A Battery-Less Sensor Concept Outputting Perceivable Signal Demonstrated With an Accelerometer

A stringent battery-less sensor concept stipulating the entire operation of sensing and result indication to be driven solely by the sensing element without any additional power source has been proposed and implemented with a completely self-powered accelerometer as an example. The operation involves energy harnessing of the vibration into electrical charge with a piezoelectric cantilever, accumulating the charge and then releasing it into an indicator device via an ultra-sharp switch. Deemed as an unprecedented accelerometer feature, the acceleration information at a single frequency is quantitatively indicated by the period of the pulsed light or sound from the self-powered indicator device, which is directly perceivable and comprehensible to the user. This letter realizes an energy autonomous sensor system as highly desired by the end users.