A device that’s turned off doesn’t suck battery life, but it also doesn’t work. Now a low-power system that’s always on the alert can turn devices on when they are needed, saving energy in the networked internet of things.
As smartphone users know all too well, a sleeping device can still suck the life out of a battery. One solution for extending the battery life of wireless devices under development by researchers at Stanford University is to add a wake-up receiver that can turn on a shut-off device at a moment’s notice.
Amin Arbabian, assistant professor of electrical engineering, right, and graduate student Angad Rekhi demonstrate their ultrasonic wake-up receiver and the circuit boards used to test its performance. (Image credit: Arbabian Lab)
Angad Rekhi, a graduate student in the Arbabian lab at Stanford, and Amin Arbabian, assistant professor of electrical engineering, have developed a wake-up receiver that turns on a device in response to incoming ultrasonic signals – signals outside the range that humans can hear.