Micro-nano actuators driven by polarised light

Results on a system exhibiting all-optical actuation are reported. Clamped silicon cantilevers, coated on top with thin films of chalcogenide glasses, reversibly deflect upwards or downwards when illuminated with linearly polarised light with the electric vector of the light being respectively parallel or perpendicular to the cantilever axis. The response is strongly wavelength selective, the maximum, and fastest, response being achieved for illumination with light having a photon energy comparable to the bandgap energy of the semiconducting amorphous chalcogenide layer. This effect can form the basis of micro-opto-mechanical system devices, controlled by varying the intensity, wavelength or polarisation direction of the incident light.