New and Emerging Energy Sources for Implantable Wireless Microdevices

In this paper, we review new and emerging energy sources for wireless implantable microdevices. After a brief historical background, we review the developments in power sources in the decades following the pioneering works of Zworykin and Mackay in the late 1950s. These include deployment of lithium batteries and inductive powering in the 1970s, which resulted in significant growth and commercialization of implantable medical devices, such as cardiac pacemakers and cochlear implants. Recent research in nanoscale materials for energy generation has created intriguing possibilities for next generation implantable power sources in the form of flexible and biodegradable batteries and supercapacitors. In addition, energy harvesting/remote powering from various environmental physical and chemical sources within the body utilizing nanoscale materials can also offer unique possibilities for autonomous implantable microscale and nanoscale devices.