Researchers in Stanford University’s Department of Electrical and Computer Engineering have introduced HitchHike, an ultra-low-energy wireless radio.

The Internet of Things (IoT) is expected to rely on miniature, energy-efficient WiFi radios to pass commands between the network to connected devices. HitchHike could be one link in this communications chain.

According to researcher Pengyu Zhang, “HitchHike is the first self-sufficient WiFi system that enables data transmission using just micro-watts of energy—almost zero.” A single battery could power it for a decade or more. The device has a range of about 50 meters and can transmit up to 300 kilobits per second. It is compatible with existing devices, such as cell phones and WiFi routers.

The HitchHike prototype is both a processor and radio. It is about the size of a postage stamp, but the engineers say that they can make it smaller—perhaps even smaller than a grain of rice for use in implanted bio-devices like a wireless heart rate sensor. Its technology is based on backscatter radio, where incoming radio waves are bounced back into the atmosphere. Rather than reflect identical radio waves back, a HitchHike passes along only the “words” – strings of ones and zeros – that conform to the message the device wants to send.

The research team says HitchHike could be available for incorporation into wireless devices in the next three to five years.