Investigation of the behaviour of a new miniature carbon-paraffin phase-change actuator

Abstract

This paper presents a new millimeter-sized membrane actuator utilizing the volume expansion, resulting from a phase-change composite material, induced by self-heating through the Joule effect. The composite consists of carbon particles as the conductive elements and of paraffin wax as the polymer matrix. The behavior of the actuator is experimentally characterised by measuring its external temperature, its electrical resistance and the membrane deflection. Several factors influencing these measurements are identified and briefly discussed. A detailed analysis of the experimental findings follows, so as to provide a deeper physical understanding of the observed actuator behavior, thus allowing future design and performance improvements.