Scanning Laser Vibrometer for MEMS Control Devices

摘要

This grant purchased a Scanning Laser-Doppler Vibrometer which was used for the remote measurement of the dynamic displacement of MEMS actuators. The vibrometer is capable of measuring minimum displacements of 0.25 micrometer/ s/square root Hz at a standoff distance of 2 m. The sample area can be made as small as 200 micrometer diameter and the frequency response is up to 20 kHz. The device is capable of either continuous or discrete scanning. Besides the displacement information, modal shapes can be obtained for more complicated structures. Digital and computer-graphic output is possible. Details of the equipment are given in the Appendix. The primary use is part of an existing research program that addresses flow control using quasi-static and dynamic roughness elements within a swept-wing boundary layer. The roughness actuators are spanwise distributed near the attachment line and it is important to measure the roughness height under the actual flow conditions. This equipment is also used in three other AFOSR supported research activities as well as in an undergraduate laboratory and a student project.