Thermoactuated twist in liquid crystal elastomer for temperature sensing

Abstract

This thesis explores the possibility of utilising liquid crystal elastomers (LCE) for thermal sensing applications. To measure its thermal properties, a thin film of LCE was photopolymerised in splayed nematic alignment and cut out to form a helical shape, a coil. The coil was then set within a temperature-controlled measurement compartment and observed through a camera setup as the tip of the coil twisted upon heating or cooling. Thermal sensitivity of the coil was subsequently measured and compared to other LC-based thermal sensing systems to assess the sensor’s thermal resolution. This angular change of the twist was then characterised as a function of temperature with three temperature gradients. In addition, the relaxation time of the coil was measured in constant temperature after rapid heating and cooling.