Northwestern University researcher Josiah Hester is developing an array sustainable alternative power sources that could replace batteries—and eliminate or reduce the many negative environmental impacts of battery use. Hester’s field is called “intermittent computing,” and he builds ultra-low power devices—including a prototype batteryless Gameboy powered by the game’s button presses plus solar energy. His lab’s work has applications far beyond video games, including medical devices embedded in the human body and sensors in roadway pavement that monitor traffic and are powered by the vibrations of cars passing above.