Abstract: An array of energy harvesting units is disclosed. Each unit has a flexible, elongated support with the proximate end fixedly connected to a stationary support such that the flexible beam experiences a mechanical vibration due to flow of a fluid. An active material is disposed on the flexible support that generates an electric current in response to the mechanical vibration. A coupler is provided on each energy harvesting unit such that each is connected to at least one adjacent unit. The resulting array provides an energy output that is greater than the sum of two, uncoupled units.

Abstract: A self-powered sensor is provided for fatigue monitoring and other low power requirement applications. The self-powered sensor is comprised of: a piezoelectric transducer; a non-volatile memory comprised of at least one floating gate transistor; and a current reference circuit adapted to receive a voltage signal from the piezoelectric transducer and operable to output an injection current into the non-volatile memory. The current reference circuit may employ a floating gate transistor operating in a weak-inversion mode.

Abstract: An implantable self-powered sensing system for a bone fixation device, which includes a self-powered strain sensor mountable on or in a bone fixation device, is disclosed. The sensor is capable of measuring strain in the bone fixation device by generating a strain signal in response to stresses produced thereupon. The system also includes a telemetry unit powered by the generated strain signal and in communication with the sensor. The telemetry unit is activated by the sensor when the strain signal reaches a predetermined value and then transmits the strain signal from the sensor to an external receiver. The sensing system can also include a buffer unit in communication with the sensor and the telemetry unit for collecting and storing the strain signals for transmission by the telemetry unit as a cumulative strain measurement.