Tiny Wake-up Receivers from Draper Could Extend Battery Life of Sensors

Warfighters rely on sensors in war zones that provide critical information. Sensors watch over the roads that U.S. armed forces travel on by detecting when adversaries bury improvised explosive devices. To constantly monitor battlefield conditions, sensors are always “on” as they need to detect vibration, light, sound or other signals for situational awareness and to inform tactical planning and action. With their current dependence on small batteries, they tend to have short lives and this can put soldiers at risk by forcing them to expose themselves to ambush attacks while changing sensor batteries.

Draper has addressed this challenge by developing a sensor that awakens only in the presence of target acoustic signals - and thus requires far less power to operate. In a radical redesign, Draper engineers found they could reduce the sensor’s standby power needs to near-zero if they built a MEMS (microelectromechanical system) sensor.

Jonathan Bernstein, a microelectromechanical engineer at Draper has designed a zero-power acoustic wake-up switch actuated by environmental sounds that will enable sensor systems to last for years, limited only by battery discharge rates. A paper on the Draper’s new sensor has been submitted to the Journal of Microelectromechanical Systems. Their discovery could be useful for extending battery life by conserving energy and reducing drain, a beneficial feature for both internet of things devices and unattended ground sensors.

The current research into MEMS, which was funded by the Defense Advanced Research Projects Agency (DARPA) for its N-Zero Program, is part of Draper’s materials engineering and microfabrication portfolio. Draper develops sensors for energy, transportation, defense and cybersecurity, and excels at developing extremely small sensor systems with surprising sensitivity and resolution that are cost-effective and thus easier to distribute widely. Draper facilities in Cambridge include a microfabrication center, MEMS facility, polymer fabrication, precision machine shop and a Center for Additive Manufacturing.