Magnetic and Piezoelectric Energy Harvesting for Autonomous Bionic Systems

Autonomous bionic systems are ultra-low power systems with low data rate operation. Most healthcare bionic systems that are implantable in the human body utilize MEMS technology as well as different biomedical signal processing techniques. The conventional solution of powering such systems using batteries is not practical as battery charging or replacement may not be feasible or desirable. As such, the need to explore new solutions in order to increase lifetime and achieve autonomous operation is fueling the energy scavenging research. This article presents a study of magnetic and piezoelectric energy harvesting and their suitability for autonomous bionic systems that incorporate biomedical signal processing in their functionality. A study of magnetoelectric-piezoelectric transducers used in biomedical systems is presented. Our study shows that integrating magnetostriction and piezoelectric effects in a single transducer significantly increases the harvested voltage by 2× and increases the total efficiency of the harvesting system. As such, integrating magnetostrictive and piezoelectric materials in energy harvesters provides a promising solution for autonomous bionic systems with biomedical signal processing capability.