Dutch researchers have created a tiny (2 millimetres) wireless temperature sensor which doesn’t need a battery to power it. Using radio waves emitted by the sensors wireless router, the sensor can collect enough energy to power up then start transmitting the temperature back to the wireless router. Currently the minute sensor needs to be within 2.5 centimetres (1 inch) of the wireless router which isn’t useful but the researchers are hoping to get the distance up to 1 meter (3 feet) within a year and ultimately achieve 5 meters. Additionally, the cost of an individual sensor would be around 20 cents.
Sensors powered this way could help manage smart buildings to turn on lights when people enter a room or to efficiently maintain air-conditioning temperatures.