Microactuators are an essential component in microsystems and microdevices, and in applications such as pumps, valves, or switches. The properties of these materials (strain, speed, density, power) are of high interest for industrial, medical, and domestic uses. A. Sánchez-Ferrer et al. have synthesized liquid-crystalline polymers (LCPs) containing photoreactive groups in order to obtain liquid-crystalline elastomers (LCEs). Their synthetic strategy results in thin elastomeric films, which they can integrate into silicon-based microsystems. Analysis of their thermally controlled model microactuator at different voltage rates indicates that it is suitable for slow, sensitive positioning and gripping movements. On applying electrical power, the nematic-to-isotropic transition induces changes in the LCE film length causing strains of up to 150% and the capacity to move up to 400 times its own mass! /lb

The gripper in action:

A. Sanchez-Ferrer et al., Macromol. Chem. Phys. ; DOI: 10.1002/macp.200900308