Revolutionary Sensor Consumes Zero Power

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Sensors for various purposes require power to operate, whether it is from batteries, biofuel, or sunlight. Along with power consumption are problems with sensors always being on, such as lifetime and maintenance. These issues are especially apparent when sensors are placed in remote areas or underground.

Recently, a research team from Northeastern University developed a new type of sensor that has overcome these limitations by consuming near-zero power when not acted upon by the desired sensing range. The sensor is effectively asleep, while capable of sensing events at the same time.

Led by Matteo Rinaldi, an associate professor of electrical and computer engineering, the researchers developed the new smart sensor for the Defense Advanced Research Projects Agency (DARPA) for the N-Zero program, though it has a myriad of applications outside military use.

According to allaboutcircuits.com, the technology is based on the use of plasmonic nanostructures. These plasmonic nanostructures are nano-sized metal patches that are used as plasmonic devices in that they react to a specific range of light to oscillate and expand. In their research, the team tuned their nanostructures to take the energy of a distinct wavelength of infrared light. This caused the metal patches on metal switches to absorb heat, bending the switch to create an electrical connection.

While there was no infrared signal, the devices consumed no power. When there was a signal, however, the device was powered by the infrared light. Hence, DARPA calls the sensors “dormant” until activated.

“The technology features multiple sensing elements—each tuned to absorb a specific IR wavelength,” said Troy Olsson, who manages the sensor program at DARPA.

Impressively, the sensor can also be tuned to sense a myriad of very specific events. One specific test was run on the exhaust coming from a car. The fumes have a specific infrared frequency which the team was able to analyze and target. They then proceeded to design the sensor with patterned gold patches that would absorb the target infrared radiation causing the metal switch to bend, forcing the contacts together and ultimately producing a signal.