Piezoelectric energy harvesters for biomedical applications

Recently, implantable medical electronics (IMEs) have become essential for extending patient's lives. Extending the lifespan of these devices has in turn become a main challenge for their development; thus, current research efforts on this topic are focusing on their power sources (e.g., generation of energy by body activity). In this respect, piezoelectric energy harvesters (PEHs) are ideal candidates for the capture and subsequnt conversion of biomechanical energy into electric energy to operate IMEs (e.g., energies created through muscle relaxation and contraction, body movement, blood circulation, lung motion, and cardiac motion). This paper reviews the recent developments in PEHs and associated biomedical devices. The materials and fabrication processes needed for the development of PEHs are also discussed along with their biomedical applications (e.g., cardiac pacemaker, active pressure sensors, direct stimulation of tissue, and living cells). The present limitation and future prospects of PEH technology are discussed finally.