Flexible pneumatic twisting actuators and their application to tilting micromirrors

Compliant pneumatic actuators have recently attracted the interests of the robotics community, especially for soft robotic applications where large strokes are needed in delicate environments. To date, these actuators have demonstrated the ability to generate contracting, expanding and bending strokes. This paper introduces a new actuator design that complements the existing actuators by generating twisting deformations upon pressurization. A fabrication process is developed that uses accessible PDMS soft lithography techniques. With this process, prototype actuators with a width of 7 mm and a thickness of 0.65 mm have been made that achieved a twisting rotation of 6.5°/mm actuator length at a pressure of 178 kPa. This paper also presents the integration of four twisting actuators into a 2 DOF tilting mirror platform which is capable of deflecting a mirror over 25° at a pressure of 231 kPa.