For a summary and broad perspective of our work that is less technical, please read our feature in the ACM XRDS Student Magazine titled “Batteries Not Included”
We are quickly heading towards a trillion device Internet-of-Things (IoT), buffered by self-fulfilling prophecies and promises from industry leaders like ARM, Intel, and NVIDIA, and pushed forward by the march towards automation of numerous industries. This explosion of devices have led many to explore alternative designs that reduce the ecological footprint, the electronic waste, caused by disposable and fast obsolescing computing devices. Battery-free devices that harvest energy from sunlight, thermal gradients, and RF sources have risen as a popular alternative in the research (and now consumer) realms to mitigate the consequences of a trillion battery powered devices that need constant charging and replacement. This emergence of battery-free mobile computing has sparked new approaches to computing and radical systems, like a battery-free cell phone, battery-free Nintendo Game Boy developed in our lab, and novel programming, runtime, and architecture level techniques to provide reliable computation and sensing despite the volatility of energy harvesting and in many cases frequent power failures.
The large majority of these battery-free systems are passive, or invisible. They are used for large scale sensing of infrastructure, farms, or in places where long term sensing is needed with minimal human involvement, like monitoring fragile relics of antiquity Sometimes they are even shot into low earth orbit. These passive devices are not the limit of what battery-free and energy harvesting devices can accomplish. Indeed, of the trillions of future devices in this battery-free IoT, many 100s of millions may be interactive, for example labels on food items that react and change to user presence or handling, engaging and wire free museum displays for children, to every day items like toys, game consoles, smart watches, coffee mugs, and pill bottles.
Our ongoing research explores new ways to build these devices, starting with the worlds first battery-free Nintendo Game Boy.