|M.Sc Student||Ofer Rozen|
|Subject||Design, Manufacturing and Characterization of Micro-scale|
|Department||Department of Aerospace Engineering||Supervisor||Research Professor E Weihs Daniel|
|Full Thesis text|
The design, fabrication, and characterization of millimeter-scale flapping wings are presented. The displacement of the wings was studied, and its piezoelectric cantilever actuators were characterized.
The wing design presented below represents the smallest limits of wings found in nature, with half-wing span of 1 mm and thickness of about 2 ?m. The wings were hexagonal, coffin-shaped, and this design was intended to optimize the force generated while using a permeable membrane.
The wings were manufactured from silicon, using a combination of both surface and bulk micromachining. These methods are state-of-the-art in micro-electro-mechanical system (MEMS) technology, and were tailored to the specific design.
The wing flapping motion was generated using two unimorph lead-zirconium titanate (PZT) cantilevers, fabricated using silicon surface micromachining technology. PZT actuators require a poling process after their shaping in order to exploit the piezoelectric effect and this process was studied.
Five wing configurations were fabricated in order to study the effect of differently shaped actuators on the displacement. The possible effects of permeable membrane wings on the wing movement and force generation were also examined.
The wing testing device included two quarter Wheatstone bridges made of highly doped polysilicon piezoresistors. It was assumed that such a feature would allow comparison of the forces generated at different conditions.
Dynamic measurement by a scanning vibrometer showed that the wings resonated at 1400-1700 Hz. The measured peak-to-peak displacement was up to 350 ?m when a 5 V amplitude actuation voltage was applied.