Dynamic strain distribution sensor sheet based on ultra-thin PZT/SI array on flexible substrate for bridge monitoring wireless sensor network

We have developed dynamic strain distribution sensor sheet using flexible printed circuit (FPC) substrate with 5×5 MEMS-based ultra-thin PZT/Si array. The sensor sheets equipped with signal processing and wireless communication module were attached on the stainless plate as test body and the partly cracked concrete piers of actual bridge. In both case, the output voltage from the PZT/Si on the crack is 3-5 times larger than that on the smooth surface. The resultant mapped images of dynamic strain distribution have shown anomaly at the cracked site.