Unlike electronics, simple methods for testing and characterizing internal failure modes of MEMS do not exist. For the designer, it can result in large numbers of costly prototypes. For the fabricator, it means reduced yields because common techniques such as laser trimming cannot be applied. This image shows a microfabricated accelerometer and the associated video shows its response to a 7.7 kHz electrical stimulus in slow motion. From images like these taken at multiple planes of focus, we can measure 3D motions of any part of the accelerometer with 4 nm precision.
More information is available in a recent talk .
Microfabricated accelerometers and gyroscopes must be operated in a vacuum to reduce the detrimental effects of the surrounding air. Theoretical results are then compared with experimental measurements described above. This figure and the associated video show a computer simulation of the motion of fluid in the inner ear. The dots represent water particles. The vertical structure, which represents the mechanically sensitive hair bundle of a single sensory receptor cell, is hinged to the surface from which it projects with a spring.