Researchers at Eindhoven University of Technology (TU/e) have developed the world’s tinniest wireless temperature sensor powered by radio waves.
The sensor which was conceived and demonstrated by lead researcher Hao Gao, measures just 2 square millimeters and weighs 1.6 milligram, equivalent to a grain of sand.
The sensor has a specifically developed router with an antenna that sends radio waves to power the device. The energy transfer is accurately targeted at the sensor, consequently reducing the energy consumption.
Once the sensor has absorbed enough energy, it powers on and measures the surrounding temperature. The sensor then sends a signal to the router which has a distinct frequency. The router in turn deduces the temperature value from this signal frequency.
The sensor is based on 65-nm CMOS technology and can be embedded in a layer of paint or cement. Moreover the sensor is wireless and needs no batteries, making it an ideal sensor technology to design smart homes.
At present, the sensor is limited to a working range of just an inch. The researchers hope to expand its reach to 40 inches within the next year, and further still in the future.
The researchers contend that the same technology can be incorporated into other wireless sensors that measure movement, light and humidity or payment systems and identification tools.
“They won’t be expensive either: mass production will keep the cost of a sensor down to around 20 cents,” said research partner Peter Baltus.
Image credits: Bart van Overbeeke / Eindhoven University of Technology