World’s Smallest Temperature Sensor Runs without any Battery

In a world where we assume that Amazon’s Echo paired with IFTTT is the future of technology, researchers from the Netherlands have created the smallest temperature sensor ever built by man. The sensor runs on radio waves and can, pretty much, run forever. This is a great fact since battery technology has not shrunk to a great degree in the past decade.

The sensor was created by a team of researchers at Eindhoven University of Technology and is powered by radio waves emitted by a wireless network nearby. The idea was developed by Hao Gao, a researcher at Eindhoven University of Technology, who chose the idea as his thesis for his PhD. His paper was titled – “Fully Integrated Ultra-Low Power mm-Wave Wireless Sensor Design Methods”.

Measuring almost 0.08” sideways and weighing about 1.6mg (equivalent to a grain of sand), the temperature sensor can power itself and recharge at the same time using an antenna. The only drawback is that it has to be within 2.5cm of a special router used to power the sensor.

The sensor can be painted into walls and can be submersed beneath plastic or concrete. It has the ability to monitor light, movement, temperature and humidity. Because it needs virtually no power source on the device itself, the sensor can be a viable asset in the development and deployment of smart & intelligent buildings of the future.

The sensor works by connecting to the router through an antenna. Once reaching the energy threshold, it powers on, measures the temperature and sends a specific frequency signal to the router. The frequency transmitted is different for every temperature reading.

This project, called PREMISS, is funded by the STW technology foundation. Organizations involved in the research were Mixed-Signal Microelectronics group, TU/e groups Electromagnetics and Signal Processing Systems and the Center of Wireless Technology.

Mass production of the device would result in each sensor costing about 20 cents each. Researchers expect to increase the range of the sensor to 5 meters within a year. If this happens, a network of these sensors can be used to construct a temperature map of an entire building in the future.

Eindhoven University of Technology says, “The sensor stores that energy and, once there is enough, the sensor switches on, measures the temperature and sends a signal to the router. The smart buildings of the future will be full of sensors that will respond to the residents’ every need, and will be as sustainable as possible. Like heating and lighting that only switches on when someone is in the room.”