Polymeric Thermal Microactuator With Embedded Silicon Skeleton: Part II—Fabrication, Characterization, and Application for 2-DOF Microgripper

This paper presents the fabrication, characterization, and application of a novel silicon-polymer laterally stacked electrothermal microactuator. The actuator consists of a deep silicon skeleton structure with a thin-film aluminum heater on top and filled polymer in the trenches among the vertical silicon parts. The fabrication is based on deep reactive ion etching, aluminum sputtering, SU8 filling, and KOH etching. The actuator is 360 mum long, 125 mum wide, and 30 mum thick. It generates a large in-plane forward motion up to 9 mum at a driving voltage of 2.5 V using low power consumption and low operating temperature. A novel 2-D microgripper based on four such forward actuators is introduced. The microgripper jaws can be moved along both the x- and y-axes up to 17 and 11 mum, respectively. The microgripper can grasp a microobject with a diameter from 6 to 40 mum. In addition, the proposed design is suitable for rotation of the clamped object both clockwise and counterclockwise.