Piezoelectrically Actuated Four-Bar Mechanism with Two Flexible Links for Micromechanical Flying Insect Thorax

In this paper, a piezoelectrically actuated four-bar mechanism with two flexible links is proposed to be used in a micromechanical flying insect robot wing thorax for stroke amplification. PZT-5H and PZN-PT based unimorph actuators are utilized at the input link of the four-bar for a compact and light weight thorax transmission mechanism. The kinematics and dynamics of the proposed wing structure with two parallel fourbar mechanisms are analyzed, optimal four-bar link size selection method is introduced, and quasi-static forces generated at the wing are computed for evaluating the feasibility of the design. Using laser micro-machining and folding techniques, prototype four-bar structures are constructed. In the experiments, for a 10×1×0.12 mm PZT-5H actuator based four-bar mechanism, stroke amplification of around 20 − 25 is held, and an attached polyester wing is resonated at 29 Hz with around 90 flapping motion. These results match closely with the predicted theoretical values.