Low-temperature operation of ionic polymer metal composite actuators

Abstract

There is currently a need for actuators that will operate in low temperature environments. Ideally, the Ionic Polymer-Metal Composite (IPMC) actuator should be able to operate in a temperature range of 0 to -50 degrees Celsius. IPMC can be a useful solution for cold temperature actuation because of its soft actuation with relatively low input voltages while the base polymeric material can undergo a multiple phase transition below 0 degree Celsius. Due to the complex nature of the material, the physics become increasingly difficult to predict in a low temperature environment on account of the IPMC/s dependency upon water and/or tightly bounded cations/water for effective actuation. In this paper, we provide experimental data and an apparatus that is constructed to obtain force feedback from an IPMC sample that is placed in a subzero chamber. The electric/thermal/mechanical data for this experiment is presented and assumptions are made and explained regarding the nature of the cold temperature actuation. Also, analytical tool used is DSC to reveal the true water structures in the IPMC. It should be noted that the use of IPMC in the temperature range of -50 to 0 degree Celsius is of importance for a number of engineering applications.