Piezoelectric energy harvesting and ultra-low-power management circuits for medical devices
Noora Almarri, Jinke Chang, Wenhui Song, Dai Jiang, Andreas Demosthenous
Abstract
Piezoelectric energy harvesting enables the development of sustainable, batteryless medical devices , powered by microwatts level energy transduction and low frequency body area motions. To optimize the energy harvested by piezoelectric materials , energy harvesting circuits are needed to maximize extraction suitable for powering medical devices. This paper reviews the state-of-the-art energy harvesting and management circuits for self-powered implantable and wearable medical devices. Both laboratory and commercially available self-powered piezoelectric implantable and wearable systems are described. Power consumption , power transfer efficiency, energy stability, and system reliability of various piezoelectric materials and power harvesting and management circuits are compared and analyzed. The paper provides a comprehensive review of the many state-of-the-art integrated ultra-low-power management circuits that can significantly enhance the device power output extracted by up to tenfold. It includes power harvesting interface, dc-dc converters, maximum power point tracking , and cold start-up circuits. Finally, guidelines are presented for the choice of optimum designs to address the limitations and provide medical devices with reliable and highly efficient power harvesting at nanowatts level.