For designers of connected objects, the power supply poses an acute problem. For many consumer products, one can rely on the user to change the battery time to time, but in B2B, the problem of power supply of the connected sensors arises when the deployment of sensor networks. Often, the sensor’s lifetime depends solely on the talent of the designer to limit the power consumption of electronics and household battery. Researchers from the Sensor Systems Lab at the University of Washington offer to fetch the necessary energy to connected objects … in the oven.
The challenge is to extract enough energy ambient WiFi waves
The title recently published by the Sensor Systems Lab laboratory team research paper speaks for itself: “Powering the Next Billion Devices with Wi Fi “, ie power the next billion devices. Specialist wireless power devices, these researchers are trying notament to extract enough energy waves where we constantly bathe. They are particularly developed devices to take (some) of energy from the waves emitted by the transmitters of television. The researchers say that, coupled with a battery or a supercapacitor, the antenna and the device must be capable enough energy sensor throughout the day to allow a sensor to transmit its data. Available energy is extremely low and we had to move from theory to practice.
It’s done. These have demonstrated that they called PoWiFi is a viable solution for supplying a temperature sensor or a photo sensor, charge a battery. The researchers prepared their mounts at the home of 6 families in town. The sensors have actually been powered by the Internet router used by people without the wireless performance is not affected, except in a case where the wireless router was used in low-end model. A particular image have been transmitted by the camera on the network at regular intervals. The sensor operates on 2.4 V and consumes 60 mW, enabling the device to operate without even including battery.
The researchers demonstrated that their approach actually works in real situations to power a sensor or charge the battery from a connected object. The limit of the experience is the relative proximity of the object connected to the wireless transmitter of the order of a few meters. Rest researchers to demonstrate the approach in the countryside with the TV airwaves.
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Source : “First Demonstration of a Surveillance Camera Powered by Ordinary Wi-Fi Broadcasts”, MIT Technology Review, June 3, 2015