On the improvement of the dynamic performance of dielectric elastomer actuators for active compression

Dielectric elastomer actuators have been considered for an increasing number of applications due to their desirable characteristics of low weight, high strain outputs and favourable material costs. The present work describes the use of a dielectric elastomer actuator in conjunction with a belt mechanism to apply cyclic active compression. The belt mechanism helps convert the stress relaxation upon the voltage application to the dielectric elastomer actuator to a compressive force. Testing is conducted using multi-layered silicone–based dielectric elastomer actuators. A novel method of dynamically charging dielectric elastomer actuators through manipulating the input signal shape, termed the hold method, is introduced. Using this method, cyclic actuation strain output can be increased by 24% with insignificant change in actuation output curve shape. Furthermore, the effect of pre-stretch ratios on the output force amplitudes is characterized. The optimized hold time parameters obtained through cyclic dielectric elastomer force and strain are utilized for active compression physiological testing and a pressure gradient of 10 mmHg is achieved.