LEVITATION OF UNTETHERED STRESS-ENGINEERED MICROFLYERS USING THERMOPHORETIC (KNUDSEN) FORCE

In this paper we present the theory and initial successful levitation experiments of untethered microscale structures (microflyers) using thermophoretic force. The microflyers consist of a 300 μm × 300 μm sized chassis fabricated from polycrystalline silicon using a surface micromachining process. The devices are levitated using microfabricated heaters attached to an underlying substrate. A novel in-situ masked post-release stressengineering process is used to generate a concave upwards curvature of the flyers chassis, resulting in increased pitch and roll stability during flight, take-off, and landing.