Displacement measurement of a thermally actuated polymer micro robotic gripper using the optical focus method

With the maturing design of micro electrical mechanism systems, the metrology for MEMS is becoming the hot research in the micro system technology. In this paper, we used the sum-modified-Laplacian (SML) focus measure and depth estimation method to measure the tip deflection of a thermally actuated polymer micro robotic actuator. Twenty-three under-water images of the micro actuator working at the temperature of 42°C have been used to illustrate the idea of measuring the tip deflection using optical focusing method. The results showed in the paper can be used to metrology MEMS. By optical focus method, we can measure the tip defection, which can act as a feedback input to the actuator. So, an accurate control of the motion of actuator can be achieved