A team from the Northeastern University has developed a sensor that requires almost no power to work and operate. Made for the US Department of Defense's Darpa (Defense Advanced Research Projects Agency) for its N-Zero programme, it can detect and read infra red (IR) light and frequencies.

The sensor will reportedly require no external battery power to operate, consuming "zero standby power" until it detects IR radiation. When it encounters IR wavelengths, it will prompt mechanical movements within the sensor that will heat it and confirm that there is a source of such light in its vicinity, using plasmonically enhanced micromechanical photoswitches (PMPs) — switches made with materials that can covert light to electricity — according to a paper published by Nature- Nanotechnology.

These sensors have been built so as to react to specific wavelengths of IR light, so ambient IR will not be picked up. These qualities allow it to be placed anywhere, including in places that do not have access to stored power or solar energy for it to work.

Another advantage of using zero-power sensors is that it can reduce the cost of deployment, installation, and maintenance, besides extending the life of sensors, simply because they are not switched on and consuming energy constantly, notes the publication.

"The sensors remain dormant with near-zero power consumption until awakened by a specific physical signature associated with an event of interest," reads the publication.

The report points out that because of this feature, there will only be specific data points recorded as there will be no need for the sensors to constantly monitor its surroundings.

IR signatures of exhaust fumes, for example, are different between vehicles or different sizes, they are even different based on the type of fuel they use, reports Futurism. That means a set of sensors could potentially not only read that a vehicle is nearby, but also actually tell if it is a car, a truck, or even an aeroplane, based on just the IR wavelengths emitted. This is possible because fuels produce different emissions based on their chemical compounds, says the report.

"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," reads the published paper, quoted by the report.

Considering the project is for a defence agency, it is not clear if these sensors will be used in civilian operations in future, or when and where it will be used by Darpa.