Systematic approach to development of pressure sensors using dielectric electro-active polymer membranes

Abstract

Dielectric electro-active polymers (DEAPs) have become attractive materials for various actuation and sensing applications due to their high energy and power density, high efficiency, light weight, and fast response speed. However, commercial development has been hindered due to a variety of constraints such as reliability, non-linear behavior, cost of driving electronics, and form factor requirements. This paper presents the systematic development from laboratory concept to commercial readiness of a novel pressure sensing system using a DEAP membrane. The pressure sensing system was designed for in-line pressure measurements for low pressure applications such as health systems monitoring. A first generation sensor was designed, built and tested with a focus on the qualitative capabilities of EAP membranes as sensors. Experimental measurements were conducted that demonstrated the capability of the sensor to output a voltage signal proportional to a changing pressure. Several undesirable characteristics were observed during these initial tests such as strong hysteresis, non-linearity, very limited pressure range, and low fatigue life. A second generation prototype was then designed to remove or compensate for these undesirable characteristics. This prototype was then built and tested. The new design showed an almost complete removal of hysteretic non-linear effects and was capable of operating at 10 × the pressure range of the initial generation. This new design is the framework for a novel DEAP based pressure sensor ready for commercial applications.