Monolithic SUEX Flapping Wing Mechanisms for Pico Air Vehicle Applications

This paper develops a simple flapping wing mechanism fabricated monolithically from an epoxy-based negative photoresist (SUEX) dry film. The developed fabrication process has fewer steps compared to other methods, does not use precious metals, and greatly reduces processing time and cost. It simultaneously defines the pico air vehicle (PAV) airframe, compliant flapping mechanism, and artificial insect wing using photolithography. Using this process, we designed and fabricated the LionFly, a flapping wing mechanism actuated by a PZT-5H bimorph actuator. Rapid prototypes were fabricated with precisely defined features and material properties and geometry that are similar to insects. We present the fabrication process and characterization of SUEX and show that flexure thickness can be controlled by 310 nm UV dose. Static and dynamic modeling of the LionFly have excellent agreement with experimental data. Performance from multiple prototypes shows devices with resonance frequency of 49.13 $\pm$ 1.43 Hz and up to 75 $^{ \circ}$ peak to peak flapping angle demonstrating applicability of the fabrication process for flapping wing PAV applications. $\hfill$ [2012-0168]