Power Optimization of TiNiHf/Si Shape Memory Microactuators

We present a novel design approach for the power optimization of cantilever-based shape memory alloy (SMA)/Si bimorph microactuators as well their microfabrication and in situ characterization. A major concern upon miniaturization SMA/Si conventional double-beam cantilever designs is that direct Joule heating generates large size-dependent temperature gradient along length cantilevers, which significantly enhances critical electrical required to complete phase transformation. demonstrate this disadvantage can be mitigated by finite element simulation-assisted additional folded beams perpendicular direction active beams, resulting homogenization. This investigated TiNiHf/Si with film thickness ratio 440 nm/2 µm, beam 75–100 µm widths 3–5 µm. Temperature-homogenized show reduction consumption up 48% compared design.