Microfabrication of hybrid structure composed of rigid silicon and flexible PI membranes

Abstract

The authors have designed and microfabricated millimetre-scale wing-shaped hybrid microstructures composed of rigid structures of single crystal silicon (SCS) substrates and flexible polyimide (PI) membranes. The wing-shaped microstructures mimicking insect flapping flight have been newly designed using a fluid-structure interaction analysis, and the hybrid microstructures based on the design method have been successfully microfabricated using a simple process flow with SCS substrates coated with PI membranes. Shape of the SCS parts in the hybrid microstructures have been successfully fabricated using deep reactive ion etching of the SCS substrate with small etching rate, and the wing plates of PI membranes have been prepared with the photolithography and the curing processes. The flexibility of the PI membranes of the fabricated hybrid microstructures was also confirmed using the bending test of the PI membranes.