Smart Materials and Devices
Smart materials are characterized by their multifunctional properties, in particular, sensing and actuation functions. Important examples are shape memory alloys,(SMAs), piezoelectrics, as well as multiferroic materials. These materials show large abrupt changes of their physical properties near phase transformations. Therefore, they are predestined for applications on the micro- and nano-meter scale.
Shape memory alloys can be reversibly deformed by strain values exceeding 10% and still recover their original shape by heating (thermal shape memory effect) or by applying a magnetic field (magnetic shape memory effect). These properties are used for the development of novel smart actuators and multifunctional devices
- Multiphysics simulation of smart devices
- Multifunctional devices: Microgripper, Microvalves, Microscanner, Micropositioning, Microdamping
Smart materials are useful to convert waste heat or vibrational energy in electricity (energy harvesting). Another important topic is solid-state cooling. Shape memory alloys show very large changes of latent heat in the order of 20 J/g that are exploited for cooling and heat pumping applications.
Nanotechnologies are used to develop mechanically active nanostructures showing sensing and actuation functions. Novel in-situ measurement methods are being developed to characterize their physical properties in order to understand scaling and size effects.
Guest editors: M. Kohl, S. Seelecke, U. Wallrabe
This Special Isssue collects the emerging research activities in the field of cooperative microactuator systems, which are expected to generate new synergies, e.g. through parallelization, cascading and multistability as well as through inherent sensing.More…
Researchers at KIT and Tohoku University (Japan) succeeded in significantly enhancing the electrical power of thermomagnetic generators with respect to footprint. This research is the front topic of the December 2020 Issue of the Energy Journal ‘Joule’.
Original Publication: Joel Joseph, Makoto Ohtsuka, Hiroyuki Miki, and Manfred Kohl: Upscaling of Thermomagnetic Generators Based on Heusler Alloy Films. Joule, 2020.
Awarded for the Development an Realisation of an Ultra-compact Photodetector: Prof. C Koos, Prof. M. Kohl and Physicist S. Mühlbrandt (from left to right, Photo: T. Niedermüller, GSS).