The Investigation of a Shape Memory Alloy Micro-Damper for MEMS Applications

Some shape memory alloys like NiTi show noticeable high damping property in pseudoelastic range. Due to its unique characteristics, a NiTi alloy is commonly used for passive damping applications, in which the energy may be dissipated by the conversion from mechanical to thermal energy. This study presents a shape memory alloy based micro-damper, which exploits the pseudoelasticity of NiTi wires for energy dissipation. The mechanical model and functional principle of the micro-damper are explained in detail. Moreover, the mechanical behavior of NiTi wires subjected to various temperatures, strain rates and strain amplitudes is observed. Resulting from those experimental results, the damping properties of the micro-damper involving secant stiffness, energy dissipation and loss factor are analyzed. The result indicates the proposed NiTi based micro-damper exhibits good energy dissipation ability, compared with conventional materials damper.