The bimorph thermal actuator

characterized by its simple structure

large driving force

and capacity to produce out-of-plane displacement

plays a pivotal role in MEMS actuators.In this paper

bimorph materials and thickness ratio for achieving the optimal performance are ascertained by drawing upon the concepts of expansion strength and the Timoshenko isothermal bimorph model.Based on mature MEMS micro-nano fabrication process

a dry etching technique is employed to release the bimorph cantilever beams

the corrosion and adhesion issues associated with wet etching are circumvented

SiO

2

/Al bimorph thermal actuator with 18μm linewidth is fabricated.Test result demon

strates that this actuator can yield a 140μm vertical out-of-plane displacement at 100.8℃

with an unit temperature-induced displacement reaching 1.89μm·K

-1

exhibiting strong concordance with simulation results.Transient simulation research using multiphysics field finite element simulation software reveals that this micro-bimorph thermal actuator has fast response speed(5~6ms).