High-cycle fatigue and strengthening in polycrystalline silicon

The reliability of MEMS-based sensors for automotive applications critically depends on their high-cycle load-bearing capacity. To investigate the influence of high-frequency cyclic loading on mechanical properties of polycrystalline silicon, a statistically based investigation with the use of novel rotational specimens (90 kHz) has been conduced. Either fatigue fracture (above 3 GPa) or strengthening of the material at cyclic loading below 3 GPa has been observed.