Disclosed is a radiation detector, comprising a chamber or cavity that produces charge carriers when radiation is incident thereon. The chamber is defined in part by a deformable plate along one side of the chamber or cavity; and a rigid plate spaced and electrically insulated from the deformable plate. A charging voltage source is present for applying a voltage to the deformable plate; such that wherein the deformable plate is attracted toward the rigid plate by electrostatic forces when charged by the charging voltage source, and moves away from the rigid plate when charge carriers produced in the chamber or cavity by incident radiation reduce the electrostatic forces between the deformable and rigid plates.