Rotary actuators based on pneumatically-driven elastomeric structures

This thesis describes a unique mechanism – a soft rotary actuator – based on peristaltic motion and large strain of inflatable elastomeric materials, which consists of an inflatable stator paired with a rotor. Timed inflation and deflation of the air-filled bladders in the stators enable controllable rotational speed of the rotor (~18 RPM). With two configurations (Type 1 and Type 2), this rotary actuator is capable of having either an internal rotor for winch- or join-like applications or an external rotor that can serve as a wheel. Fabrication of these actuators employs the use of 3D-printed molds and meso- scale soft lithography. Characterizations of these two types of actuators (speed, torque, and power), along with demonstrations, provide a baseline for potential applications in locomotion and transportation of payloads. A squishy, four-wheeled vehicle enabled by Type 2 actuators travels at a speed of 3.7 cm/s, negotiates irregular terrain, and endures mechanical impact from a drop 7 times its height. This class of rotary actuators extends the potential functionality of soft robotic systems by providing torque without requiring the bending or twisting of tubing that provides pneumatic power.M.S.Includes bibliographical referencesby Xiangyu Gon