A computational study of radiometric phenomena for powering microactuators with unlimited displacements and large available forces

Microactuators utilizing radiometric forces are described. A candidate actuator formed from a series of vanes mounted on an armature positioned between two closely spaced bounding surfaces was assumed for the study. Controlled heating of the vanes or portions of the bounding surfaces generates a rarefied gas dynamic force leading to a displacement of the vanes and armature. Parametric direct simulation Monte Carlo calculations have been obtained to estimate the performance of a nominal actuator and assess its sensitivity to rarefaction (controlled by a combination of actuator size and ambient gas pressure), vane configuration (inclination and placement), and location of energy input. Results show that the proposed class of actuators can provide relatively large available forces and, at least in principle, unlimited, reversible displacements.