A thermotropic liquid crystal elastomer micro-actuator with integrated deformable micro-heater

Abstract

We present a liquid crystal elastomer (LCE) actuator with large stroke and fast reaction time. LCEs show a large macroscopic shape change when heated above the phase transition (≈120°C). Buried wafer-level fabricated micro-heaters offer optimal thermal reaction times and compact design of the actuators. A relative length change of λ = 1.28 was obtained with 320 mW power consumption. Heating the device from room temperature takes τ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rise</sub> = 19.7 s, cooling below the phase transition temperature from the fully contracted state needs τ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">fall</sub> - 5.6s. We verify that the displacement may be accurately controlled by varying electrical input power.