As a student at North Carolina State University, I performed research in Dr. Seelecke’s Adaptive Structures Lab. During this time, my focus was working with Dielectric Electro-Active Polymers (DEAPs). DEAPs are thin, stretchable capacitors that can be used as either actuators or sensors. By applying a high electric field, the shape and stiffness of the DEAP is changed. These mechanical changes can be channeled into actuation movement for applications such as pumping fluids. Conversely, stretching or pressing the DEAP changes its shape and also its capacitance. These changes in electrical properties allow DEAPs to be used as strain or pressure sensors.
Conventionally when using a DEAP as an actuator, a linear spring is used as a bias force. This bias force creates and oscillating motion as the stiffness of the DEAP is varied by an applied electric field. Shown in the bottom left is a system I designed and prototyped to couple the DEAP to a negative-rate bias spring (NBS). The NBS has nonlinear stiffness characteristics that are tuned to increase the stroke of the DEAP. This work was continued by Micah Hodgins and published here. Shown in the bottom right, is a testing station that I designed for characterizing DEAP strain sensors.