The wireless devices will soon go battery free and create a network for information exchange out of thin air. Say hello to a new technique called Ambient Backscatter created by professors at the Washington University. The technique relies on the TV and cellular transmissions that are already surrounding us at any moment of time. The researchers have developed small battery-free prototype devices that can identify the TV / Cellular signal using antennas and harness them. This technology, the researchers say, will enable forming a network of devices and sensors that can communicate with each other without needing an external power source or human attention.


Shyam Gollakota, assistant professor of CS & Engineering says that the researchers were able to repurpose the wireless signals that already exist in the air into both source of power and a communication medium. He expects that the technology will have applications in a number of areas like wearable computing, self-powered sensor networks and smart homes etc.

Sensors built using Backscatter Technique can be built inside nearly any structure and can communicate with each other. That is, an array of sensors built inside a bridget will be able to monitor the health of the concrete as well as the steel columns / strings. The rate at which the sensors could communicate with each other was about 1 kbps when separated 2.5 ft outdoors and about 1.5 ft. indoors. This data transmission rate is just enough to send the sensor readings, text messages and contact information as well.

The technical details of the technology are available in the source link (pdf).

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