Tuesday, December 26, 2006

US Patent 7152474 - MEMS Asymmetry Self-test


Microdevices such as accelerometers may exhibit improper operation over time due to asymmetries of manufacture or environmental effects. Due to the small size of such devices it is difficult to provide external means to reliably detect such improper operation. This patent from Carnegie Mellon University proposes building in an intrinsic sensing system to detect asymmetries in the microdevice to easily provide data whether the microdevice needs to be replaced or alternatively to provide self correcting signals for driving the microdevice. Claim 1 reads:

1. In a MEMS device, the improvement comprising: a plurality of sensors electrically isolated from one another and positioned about an axis of symmetry to produce signals of substantially identical characteristics; and circuitry responsive to said plurality of sensors for comparing said signals produced by said plurality of sensors to identify asymmetries in said MEMS device.