Abstract: The structural style of steel flexure hinge is applied to design of silicon micromachining structures. Polysilicon thin film flexure hinges and the on line testing device are fabricated using surface micromachining process, and the thickness of structure layer is 2 mm. Character of polysilicon thin film flexure hinge is researched and tested. Take right circular polysilicon thin film flexure hinge as an example, the rotational stiffness calculated using the macro theory is 8 N·mm/rad and the tested result is 120 N·mm/rad. Through theory analysis and measurements, it is found that the macroscopic machine model of flexure hinge could not be applied for the design of micromachining thin film flexure hinge properly because of the size-effect. According to experimental data, the formula used in macroscopic machine is modified to meet the design and calculation of micromachining thin film flexure hinge.

Key words: MEMS, Micromachine, Polysilicon, Right circular hinge, Thin film Key words: Flexure hinge