Measurement of the mechanical power of an EAP based pump

Electroactive polymers (EAP) are used in many biotechnological devices as artificial muscles. The main advantage of this technology is the large deformation (several millimeters) of the membrane. In this paper, the mechanical power of an EAP based pump is calculated. The EAP membrane consists of a 0.3mm thick 3M^TM VHB^TM tape and pre-stretched 4.4 times. The pump effect is obtained through a specific shape of the EAP. Using this form and compelling the membrane, a mechanical power is created when the EAP is activated. The main problem to get the useful power, based on the electrical energy, is to measure very low currents. A test bench is proposed to measure the ratio between the mechanical energy won by a mass during a cycle of the pump and the source energy. In order to get the energy of an EAP, complex model based on springs and analytical definitions are proposed. The measurements are finally compared with these latter.