A tire monitor includes a first device (300) having at least one piezoelectric matrix element (404), and a first sensing layer (410) that includes at least one rectifier (106) and a processor element (110). The first device (300) is capable of sensing a deflection (u) in a layer of material, and is capable of processing the sensed deflection. The first device (300) is capable of wirelessly transmitting an indication (116) on a condition of the material.