000K  utf8
1100  $c2020
1500  eng
2050  urn:nbn:de:gbv:8:3-2021-00039-6
2051  10.3390/iecat2020-08501
3000  Arivanandhan, Gowtham
3010  Curtis, Sabrina Michelle
3010  Kohl, Manfred
3010  Li, Zixiong
3010  Quandt, Eckhard
3010  Velvaluri, Prasanth
4000  Temperature Homogenization of Co-Integrated Shape Memory—Silicon Bimorph Actuators  [Arivanandhan, Gowtham]
4209  The high work density and beneficial downscaling of shape memory alloy (SMA) actuation performance provide a basis for the development of actuators and systems at microscales. Here, we report a novel monolithic fabrication approach for the co-integration of SMA and Si microstructures to enable SMA-Si bimorph microactuation. Double-beam cantilevers are chosen for the actuator layout to enable electrothermal actuation by Joule heating. The SMA materials under investigation are NiMnGa and NiTi(Hf) films with tunable phase transformation temperatures. We show that Joule heating of the cantilevers generates increasing temperature gradients for decreasing cantilever size, which hampers actuation performance. In order to cope with this problem, a new method for design optimization is presented based on finite element modeling (FEM) simulations. We demonstrate that temperature homogenization can be achieved by the design of additional folded beams in the perpendicular direction to the active beam cantilevers. Thereby, power consumption can be reduced by more than 35 % and maximum deflection can be increased up to a factor of 2 depending on the cantilever geometry.
4950  https://doi.org/10.3390/iecat2020-08501$xR$3Volltext$534
4950  https://nbn-resolving.org/urn:nbn:de:gbv:8:3-2021-00039-6$xR$3Volltext$534
4961  https://macau.uni-kiel.de/receive/macau_mods_00000969
5051  500
5051  600
5550  e-beam lithography
5550  finite element modeling
5550  microactuator
5550  shape memory bimorph effect
5550  silicon technology