields of action”, Dr. Wolfgang Lambrecht, Deputy Library Director, comments. The jury attested the University Library a consequent implementation of openness and transparency in its all-day Library life. It stated that the engagement is particularly strong in the topics “Participation and Citizen Science”, “Open Access” and “Open Data”.

During the Capital of Culture-year of Chemnitz 2025, the University Library performed a particularly high number of activities jointly with regional networks. Based on that, the collaboration between science and citizens shall be further enhanced by transparency and participation. The University Library offers in addition to the proven support of Open Access publishing also a comprehensive range of offers in the fields of Open Data and Open Educational Resources. In order to assure sustainable implementation, Open Science is included in varied ways in the strategy document of the University Library for developing towards a 5D-Library until the year 2030 (mytuc.org/jwvr). 

Keyword: Open Library Badge 2025

The “Open Library Badge 2025” includes seven topics in total: “Participation and Citizen Science”, “Inclusion and Social Commitment”, “Open Access”, “Open Data”, “Open Source”, “Open Educational Resources” as well as “Open Government and Open Research Information”. The respectively four fields of action are “Consulting and Teaching”, “Provision of infrastructure”, “Corporate Action and Implementation of Strategies” as well as “Cooperation and Engagement in Networks”.

More information regarding the „Open Library Badge“: http://badge.openbiblio.eu

Contact to the Open-Access-Team of Chemnitz University Library: Ute Blumtritt, phone: 0371 531-31290, email os@bibliothek.tu-chemnitz.de

(Translation: Dr. Wolfgang Lambrecht)

The question of "What binds the world in its innermost core?" was on Johann Wolfgang von Goethe's mind in "Faust." Many researchers at Chemnitz University of Technology also search for answers to this question. At the new Transmission Electron Microscopy Center (TEM-Center), officially opened on April 14^th, 2026, at Erfenschlager Straße 73 in Chemnitz, researchers aim to visualize structures smaller than the wavelength of visible light. This will enable them to identify atoms, molecules, and the bonds of matter. To achieve this, they will utilize the top-tier research infrastructure.

High-resolution microscopes enable precise material analysis

"The core of the new, single-story building are two highly sensitive transmission electron microscopes that allow us to examine the structure and properties of materials at the molecular and atomic levels, and then translate these findings to new applications," says Prof. Dr. Andreas Undisz, the Chair of Electron Microscopy and Microstructural Analysis at Chemnitz University of Technology and head of the new center. For example, processes that lead to material damage can be examined in very detail, enabling more accurate conclusions to be made about the durability and performance of components.

A worthwhile investment at Chemnitz University of Technology

"With this new building and the two electron microscopes, Chemnitz University of Technology is once again at the forefront of global materials research. The complex technical features offered by this facility as a whole can be found at only a few other locations worldwide. In addition to the three faculties, partner institutions will also benefit. This makes Chemnitz University of Technology even more attractive to top researchers from around the world. Thus, we strengthen the entire scientific region of Southwest Saxony,” said Saxony’s Minister of Science, Sebastian Gemkow, in a statement from the State Ministry of Finance.

"We at Chemnitz University of Technology are delighted to celebrate the opening of the Transmission Electron Microscopy Center. This is an important investment in Chemnitz University of Technology and, by extension, in Chemnitz as a research hub, in our core competencies in materials science and intelligent systems, and in our university’s national and international reputation. We are very grateful to the Free State of Saxony and to everyone involved who actively supported the establishment of the center," says Prof. Dr. Gerd Strohmeier, President at Chemnitz University of Technology. Prof. Dr. Anja Strobel, Deputy President and Vice President for Research and University Development at Chemnitz University of Technology, who represented the Rector in receiving the key, added: "The new Transmission Electron Microscopy Center, which brings together expertise from various research areas at Chemnitz University of Technology, significantly strengthens our university’s STEM field in research and teaching and creates highly attractive conditions for new interdisciplinary research projects as well as for recruiting and training our next generation of academics by providing researchers and students with access to the latest technologies and methods in materials science."

Technological marvels explore the nano cosmos

The electron microscopes, which tower over four meters, capture images of the tiniest structures at the nanometer level. "To ensure these sensitive marvels of technology can operate optimally, they are housed in specially shielded, climate-controlled rooms and rest on a 1.4-meter-thick vibration-damping concrete slab," explains Undisz. This keeps mechanical, acoustic, electromagnetic, and thermal sources of interference at a distance. Experiments using the large-scale research equipment in the protected inner core of the building are conducted remotely from operating rooms. In-depth material analysis using the two transmission electron microscopes requires preparing material samples just a few nanometers thin. This process is semi-automated in an adjacent room using a focused ion beam system.

Researchers from over 20 professorships will work with the equipment in the future

The new center has the advantage of merging all of Chemnitz University of Technology’s high-resolution transmission electron microscopy equipment in one location. More than 20 professorships of the faculties of mechanical engineering, natural sciences, and electrical engineering and information technology will use the equipment for their transdisciplinary and interdisciplinary basic and applied research. They will also collaborate with non-university research institutions, such as Fraunhofer Society institutes, as well as companies.

Background: Transmission Electron Microscopy Center at Chemnitz University of Technology

Construction of the new research building began in September 2023 under the direction of the State Office for Real Estate and Construction Management. The building was designed by Heinle Wischer Partnership of Independent Architects mbB in Dresden. The sculpture "Impact", created by Stefanie Welk from Walldorf near Heidelberg as part of the "Art in Architecture" competition, frames the building’s entrance.

Approximately 13.1 million euros were invested in the construction of the building. Of this amount, approximately 7.4 million euros were provided by the European Regional Development Fund and around 5.7 million euros by the Free State of Saxony. The project was co-financed with tax revenues based on the budget approved by the Saxon State Parliament. The German Research Foundation (DFG) and the Free State of Saxony each provided 3.5 million euros for the large-scale equipment. Professors Christoph Tegenkamp, Martin Wagner, and Bernhard Wunderle successfully acquired the funding on behalf of the three participating faculties at Chemnitz University of Technology.

For further information, please contact Prof. Dr. Andreas Undisz, phone +49 (0)371 531-34528, email andreas.undisz@mb.tu-chemnitz.de.

(Translation: Ulrike Lohr)

Dr. Chundong Wang, Professor at Huazhong University of Science and Technology in Wuhan (China), has been awarded a research fellowship for experienced scientists by the Alexander von Humboldt Foundation. The prestigious fellowship will enable him to conduct a one-year research stay at the Chemnitz University of Technology, starting in March 2026. At the Research Centre for Materials, Architectures and Integration of Nanomembranes (MAIN), he will work in the group of Dr Minshen Zhu at the Professorship of Material Systems for Nanoelectronics (Chair: Prof. Oliver G. Schmidt) in the Faculty of Electrical Engineering and Information Technology. 

Wang's research focuses on electrocatalysis and nanostructured functional materials, particularly for sustainable energy technologies such as hydrogen production and fuel cell technology. The aim of his work is to understand catalytic reactions at the atomic level and to develop advanced catalysts with precisely controlled electronic structures. In particular, he investigates single-atom catalysts and the role of electronic spin states in governing catalytic performance.

During his research stay in Chemnitz, Wang will collaborate with the groups of Dr Zhu and Prof Schmidt to develop microfluidic strategies for the controlled synthesis of single-atom catalysts at the MAIN Research Centre. The project aims to understand the influence of the electronic spin configuration of transition metal centres on catalytic reaction pathways and kinetics. By combining concepts from electrochemistry, nanotechnology and microfluidic technology, the aim is to enable more efficient and cost-effective production of catalysts. The expected results could contribute to the development of high-performance hydrogen fuel cell technologies, which are considered a key factor for sustainable energy systems.

Keyword: Humboldt Experienced Researcher Programme

The Alexander von Humboldt Foundation's Humboldt Research Fellowship for Experienced Researchers supports highly qualified scientists with established academic careers from all over the world in carrying out long-term research projects in Germany. It enables experienced researchers to carry out independent research projects in collaboration with a host institution and become part of the global Humboldt network. With this initiative, the foundation promotes international scientific exchange, strengthens long-term cooperation and supports outstanding research across disciplinary boundaries.

For further information, please contact Yvonne Ulbrich, email yvonne.ulbrich@etit.tu-chemnitz.de.

(Author: Yvonne Ulbrich)

Dr. Konstantin Hopf has been appointed Full Professor of Information Systems and Business Analytics at Chemnitz University of Technology as of 15 February 2026. He received his letter of appointment from the Vice President for Academic and International Affairs, Prof. Dr. Maximilian Eibl. The professorship is located at the Faculty of Economics and Business Administration.

Academic Career

Konstantin Hopf studied Information Systems at the University of Bamberg, where he also conducted research at the Bits-to-Energy Lab. His research focused on the application of machine learning methods to energy-related data in industry-oriented projects. He additionally gained international experience during a research stay at Copenhagen Business School.

In 2019, he completed his doctorate at the University of Bamberg with a dissertation entitled “Predictive Analytics for Energy Efficiency and Energy Retailing.” He subsequently worked as a Senior Researcher and Lecturer at the Chair of Information Systems and Energy-Efficient Systems (Prof. Thorsten Staake). As part of his habilitation, he established the research group “Machine Learning & Data Work in Organizations.” During this period, he was also a lecturer at Friedrich-Alexander-Universität Erlangen-Nürnberg and Leipzig University.

Since October 2025, Dr. Hopf has been acting professor of the Chair of Information Systems and Business Analytics at Chemnitz University of Technology.

Research and Teaching

Dr. Hopf’s research focuses on the integration of explainable machine learning methods into enterprise information systems for decision support. His work addresses both methodological challenges in Business Analytics and theoretical questions concerning the transformation of socio-technical systems through artificial intelligence (AI). His research is supported by numerous third-party funded projects with national and international partners from academia and industry. He regularly publishes in leading international journals in Information Systems and management science and presents his findings at major international conferences.

At Chemnitz University of Technology, he aims to further strengthen practice-oriented and explainable Business Analytics and to expand the application of AI-based decision support systems in critical energy infrastructures and in digital higher education. In addition, he plans to pursue strategic and organizational research on the use of Business Analytics and AI in companies.

In teaching, he contributes to the Bachelor’s and Master’s degree programs in Information Systems as well as to the Master’s degree programs in Business Intelligence & Analytics and Value Chain Management. He also offers complementary courses, including courses taught in English.

(Translation: Dr. Konstantin Hopf)

From December 1 to 4, 2025, the final week of the three-year collaborative project „WeSPICE" took place at the Tunisian university École Nationale d'Electronique et de Télécommunications de Sfax (ENET'COM). The project was funded by the German Academic Exchange Service (DAAD) as part of the Ta'ziz Partnership Program. The following staff members from the Chair of Measurement and Sensor Technology at Chemnitz University of Technology were involved in the project: Prof. Dr. Olfa Kanoun (Chair holder), Dr. Thomas Keutel (Project Manager Impedance Spectroscopy), Dr. Christian Viehweger (Working Group Leader and Project Manager Energy-Autonomous Sensor Systems), Dr. Rim Barioul (Working Group Leader Smart Wearables), Dr. Hiba Hellara (Project Manager Smart Wearables), and Mohamed Dhia Ayadi (Project Leader Micro- and Nanosensors (Nanogenerators)). The project was officially concluded with all participating organizations on December 4, 2025, in a ceremonial closing event attended by representatives from TU Chemnitz and the German Embassy in Tunis, as well as the Director of the DAAD Country Office.

Cross-Border Professional Development and Student Orientation

TU Chemnitz and ENET'COM in Sfax have worked closely in recent years with the Dräxlmaier Group, headquartered in Vilsbiburg, Lower Bavaria. The globally renowned premium vehicle manufacturer develops and produces wiring systems, electrical and electronic components, battery systems, and high-quality interiors for premium automotive manufacturers such as BMW and Porsche.

The project pursued three central thematic priorities with a special focus on knowledge transfer, participatory network building, and sustainable dialogue between academia, industry, and society:

• Professional development in ASPICE (Automotive SPICE): A total of 17 professionals were qualified, including seven instructors who will directly incorporate their knowledge into university teaching in the future, thereby ensuring sustainable knowledge transfer from industry to academia.
• Building an interdisciplinary network: A network of 25 partners from industry and society was established. Together with these non-university actors, „Improvements of Engineering Education Addressing Industry and Research Needs" were discussed from the perspectives of instructors and students. These participatory dialogue spaces enabled knowledge exchange between academia and practice and contributed to the needs-oriented development of engineering education.
• Student-oriented events: Over 360 students participated in a total of 32 participatory events including hackathons, soft skills seminars, women's empowerment workshops, job fairs, and green economy workshops. These formats strengthened the dialogue between universities, industry, and civil society and created sustainable bridges between academic education and professional practice.

ASPICE is an internationally recognized process model for evaluating and improving development processes in the automotive industry. Manufacturers and suppliers worldwide use it to ensure the quality, safety, and efficiency of software and system development. The project's final week was framed by a job fair and a workshop on integrating ASPICE into academic teaching. This made the international collaboration between research, industry, and education clearly visible and strengthened once again. „The parallel qualification of instructors and the practice-oriented offerings for students represent a sustainable contribution to strengthening international cooperation and training future professionals," emphasizes Prof. Dr. Olfa Kanoun, project leader on the German side.

Background: The WeSPICE Project

The collaborative project „We Establish Sustainable Program to Improve Commitment to Employability" (WE-SPICE)" was funded from 2023 to 2025 by the German Academic Exchange Service (DAAD) as part of the Ta'ziz Partnership Program with approximately 300,000 euros from the German Federal Foreign Office.

Background: Ta'ziz Partnership Program

The Ta'ziz Partnership Program, funded by the German Academic Exchange Service (DAAD) with resources from the Federal Foreign Office, promotes cooperation between German universities and partner institutions in the MENA region (Middle East and North Africa). The Arabic term  „Ta'ziz" means „strengthening" or  „consolidation" and clarifies the program's objective. In times of social and political change, universities and non-university actors are to be supported in order to promote reforms, scientific cooperation, and civil society participation.

For further information, contact Prof. Dr. Olfa Kanoun, Chair of Measurement and Sensor Technology

The Physik Journal, the member magazine of the German Physical Society (DPG, Deutsche Physikalische Gesellschaft e. V.), the most important specialist medium and central information forum for over 50,000 physicists of all disciplines in German-speaking countries, features an overview article in its January 2026 issue on two projects from the TUCculture2025 initiative of Chemnitz University of Technology in recent years that have combined art and physics in a special way. For example, the stele artwork “Thinking and Perception Model for the Phenomenon of Color” by Dresden artist Stefan Nestler, erected in 1998 as part of the construction of the Central Lecture Hall and Seminar Building at Chemnitz University of Technology, demonstrated how abstract concepts of modern physics can be explored through aesthetic experience. From the viewpoint of the end of 2025, the article puts the European Capital of Culture Chemnitz again into a retrospective focus.

Behind a largely regular arrangement of 187 metal steles, which have adorned the forecourt of the Central Lecture Hall and Seminar Building as a work of art since 1998, lies more than just an aesthetic object: it represents a kind of color in itself, a variation on what it conveys as its main message. What sounds like a somewhat convoluted but trivial statement is the result of more than three years of intensive and interdisciplinary scientific observation, funded in part by the projects “Chemnitz: Wood, Light, Sound” and “Wave Plays” as parts of the TUCculture2025 initiative. The work revealed that the artwork “Thinking and Perception Model for the Phenomenon of Color” is the world's largest scientifically described realization of a photonic crystal for electromagnetic waves and, at the same time, represents a phononic crystal that can be used fort he manipulation of sound waves. It thus represents forbidden regions, i.e., barriers for waves in several spectral ranges: the band gaps occur for both sound and radio waves, so that the artwork has its own “color” in each of these two domains.

This special connection between physics, art, and the worlds of human perception and metrological measurement is the focus of the overview article titled “Phoxonic Art” Herein, Prof. Dr. Angela Thränhardt, Professor of Theoretical Physics at Chemnitz University of Technology and Dean of the Faculty of Natural Sciences, and Dr. Thomas Blaudeck, Managing Director of the Research Center for Materials, Architectures, and Integration of Nanomembranes (MAIN) at Chemnitz University of Technology, explain how Stefan Nestler's stele arrangement allowed fundamental wave equations to be examined clearly and how numerical simulations, theoretical models, and metrological experiments were interlinked with the expertise of the faculties of Natural Sciences and Electrical Engineering and Information Technology. The adjective “phoxonic” in the deliberately pejorative title “Phoxonische Kunst” (Phoxonic Art) refers to the fact that several “forbidden regions” for the propagation of waves, i.e., band gaps, occur in one and the same object. This applies both to the photonic case, i.e., that related to light and electromagnetic waves in the field of established communication technologies, and to the phononic case, i.e., that are related to acoustics and hence sound. An interaction between these domains is also conceivable, at least in principle. This demonstrates the remarkable visionary nature of artist Stefan Nestler, who has imbued his artwork with a unique, phoxonian model of perception that is measurable and therefore verifiable.

The overview article also highlights that physical research not only unlocks new insights into abstract or complex phenomena in nature, but also opens up innovative avenues for science communication through its connection with art: as part of the TUCculture2025 projects, the artwork and its surroundings were transferred to a laboratory environment where the complex wave phenomena of photonics and phononics, such as scattering, interference, and diffraction, became audible and tangible in surprising ways. The artwork thus became the starting point for dialogue between scientists, friends of art, and the general public, for example at the Open House Days (TUCtage) since 2022 or the Christmas market at Chemnitz University of Technology. This is an example of bringing physics out of the “ivory tower” and into the urban and cultural space.

Beyond the specific topic, the overview article provides an outline of other projects with a “physical flavor” from the TUCculture2025 initiative of Chemnitz University of Technology, which since 2022 has bundled many of the university's activities at the interface of science, art, and society since 2022 and was geared toward 2025, when Chemnitz held the title of “European Capital of Culture.” The article also looks back on cultural projects and events in Chemnitz during the European Capital of Culture year that had a special connection to physics and thus became part of the broad cultural program in Chemnitz as scientific sprinklings.

The article has been available as a summary on the Physik Journal website (issue 01/2026) since January 5, 2026 (login required to access the PDF).

For further information, please contact Dr. Thomas Blaudeck, phone +49 (0)371 531-35610, e-mail thomas.blaudeck@main.tu-chemnitz.de, and Prof. Dr. Angela Thränhardt, phone +49 (0)371 531-37636, e-mail angela.thraenhardt@physik.tu-chemnitz.de.

(Author: Dr. Thomas Blaudeck, Translation: Tobias Bollig)

On 29 October 2025, Prof. Dr. Benanchour Saidi (Mohamed First University, Morocco) delivered a guest lecture titled “Criticality, Interculturality and Decoloniality: A Southern Praxis.” The event was part of his Visiting Scholar stay at the Junior Professorship of Intercultural Practice with a Focus on Digital Cultures at Chemnitz University of Technology, headed by Jun.-Prof. Dr. Yolanda López García. During his stay from September 2025 to January 2026, Prof. Saidi has been contributing as a Visiting Scholar to several courses in the Bachelor's and Master’s programs in Intercultural Communication. Together with Jun.-Prof. López García, he engaged with critically decolonial discourses as well as everyday practices and forms of knowledge related to interculturality. In doing so, they focused particularly on Latin American perspectives and those from the MENA region.

In his guest lecture, Prof. Saidi examined the epistemic intersections of criticality, interculturality, and decoloniality. He analyzed how discourses on interculturality are frequently depoliticized and rely on tokenistic notions of diversity, thereby unintentionally reproducing colonial structures of knowledge and power. At the same time, he cautioned against essentializing or reducing perspectives from the Global South, emphasizing that decoloniality must be oriented not merely reactively but transformatively.

Prof. Saidi advocated understanding criticality and decoloniality as ongoing epistemic and meta-ontological projects—processes of delinking, re-existence, and re-worlding. Such approaches require reflexivity, situatedness, and openness toward plural, multiversal articulations of Southern epistemologies.

Prof. Saidi’s Visiting Scholar stay fosters ongoing dialogue and academic exchange with Jun.-Prof. López García, whose research focuses on critical interculturality, (post)digital everyday practices, coloniality, and migration. Further collaborations are already being discussed to continue this dialogue beyond his current visit.

(Source: Junior Professorship of Intercultural Practice with a Focus on Digital Cultures)

The DFG Research Unit “Proximity-Induced Correlation Effects in Low-Dimensional Structures”, coordinated by Chemnitz University of Technology, investigates how proximity effects and interface engineering in atomically thin materials can be used to design next-generation quantum and optoelectronic devices. The research group explores epitaxial growth and intercalation of heavy carbon-group elements beneath graphene to tune its electronic and optical properties, ultimately forming hybrid systems with enhanced light-matter interaction.

In a recent publication in the renowned journal “Advanced Optical Materials”, researchers from the Professorships of Semiconductor Physics and Analytics on Solid Surfaces at TU Chemnitz reported a breakthrough in coupling light to graphene. Their work introduces tin (Sn) nanoantennas as a new plasmonic material capable of boosting the interaction between light and two-dimensional (2D) systems. This achievement not only expands the palette of plasmonic materials beyond conventional gold and silver but also strengthens graphene’s potential for future applications in molecular sensing, ultrafast photodetectors, and quantum nanophotonic devices.

From challenge to opportunity: how to make graphene absorb more light

2D materials, such as graphene, are highly regarded for their exceptional mechanical, thermal, and electronic properties. Notably, the absence of an energy bandgap in its electronic structure makes graphene particularly well-suited for broadband optical applications, including use in lasers and tunable optical modulators. Despite these remarkable traits, however, these materials interact only weakly with light; monolayer graphene absorbs a mere 2.3% of incident visible light under normal incidence. This low intrinsic absorption has long limited the use in optoelectronics.

One effective strategy to overcome this limitation involves the use of plasmonic nanoantennas, metallic nanostructures that act like tiny optical funnels. Much like a radio antenna concentrates widely spread (far-field) electromagnetic waves into a confined electrical signal, plasmonic antennas efficiently convert incident light into highly localized near-field plasmonic oscillations. This process focuses light into nanoscale “hot spots,” where the electromagnetic fields are dramatically intensified and concentrated far below the diffraction limit of light. Within these confined regions, interactions among electrons, phonons, and molecular vibrations occur much more efficiently, leading to enhanced optical processes such as surface-enhanced Raman spectroscopy (SERS), high-sensitivity photodetection, and photocatalytic energy conversion.

Sn nanoantennas: a new path to strong coupling

In their recent study, researchers from Chemnitz introduced Sn as a novel plasmonic medium. They successfully demonstrated that Sn nanoantennas can amplify the scattering intensity of graphene’s Raman-active phonons by more than two orders of magnitude. "This significant enhancement was achieved by positioning the graphene in dual-sided proximity to Sn nanostructures, which effectively act as plasmonic nanoantennas,” explains Dr. Narmina Balayeva, a postdoctoral researcher at the Professorship of Semiconductor Physics at Chemnitz University of Technology. “Using a technique called confinement epitaxy, a 2D metallic Sn layer first formed naturally between the graphene sheet and its silicon carbide (SiC) substrate, followed by the growth of Sn nanoislands directly on the graphene surface.”

A window into new physics

Enhancing light-matter interaction is not merely about improving device performance; it unveils possibilities to explore new regimes of quantum and optical physics. “When light is confined to dimensions comparable to atomic scales, it can form entirely new hybrid states, so-called polaritons, where electronic and optical excitations become inseparable,” says Dr. Zamin Mamiyev, a postdoctoral researcher at the Professorship of Analytics on Solid Surfaces, who coordinated the experiments. “Under such extreme spatial and optical confinement, we can probe energy-transfer mechanisms and quasiparticle dynamics that remain entirely hidden in conventional, macroscopic measurements. This effectively allows us to push the boundaries of sensing, photonics, and quantum technologies.”

The ability to manipulate and engineer materials one atomic layer at a time has inaugurated a new era of "materials-by-design," with hundreds of stable 2D crystals now available for combination into complex heterostructures. “Through targeted intercalation, inserting specific atoms between layers, we can form unusual material phases that are difficult to achieve otherwise and precisely control how these ultrathin materials interact at their interfaces,” adds Prof. Dr. Christoph Tegenkamp, head of the Professorship Analytics on Solid Surfaces and spokesperson for the DFG Research Unit. “This unprecedented control allows us to fine-tune and probe electronic and photonic interactions at a truly fundamental level, an essential capability for developing the next generation of high-performance quantum technologies.”

Looking ahead

Building on this success, the research team aims to further refine the plasmonic response of the metallic nanoantennas and their interface with graphene. By precisely optimizing these hybrid structures, they intend to achieve even stronger near-field coupling, ultimately paving the way for entirely new classes of quantum materials and functionalities. This work underlines Chemnitz University of Technology’s leading role in advancing research on 2D materials, plasmonics, and quantum nanophotonics, effectively bridging fundamental science and the future technologies that will shape the light-based devices of tomorrow.

Publication: Enhanced Light–Matter Interactions With a Single Sn Nanoantenna on Epitaxial Graphene; Zamin Mamiyev, Narmina O. Balayeva, Dietrich R.T. Zahn, Christoph Tegenkamp; Advanced Optical Materials

DOI:  https://doi.org/10.1002/adom.202500979

For further information please contact Prof. Dr. Christoph Tegenkamp, Telefon 0371 531-33103, E-Mail christoph.tegenkamp@physik.tu-chemnitz.de and Dr. Zamin Mamiyev, Telefon +49 371 531-3170, E-Mail zamin.mamiyev@physik.tu-chemnitz.de

(Source: DFG Research Unit “Proximity-Induced Correlation Effects in Low-Dimensional Structures”)

When you made your first coffee this morning, did you act on autopilot or did you plan each movement with the goal of coffee in mind? This simple question goes straight to the heart of a central distinction in neuroscience: the difference between actions that are habitual and those that are goal-directed. In a recent paper published in the renowned journal Trends in Neuroscience, Prof. Dr. Fred Hamker (Chair of Artificial Intelligence, Chemnitz University of Technology), Dr. Javier Baladron (University of Santiago de Chile), and Dr. Lieneke Janssen (Otto von Guericke University Magdeburg) challenge this classic distinction. They discuss how interaction between brain loops could efficiently shape our behavior – and potentially that of AI-Transformer models in the future.

Until now, researchers have assumed that our brain operates with two systems that control our thinking and behavior: a fast, automatic system and a slow, deliberate one — known, for example, from Daniel Kahneman’s bestseller Thinking, Fast and Slow. These systems are thought to produce either quick, habitual actions or considered, goal-oriented behavior. However, according to Hamker, Baladron, and Janssen, much of our everyday behavior arises from a complex chain of processes in the nervous system in which both systems are tightly interwoven.

The research team therefore proposes a new model: instead of distinguishing between “habitual” and “goal-directed” behavior, behavior should be viewed on a continuum. At the center of this are the loops connecting the basal ganglia, thalamus, and cortex — recurring circuits in the brain. “These loops enable both goal-directed and automatic behavior. The key factor is how strongly they interact: when shortcuts form within these circuits, behavior tends to become habitual. When all loops are fully traversed, actions remain more goal-oriented,” explains Hamker.

Their insights could also inspire new directions in AI research. The three researchers see parallels between the attention mechanisms of modern transformer networks — the technology that underlies large language models — and context processing in the human brain. “If AI models could in the future make use of habit-like shortcuts, they could become more efficient and energy-saving,” the researchers suggest.

Thus, the work of Hamker, Baladron, and Janssen not only opens up new perspectives on how the human brain functions but also on the future development of intelligent machines.

Publikation: Interacting corticobasal ganglia-thalamocortical loops shape behavioral control through cognitive maps and shortcuts, Fred H. Hamker (TU Chemnitz), Javier Baladron (Universidad de Santiago de Chile) and Lieneke K. Janssen (OVGU Magdeburg), Trends in Neurosciences, 9 October 2025, https://doi.org/10.1016/j.tins.2025.09.006 

Contact: Prof. Dr. Fred Hamker, Chair of Artificial Intelligence at Chemnitz University of Technology, Telefon +49 (0)371 531-37875, email fred.hamker@informatik.tu-chemnitz.de.

A special highlight of the winter semester is the 12th “Tag des wissenschaftlichen Nachwuchses” at Chemnitz University of Technology (TUC). The Centre for Junior Scientists (ZfwN) cordially invites all interested participants to join the event on 11 November 2025, from 10:30 a.m. to 5:30 p.m., in the Central Lecture and Seminar Building, Reichenhainer Straße 90. The event is aimed at prospective doctoral candidates, doctoral researchers, postdocs, supervisors, and all other interested persons. Participation is free of charge, but online registration is requested. This year’s event is held under the theme “Academic Qualification in the Age of AI”. It offers various insights into the opportunities and challenges that artificial intelligence brings to research, teaching, and career development.

Program and Key Topics

The day will begin at 10:30 a.m. with an “Opening and Moderated Talk with Early-Career Scientists”, in which young researchers will share insights into their doctoral experiences. The session will conclude with Prof. Frank Asbrock, Ombudsperson for Good Scientific Practice, who will highlight key aspects of responsible conduct in research.

During the Networking Break (12:30–2:00 p.m.), participants will have the opportunity to exchange ideas with representatives from various faculties and other university institutions and to establish new contacts.

In the afternoon, the session from 2:00 to 3:30 p.m. will focus on the main theme: “Wissenschaftliche Qualifikation im KI-Zeitalter – Chancen, Herausforderungen und Perspektiven”.

After a short Break (3:30–4:00 p.m.), two parallel sessions will follow from 4:00 to 5:30 p.m.:

• The PhD Journey from Different Perspectives – with Prof. Dr. Anja Strobel (Faculty of Behavioural and Social Sciences) and Prof. Dr. Martin Wagner (Faculty of Mechanical Engineering)
• Postdoc Roundtable: Sharing Experiences – an open discussion format for postdoctoral researchers from various disciplines.

The event will be held in both German and English. Each session will be conducted in the language of its respective presentation title.

Further information and the registration link are available online at: https://mytuc.org/tztm

Stay Informed

The ZfwN newsletter provides regular updates on current workshops, events, and news related to doctoral studies, career planning, and academic development. Interested persons can subscribe online.

For questions, feedback, or suggestions regarding the continuing education program or the “Tag des wissenschaftlichen Nachwuchses”, the ZfwN team is happy to assist.

Contact: Centre for Junior Scientists, E-mail zfwn@tu-chemnitz.de

(Author: Dr. Nadia Lois)

Personal pronouns like “I” and “you” are among the most common words in the English language – but that doesn’t mean they occur equally often in all kinds of texts. “If you think about it, you wouldn’t really expect to find any personal pronouns in cooking recipes”, says Christina Sanchez-Stockhammer, Professor of English and Digital Linguistics at Chemnitz University of Technology. That’s because recipes have a very special way of using language: in a typical sentence like “Add potatoes and cover with salted water,” recipes miss all the opportunities to use personal pronouns. Instead of saying “YOU add potatoes and cover THEM with salted water,” recipes only imply the “you” at the beginning of the instruction and leave out the “them” other texts would use to refer to the potatoes a second time. To find out if this is systematic, Sanchez-Stockhammer investigated a corpus of 280 recipes from the internet. She found personal pronouns in recipes after all – just less than half as many as in other texts. And when recipes use the pronoun “it”, it often has a grammatical function, e.g. in “It takes a bit of time, but it's worth it.”

The researcher also determined how common personal pronouns are in the individual parts of the recipes. The titles did not contain any, and the ingredients lists very rarely, like in “540g white fish chunks (I like to use pollock or basa)”. The introduction, by contrast, used even more personal pronouns than many other types of English texts. One reason for this is that the introduction of a recipe often tells a personal story, in which the authors explain why they love that particular food, or how it has come to them – for example through their grandmother, who always used to bake that delicious cake.

Introductions to online recipes are often so long that many users on the internet complain about having to read a whole life story before reaching the actual recipe. At first glance, it would seem that this is an internet phenomenon, with recipes imitating cooking blogs. But Sanchez-Stockhammer’s study reveals that giving recipes a personal touch isn’t new at all: for example, a popular Australian cookbook raved about apple dumplings as early as 1864 (“we hardly know anything better”).

The linguist sums it up: “Cooking recipes don’t just tell you how to prepare a meal – they are full of emotions. Anyone who shares a recipe also wants to share their joy about food. And the role of personal pronouns in all this is to establish a relationship between the author, the reader and the recipe.”

For an entertaining summary of the study and the stories behind it, tune in to the latest episode of Sanchez-Stockhammer’s science podcast, ‘Linguistics Behind the Scenes’.

Read the full paper: Christina Sanchez-Stockhammer. 2025. The linguistic functions of personal pronouns in online cooking recipes. Anglistik 36(2). 129-156. DOI:  https://doi.org/10.33675/ANGL/2025/2/10

Listen to the podcast on YouTube (https://www.youtube.com/watch?v=smYb0pm-1x8), Spotify (https://open.spotify.com/episode/4OGU0cbQqp9MjisAnySBJA) and Apple Podcasts (https://podcasts.apple.com/us/podcast/are-cooking-recipes-about-you-and-me-cookbook-linguistics/id1799779038?i=1000729402104).

Information about the podcast “Linguistics Behind the Scenes”: https://www.tu-chemnitz.de/phil/english/sections/edling/sciencecommunication/podcast.php

For any questions, please get in touch with Prof. Christina Sanchez-Stockhammer, tel. +49 (0)371 531-32444, email christina.sanchez@phil.tu-chemnitz.de.

Humans already cooperate closely with robots, for example in industrial settings. This is likely to increase in the future. But what do human-robot teams actually talk about at work? And how? "We want to know if people speak differently when they’re working in a team with a robot compared to a team with another human," says linguist Prof. Christina Sanchez-Stockhammer from Chemnitz University of Technology. Her interdisciplinary team of researchers from neuro-robotics and linguistics conducted experiments in which human participants performed a task together with an industrial robot arm with speech functions. "The obvious choice was to have them assemble a simple IKEA shelf together, because that can be done even without instructions," reveals robotics engineer Sascha Kaden. "During the process, we recorded the teams and then transcribed and analysed everything they said," explains linguist Sasha Coelho.

As the researchers expected, purely human teams produced more statements, explanations and particularly questions, while the robot arm received more direct instructions than humans. "But we were surprised to find almost as many emotional statements in the human-robot teams as between humans." For example: "You're doing a good job."

The full study is now freely available online in open access. "I believe research like this is not only interesting for academics, but also for the general public," says Christina Sanchez-Stockhammer. "But there’s often not much room for explanations in research articles, which makes them harder to follow." That’s why the linguist provides engaging and accessible explanations of her recent publications in matching episodes of her podcast, "Linguistics Behind the Scenes". The latest episode focuses on artificial intelligence and the robot study.

Read the full paper at: Sasha Genevieve Coelho, Sascha Kaden, Marina Beccard, Florian Röhrbein & Christina Sanchez-Stockhammer. 2025. "Another bit. Upwards. Okay, stop." Do we talk differently to humans and robots when assembling a shelf together?, Proceedings of the Mensch und Computer 2025 (MuC '25), 465-470. DOI: https://doi.org/10.1145/3743049.3748536

Listen to the podcast on YouTube (https://www.youtube.com/watch?v=DNsQsbYqQFs), Spotify (https://open.spotify.com/episode/1R7SB5BuqfoEQNk5cVZR7L) and Apple Podcasts (https://podcasts.apple.com/us/podcast/do-you-say-thank-you-to-a-robot-when-humans-talk-to-ai/id1799779038?i=1000725638252).

Information about the podcast “Linguistics Behind the Scenes”: https://www.tu-chemnitz.de/phil/english/sections/edling/sciencecommunication/podcast.php

For any questions, please get in touch with Prof. Christina Sanchez-Stockhammer, tel. +49 (0)371 531-32444, email christina.sanchez@phil.tu-chemnitz.de.

(Translation: Prof. Christina Sanchez-Stockhammer)

Prof. Dr. Olfa Kanoun, holder of the Department of Measurement and Sensor Technology at Chemnitz University of Technology, was awarded the President of the Republic of Tunisia's prize for the best Tunisian researcher living abroad at a ceremony in Tunis on 28 August 2025.

The National Prize for Science and Technology is awarded by the Tunisian Ministry of Higher Education and Scientific Research (MESRS). It honours Tunisian researchers and inventors living in Tunisia or abroad who have distinguished themselves through outstanding scientific achievements or technological innovations. The research prize is awarded according to strict criteria that go far beyond mere publication performance. Scientific visibility through publications and doctorates, innovative strength through patents or new methods, the economic and social benefits of research projects, and international presence through collaborations, conferences and awards are all taken into account. In the case of Prof. Dr. Kanoun, the award recognises in particular her scientific excellence and the technological innovation of her internationally recognised research work.

“This award represents an important milestone in my academic and scientific career. I regard it as recognition of many years of intensive research and the dedicated commitment of our entire professorship. At the same time, it is a strong motivation for us to continue on the path we have chosen with determination and dedication and to further advance our scientific work,” emphasises Prof. Dr. Kanoun.

"We warmly congratulate Professor Kanoun on this prestigious award and are delighted that our colleague has received this recognition. The award once again underlines the excellence of the scientific achievements and technological innovations that Professor Kanoun and her team are making in the field of materials and intelligent systems," says Prof. Dr. Anja Strobel, representative of the Rector and Vice-Rector for Research and University Development at Chemnitz University of Technology.

Commitment to Tunisia and promoting young talent

Although Prof. Dr. Kanoun works in Germany, she has always maintained close ties with Tunisia. She has supervised more than 100 theses by Tunisian engineering and master's students, as well as over 20 doctoral and postdoctoral students. In addition, she has organised more than 15 international summer schools in Tunisia and developed over 30 research and mobility projects with Tunisian institutions, which were funded by the German Academic Exchange Service (DAAD) and the European Union.

Innovation, patents and international projects

As the (co-)owner of seven patents in the field of sensor technology and nanomaterials, Kanoun is also heavily involved in innovation. She supported the founding of NanoSen GmbH, a start-up specialising in innovative force sensors. She also coordinates numerous large-scale international projects at EU level and in the context of joint projects of the German Research Foundation.

Prof. Dr. Kanoun has also founded and chaired several renowned international conferences, including the International Workshop on Impedance Spectroscopy (IWIS) and the Multi-Conference on Systems, Signals and Devices (SSD). She has been elected IEEE Distinguished Lecturer twice (2016 and 2022).

About Prof. Dr. Olfa Kanoun

Born and raised in Sfax, Prof. Dr. Olfa Kanoun studied in Germany and established herself internationally as a leading expert in the fields of sensor technology, impedance spectroscopy and nanomaterials.

Prof. Dr. Kanoun received her doctorate from the University of the Federal Armed Forces in Munich in 2001 and was awarded the dissertation prize by the Working Group of University Lecturers for Measurement Technology (AHMT e. V., Germany). In the same year, she founded the ‘Impedance Spectroscopy’ working group at the Institute for Sensor Technology and Measurement Systems at the University of the Federal Armed Forces in Munich (Prof. Dr. Hans-Rolf Tränkler). In 2006, she was appointed adjunct professor and head of the Department of Measurement Technology at the University of Kassel. Since 2007, she has been a full professor at Chemnitz University of Technology, where she heads the Chair of Measurement and Sensor Technology. After founding the International Workshop on Impedance Spectroscopy (IWIS) in 2008 and the Advanced School on Impedance Spectroscopy in 2017, she launched the Technical Committee Impedance Spectroscopy (TC2) in 2018. Prof. Dr. Kanoun is now a leading and internationally recognised scientist in the field of sensors and sensor systems.

In the SCOPUS literature database, she tops the list of authors on impedance spectroscopy in Germany and the list of authors worldwide in the field of sensor systems for impedance spectroscopy. She has published over 700 peer-reviewed scientific publications, which have been cited more than 8,000 times. Her work has led to decisive advances in the development of novel intelligent sensors, energy-autonomous systems and new diagnostic methods for batteries, health, the environment and industry. In 2022, she was honoured with the Technical Award of the IEEE Instrumentation and Measurement Society for her pioneering achievements.

(Translation: Prof. Dr. Olfa Kanoun, Anne Eichhorn)

Collagen fibrils are the basic building blocks of skin, tendons, ligaments, and bones. They hold our bodies together. Fats and oils have long been used to soften and protect leather, which consists of collagen molecules. However, it is not known how many fat molecules are contained in natural collagen fibrils. Knowing the precise chemical composition of collagen fibrils is important for understanding biochemical processes involved in tissue growth, aging, and disease. In chemistry, the various molecular components are usually separated to study the properties of pure substances. However, biological systems contain thousands of different chemical molecules, all of which are likely important.

A research team of physicists and chemists from the Faculty of Natural Sciences at Chemnitz University of Technology discovered that triacylglycerols—a very common type of natural fat molecule—assemble between collagen molecules, thereby influencing the cohesion of much larger collagen fibrils. This finding is essential for understanding the biomechanics of connective tissue. It also demonstrates how embedded lipids can affect binding forces between proteins at the molecular level.

The researchers examined collagen fibrils from chicken tendons and discovered that they contained a unexpectedly high amount of triacylglycerols, also known as neutral fats. These fat molecules comprise about nine percent of the volume of dry collagen fibrils and are randomly incorporated into the crystal lattice of collagen molecules. The fat molecules act as plasticizers, reducing the water content of the collagen fibrils. This finding challenges the current understanding of the chemical composition of natural collagen fibrils.

To determine the triacylglycerol content and its effects on the mechanical properties of individual collagen fibrils, Dr. Martin Dehnert and Prof. Dr. Robert Magerle of the Chair of Chemical Physics at Chemnitz University of Technology developed a new analysis protocol based on atomic force microscopy. They use a washing sequence in which the fats adhering to the fibrils are first removed with a nonpolar solvent (hexane). Then, they dissolve the fat molecules out of the interior of the fibrils using a polar solvent, a mixture of dichloromethane and methanol. After each washing step, they examined the resulting changes in the collagen fibrils using atomic force microscopy. This allows the shape and mechanical properties of the collagen fibrils, which are approximately 100 nanometers thick, to be determined very accurately. Finally, using Raman and NMR spectroscopy, they identified the fats contained in the collagen fibrils as triacylglycerols.

"Our findings show how fats and water interact in natural collagen fibrils," explains Robert Magerle. He adds: "This suggests that there may be a link between the fats present in our diet and the biomechanics of connective tissue. We plan to investigate this in more detail in the future.”

Publication: Triacylglycerols affect the water content and cohesive strength of collagen fibrils, M. Dehnert, T. Klose, Y. Pan, D. R. T. Zahn, M. Voigtländer, J. F. Teichert, R. Magerle, Soft Matter (9 Sept 2025).

DOI: https://doi.org/10.1039/D5SM00696A

Further information can be obtained from Dr. Martin Dehnert, telephone +49-371-531-39916, email martin.dehnert@physik.tu-chemnitz.de, Prof. Dr. Robert Magerle, telephone +49-371-531-38033, email robert.magerle@physik.tu-chemnitz.de.

Figure caption:

In a major step toward intelligent and collaborative microrobotic systems, researchers at the Research Center for Materials, Architectures and Integration of Nanomembranes (MAIN) at Chemnitz University of Technology have developed a new generation of autonomous microrobots—termed smartlets—that can communicate, respond, and work together in aqueous environments.

These tiny devices, each just a millimeter in size, are fully integrated with onboard electronics, sensors, actuators, and energy systems. They are able to receive and transmit optical signals, respond to stimuli with motion, and exchange information with other microrobots in their vicinity. The findings are published in the prestigious journal Science Robotics under the title “Si chiplet–controlled 3D modular microrobots with smart communication in natural aqueous environments”. Unlike previous generations of microrobots that relied on much larger wireless control setups to mitigate limited onboard functionality, smartlet microrobots are powered by integrated photovoltaic cells, controlled by tiny microchips, and capable of optical communication through embedded micro-LEDs and photodiodes. "For the first time, we demonstrate a self-contained microrobotic platform that not only senses and moves in water but also interacts with other microrobots in a fully programmable and autonomous manner," explains Prof. Oliver G. Schmidt, one of the corresponding authors of the study and Scientific Director of MAIN.

The microrobots are built using a flexible origami-inspired approach, based on smart multilayer patterned materials, allowing the flat electronic system to roll and fold up autonomously into a tiny scroll-adorned hollow 3D cube, with interior as well as exterior functionality. This opens up the extra surface space needed for each cube to carry its own solar energy harvester, computational logic, and an optical signaling system, in addition to interacting external faces and inboard locomotion. When immersed in water, these smartlets can move up and down by buoyancy forces created by bubble generating engines that fill the hollow interior of the smartlet with gas. They can also emit pulses of optical signals to broadcast instructions to other smartlets nearby. This setup enables multi-robotic interactions in water, including stimulus-driven movement, synchronization, and coordination among multiple smartlets. For example, when one unit receives a light signal, it can decode the information using its onboard processor, triggering a coordinated motion or behavior in others. “The idea of using light as both energy and information opens up a compact and scalable way to create distributed robotic systems,” adds Dr. Vineeth Bandari, co-corresponding author and research group leader at MAIN.

One of the key innovations lies in the smartlets’ use of a “wireless communication loop” that does not require any external cameras, magnets, or antennas. Optical messages are interpreted locally on each robot using custom-coded logic stored on their microchips. The smartlets make use of innovative soft-bonding to origami-films to attach custom microscopic silicon chiplets, called lablets, which were developed in an earlier European Union funded project led by Prof. Dr. John McCaskill, a co-corresponding author and member of MAIN. This permits decentralized control and collaboration—an essential foundation for creating robotic collectives that behave in a coordinated yet flexible way.

Beyond the laboratory, the potential applications of such microrobots are wide-ranging. Because they are untethered, biocompatible, and able to respond to environmental cues, these devices could one day assist in tasks such as monitoring water quality, performing minimally invasive medical diagnostics, or probing confined biological environments. Their ability to form interactive, stimulus-responsive colonies could also be used in soft robotics, autonomous inspection systems, or distributed sensing networks. Dr. Yeji Lee, co-author and specialist in active multi-layer microfabrication, whose recently completed PhD research provided vital contributions, emphasizes that this work is just the beginning. “We’re exploring ways to further increase autonomy by adding chemical and acoustic sensing modules. These smartlets could evolve into multifunctional platforms that sense, act, and adapt in complex fluidic environments.”

Looking forward, the team envisions the progressive evolution of these microrobots into dynamic systems that resemble colonies of digital organisms. Much like zooids in colonial animals such as siphonophores, each smartlet can serve a specialized function—sensing, communicating, moving—and together form an emergent robotic organism. “We’re still far from creating artificial life,” cautions Prof. John McCaskill, who was a founding Director of the European Center for Living Technology in Venice, “but we are starting to see how distributed intelligence and modular hardware can build systems that begin to mirror the adaptive, communicative behaviors of living collectives.” By building such self-contained, communicative microrobots, the Chemnitz team is not only addressing fundamental challenges in microrobotics but also laying the groundwork for future systems that operate, evolve, and perhaps even self-organize—inside water droplets, tissue scaffolds, or miniature ecosystems.

Publication: Si chiplet–controlled 3D modular microrobots with smart communication in natural aqueous environments, Yeji Lee, Vineeth K. Bandari, John S. McCaskill, Pranathi Adluri, Daniil Karnaushenko, Dmitriy D. Karnaushenko, Oliver G. Schmidt, Science Robotics (20 Aug 2025)

DOI: https://doi.org/10.1126/scirobotics.adu6007

For further information please contact Prof. Dr. Oliver G. Schmidt, Scientific Director of the Research Center MAIN and Chair of the Professorship of Material Systems for Nanoelectronics at the TU Chemnitz, E-Mail oliver.schmidt@main....

Scientists from the Professorships of Experimental Physics with focus Technical Physics (Head: Prof. Dr. Thomas Seyller) and Theoretical Physics of Quantum Mechanical Processes and Systems (Head: Prof. Dr. Sibylle Gemming) at Chemnitz University of Technology are investigating the functionalization of low-dimensional electron gases as part of the research unit “Proximity-induced correlation effects in low-dimensional structures (FOR 5242)” (Spokesperson: Prof. Dr. Christoph Tegenkamp).

In their latest publication in the renowned journal “Nature Communications”, the research team led by Dr. Philip Schädlich, scientific associate at the Chair of Experimental Physics with focus Technical Physics, has demonstrated the synthesis of bismuthene, protected by graphene, in close cooperation with the Peter Grünberg Institute at Forschungszentrum Jülich. The synthesis is based on the process of intercalation - the introduction of bismuth atoms at the interface between graphene and the substrate material silicon carbide. However, this initially produces an electronically inactive “precursor” layer of bismuth atoms, which can be reversibly activated by additional intercalation of hydrogen to the quantum spin Hall insulator bismuthene.

The position is crucial

For a long time, the hydrogen-induced “switching on” of the quantum material was a mystery to researchers, but it is now clear: "The adsorption site, i.e. the position of the bismuth atoms in relation to the substrate, plays a decisive role. While in the “precursor” state each bismuth atom has bonds to three atoms of the substrate, in the bismuthene state it is only one atom," explains Niclas Tilgner, who played a key role in advancing the study as a PhD student. In this way, the characteristic in-plane bonds can form the honeycomb structure of bismuthene.

The solution was found with the help of the synchrotron-based measurement method of “X-ray standing wave imaging”, which the researchers used at the Diamond Light Source in Didcot, UK. The partners from Jülich are proven experts in this field. Prof. Dr. Christian Kumpf, group leader at Forschungszentrum Jülich, explains: "In this measurement technique, the superposition of incident and diffracted X-rays forms a standing wave whose phase can be varied via the photon energy used. In this way, photoelectrons are preferentially emitted from certain areas of the unit cell, enabling the atomic structure to be determined element-specifically and with a spatial resolution of less than a hundredth of a nanometer."

In this study, the researchers funded by the German Research Foundation (DFG) are also relying on a combination of experimental data and results from density functional theory (DFT). "The collaboration of partners from both experimental and theoretical physics makes it possible to reliably describe the complexity of such a system. Experimental structural data enables the modeling of the band structure, which in turn helps to interpret the results of photoelectron spectroscopy," says Dr. Philip Schädlich.

Topologically protected edge channels have the potential for dissipation-less current flow

With their research results, the scientists are making an important contribution to a highly topical issue in solid-state physics: the question of whether all materials with a band gap - i.e. electrical insulators - exhibit the same quantum physical properties as the vacuum - i.e. a state without any conductive structure. The surprising answer is: no. Because there is a whole class of new materials that behave completely differently despite their band gap - so-called topological insulators. Like ordinary insulators, these also have a band gap in their bulk and therefore do not conduct electricity. However, an astonishing effect occurs at their surfaces or edges - conductive channels are created here in which electrons can flow without dissipation. These edge channels are robust against perturbations such as impurities or small defects. They are therefore referred to as topologically protected states.

“Topology is not about shapes, but about the basic structure - for example, how many holes an object has,” explains Niclas Tilgner. An orange, for example, has zero holes, whereas a donut has one. This number - known as the genus - cannot be changed without fundamentally restructuring the object. In solid-state physics, there is a similar distinction between ordinary and topological insulators. When a material changes from one type to the other - metaphorically speaking from a donut to an orange - its band structure must change. This creates a transition region in which electrons can suddenly flow freely: the metallic edge channel. Quantum spin Hall insulators such as bismuthene are particularly fascinating. Their conductive edge channels are not only stable, but also spin-polarized: In this case, the electron spin determines the direction of movement of the electrons. These properties open up far-reaching prospects for current research in electronics and quantum physics.

Background: DFG research unit “Proximity-induced correlation effects in low dimensional structures” under the leadership of Chemnitz University of Technology

Phenomena such as the one described above are at the heart of the DFG research unit headed by Prof. Dr. Tegenkamp. The research unit, which has received over four million euros in funding, is dedicated to investigating correlation effects in 2D materials and is now looking forward to a second funding period. The objective is to manipulate 2D materials in a targeted manner in order to investigate exotic effects such as superconductivity, charge density waves, Mott states, the quantum Hall effect and Klein tunneling.

Publication: Niclas Tilgner, Christian Kumpf, Philip Schädlich et al: Reversible Switching of the environment-protected quantum spin Hall insulator bismuthene at the graphene/SiC interface, Nature Communications (2025).

DOI: https://doi.org/10.1038/s41467-025-60440-x

For further information, please contact Dr. Philip Schädlich, e-mail philip.schaedlich@physik.tu-chemnitz.de.

(Authors: Niclas Tilgner, Dr. Philip Schädlich, Christian Kumpf)