A surgical stapling system including a shaft assembly transmits actuation motions from an actuator and an end effector compresses and staples tissue. The end effector comprises an elongated channel; an anvil having a staple forming surface is moveable relative to the elongated channel between an open position and a closed position; and a staple cartridge removably positioned within the elongated channel. The staple cartridge comprises a body having a tissue contacting surface in a confronting relationship with the staple forming surface; a plurality of staple drivers within the cartridge body each supporting a staple; and a tissue thickness compensator positionable between the anvil and the cartridge, the tissue thickness compensator is captured by the staples and assumes different compressed heights within the different staples. The tissue compensator comprises first conductive elements. The system determines properties of tissue compressed between the anvil and the cartridge.