A team of researchers at Northeastern University have developed a new sensor powered by the very infrared energy it's designed to detect. The device, which was commissioned as part of DARPA's Near Zero Power RF and Sensor Operation (N-ZERO) program, consumes zero standby power until it senses infrared (IR) wavelengths.
Energy from this source heats the sensing elements, prompting mechanical movements that close a circuit and beam out signals confirming that the IR wavelengths have been detected. A grid of nanoscale patches forms a logic circuit, with each patch being constructed with specific dimensions corresponding only to the wavelengths it's designed to detect.
Consequently, the circuit can be altered to analyze various IR spectra. It's possible for the sensor to simply detect IR wavelengths in its surroundings, or determine whether the energy that has activated it came from a fire, a person, or some other source.
Wake Me When I'm Needed
A sensor like this is advantageous because it can be placed absolutely anywhere, without the need for a power supply, or access to solar energy. Such versatility sounds like wetware of William Gibson's Neuromancer, so it's no surprise it's fallen into DARPA's cross-hairs.
The sensor is capable of detecting vehicles emitting energy via the IR spectra produced by exhaust fumes. Furthermore, since engines that burn gasoline or diesel fuels produce emissions made up of different chemical compounds, it's able to detect whether the vehicle that it's "seeing" is a truck, a car, or an aircraft.
"The capability of consuming power only when useful information is present will result in nearly unlimited duration of operation for unattended sensors deployed to detect infrequent but time-critical events," states the paper, which was published this week in Nature Nanotechnology.