A miniature, self-sufficient WiFi device which uses virtually no energy has the potential to be the “missing link” for the internet of things, its developers at Stanford University in the US claim.
Hitchhike is designed to fill the need for energy-efficient WiFi radios to pass commands to and from the internet to potentially billions of devices, including those tiny enough to fit inside implanted bio-devices such as wireless heart rate sensors.
The prototype is a processor and radio in one, using a technology based closely on what is known as backscatter radio, and named HitchHike for its ability to hitch hike on incoming radio waves from a smartphone or a laptop. It translates those incoming signals to its own message and retransmits its own data on a different WiFi channel.
With a range of up to 50 meters, able to transmit up to 300 kilobits per second and use electromagnetic energy, plucked from its surroundings, to power itself perhaps indefinitely, the Stanford team says it could “lead to widespread adoption in the internet of things”.
A video explains the technology:
“HitchHike is the first self-sufficient WiFi system that enables data transmission using just microwatts of energy, almost zero,” says postdoctoral researcher Pengyu Zhang.
“Better yet, it can be used as is with existing WiFi without modification or additional equipment. You can use it right now with a cell phone and your off-the-shelf WiFi router.”
“Sensors could be deployed anywhere we can put a coin battery that has existing WiFi,” adds team leader Sachin Katti.
“The technology could potentially even operate without batteries. That would be a big development in this field.”
The team demonstrated the potential of HitchHike in a paper presented at the Association for Computing Machinery’s SenSys Conference earlier this month. They believe it could be available to be incorporated into wireless devices in the next three to five years.