A piezoelectric sensor comprises a support structure, a channel extending through the support structure, a sensing material stack coupled to the support structure and extending over the channel, and a filler material disposed within the channel and over the sensing material stack. The sensing material stack comprises an structural layer, a first electrode layer disposed on the structural layer, a piezoelectric material disposed in a piezoelectric layer on the first electrode, and a second electrode disposed on the piezoelectric layer opposite the first electrode layer.