The present invention provides an RFID-based
torque sensor that can be used to quickly monitor
off the shelf fasteners including fasteners that are used in expensive satellites or other uses where
fastener failure can be very costly. In one embodiment, an antenna, RFID ring and spring comprise a sensor tag that can be interrogated with an interrogation
signal produced by an interrogator device. When sufficient torque is applied to the
fastener, an RFID circuit is connected, and produces a
radio frequency (RF)
signal that can be read by the interrogator. In one embodiment, the RFID circuit does not transmit when the spring member is not compressed, thereby indicating insufficient tensioning of the
fastener. The present invention offers the ability to remotely, quickly, and inexpensively verify that any number of fasteners are torqued properly upon initial installation. Where applicable, the present invention allows low cost monitoring over the life of the fastener.