In this DFG funded project we study a new class of biodegradable electrets and ferroelectrets based on Polylactide Acid (PLA) and its derivatives. These have the potential of an adjustable biodegradability and suited electrical performance, i.e., sufficient charge storage and thermal charge stability. Based on our previous research, also funded by DFG (KU 3498/1-1, SE 941/21-1) and in order to obtain the energy efficient electromechanical conversion for these mechanical-based sensors, we propose using a polymer-air composite (hybrid) structure with geometrically defined air-filled and electrically charged voids. These mechanically soft hybrid systems allow achieving high piezoelectric coefficients even for very weak polar polymers such as PLA. Therefore, investigating and improving charge storage and its thermal stability is essential, since these are the most important properties to obtain high and persistent piezoelectric coefficients in biodegradable electret and ferroelectret hybrids to be used in mechanical-based sensors for quantities such as force, pressure, torque and acceleration.

Original Publication: S. Zhukov, X. Ma, H. von Seggern, G. M. Sessler, O. Ben Dali, M. Kupnik, and X. Zhang, “Biodegradable cellular polylactic acid ferroelectrets with strong longitudinal and transverse piezoelectricity”, Applied Physics Letters, vol. 117, no. 11, p. 112 901, 2020. DOI: 10.1063/5.0023153.

Conventional methods for directional control of light, such as the use of mirrors, have significant limitations as they can cause wavelength-dependent losses or even complete absorption of light. In particular, at high levels of light power, the optical properties of solid-state materials are often limited. Instead, SOPHIMA employs non-contact methods for manipulating light by utilizing ultrasonic waves (Sono) to control light in gases. The project involves extensive fundamental research for developing novel methods, such as Sono-Photonic Light Waveguides, Phase Modulators, non-linear and active optical elements, as well as back-action-free optical methods for measuring acoustic phenomena and sensors in gases.

By integrating non-linear optics, laser physics, and electrical/ultrasound technology, SOPHIMA opens up a new field of research with great potential for scientific and industrial applications. The project aims to enable fundamental control and guidance of light in a novel and innovative way, thereby revolutionizing a multitude of applications in various fields.

Original Publication:

Acousto-optic modulation of gigawatt-scale laser pulses in ambient air; Yannick Schrödel, Claas Hartmann, Tino Lang, Jiaan Zheng, Max Steudel, Matthias Rutsch, Sarper H. Salman, Martin Kellert, Mikhail Pergament, Thomas Hahn-Jose, Sven Suppelt, Jan Helge Dörsam, Anne Harth, Wim P. Leemans, Franz X. Kärtner, Ingmar Hartl, Mario Kupnik, Christoph M. Heyl; „Nature Photonics“, 2023; DOI: 10.1038/s41566-023-01304-y

SOPHIMA website of the Carl Zeiss Foundation

Listen2Future aims to promote the potential of piezoelectric acoustic transducers for new solutions in the fields of health, digital industry and energy. Acoustic transducer solutions and the underlying key technologies can be the answer to many of the challenges arising from new fields of application for an increasingly digitalized society. In medical and industrial products, the need for “Micro-Electro-Mechanical-Systems” (MEMS) is increasing. Such minaturized electromechanical transducers with low power consumption in the form of microphones and ultrasonic transducers are being further developed and researched in this project. The goal is to improve acoustic sensors with new piezoelectric materials and technologies to outperform existing sensors based on capacitive MEMS technologies and to open up new application areas.

The project involves 27 partners from academia and industry from seven nations in the European Union.

Check out the Listen2Future website

Leg prostheses, orthoses and exoskeletons become active movement assistance systems by individually and situation-specifically detecting their users’ movements and providing them with appropriate force and torque support. Such an assistive device can be “seamlessly” integrated into the human body schema if it is able to automatically recognize different movement intentions and consequently generates an intuitive and predictable motor behavior. In this way, it integrates seamlessly into the daily experiences of movement.

The research training group LokoAssist (RTG 2761 Project number 450821862) brings together researchers from different disciplines, such as human sciences, computer science, engineering, and medicine, in order to tackle the diverse and interdisciplinary challenges in the development of such assistance systems. In particular, the project area A3 investigates integrated sensors and sensor fusion in order to measure and analyze the state variables of the user as well as the assistance system, which is crucial for suitable assistance.

LokoAssist website

Every year, more than 20 million square meters of sandwich elements are produced for the construction sector in Germany, and as many as 200 million in total in the European Union. There is potential for savings in materials and energy by optimizing production processes. To promote resource-efficient production of sandwich elements, the German Federal Ministry for Economic Affairs and Energy has launched a new research project called “Resource-efficient sandwich elements through non-destructive monitoring for lightweight construction ReSaMon.”

Sandwich elements consist of two thin metallic face sheets and a core of rigid polyurethane foam and are important building products. However, potential weak points such as damage due to heat-induced stresses are not always detectable in the manufacturing process and only appear during processing on the building site. This leads to complaints, longer construction times and other problems.

The “ReSaMon” project team will develop a new non-destructive ultrasonic measurement technique that can immediately detect flaws and inaccuracies to identify potential weak points and changes in material properties during the production process. The measurement technology works without contact and therefore does not interfere with the production process. The construction industry and end users will benefit from this technology.

The project consortium consists of industry partners, sandwich panel experts, metrology specialists and simulation experts who are bringing their expertise together to achieve a better understanding of the influences of production on product properties. The project partners include the Fraunhofer Institute for Structural Durability and System Reliability LBF, the Institute for Steelwork Technology IFSW, the company Inoson, manufacturers such as ArcelorMittal and Covestro Deutschland, and us, the Measurement and Sensor Technology (MuST) department at TU Darmstadt as a research partner focusing on ultrasonic measurement technology.

In Industry 4.0, the quality of process data is of crucial importance for all subsequent processes. Connecting elements are particularly suitable for this as they are in the force flow and can be replaced without constructive changes.

As part of the DFG project SiSmaK (priority program 2305: Sensor-integrated machine element),

the FG Measurement and Sensor Technology is working on the multi-axis measurement of mechanical loads in screws. This allows bending moments to be recorded in addition to the axial forces used for the configuration. Despite all adaptations to the machine element, the load-bearing capacity is to be maintained and universal applicability is to be ensured by full electronics integration and energy approach.

In addition, the design methodology for mechatronic systems is being extended to sensor-integrated machine elements as part of this project.(DFG project no. 466650813)