The scaling of strength in the design of high-power MEMS structures

The prediction of the strength of complicated structures based on material test data is important for high-power density microelectromechanical systems. Probalistic analysis is used to predict the strength of pressure-tested microfabricated silicon structures from simpler test specimens. The predictions are found to be non-conservative. This is probably due to interactions between the etching process and the structural geometry, which changes the flaw distribution between the two statistical populations. In both cases secondary smoothing etches recover the strength.