Towards Microscale Flight: Fabrication, Stability Analysis, and Initial Flight Experiments for 300 $\mu {\rm m} \times \,$ 300 $\mu {\rm m} \times \,$1.5 $\mu {\rm m}$ Sized Untethered MEMS Microfliers

This paper presents modeling, designs, and initial experimental results demonstrating successful untethered microscale flight of stress-engineered microscale structures propelled by thermal forces. These MEMS Microfliers are 300 $\mu {\rm m} \times \,$300 $\mu {\rm m} \times \,$1.5 $\mu {\rm m}$ in size and are fabricated out of polycrystalline silicon using a surface micromachining process. A concave chassis, created using a novel in-situ masked post-release stress-engineering process, promotes static in-flight stability. High-speed optical micrography was used to capture image sequences of their flight, and this imagery was subsequently used to analyze their mid-flight performance. Our analysis, combined with finite element modeling (FEM) confirms stable flight of the microfliers within the thermal gradient above the heaters. This novel microscale flying platform presented in this paper may pave the way for new types of aerial microrobots.