One of the things holding back a more widespread push towards the Internet of Things — making everyday objects smarter and network connected — is battery technology. Computing power, and lately storage capacity, have increased and are still increasing exponentially. However battery technology has lagged behind.
If you pry open your laptop you’ll find a lot more of it is dedicated to the battery than it was a few years back. While the electronics inside your laptop have decreased in size, and so also has the amount of power it’s using for basic computer, overall your laptop is doing so much more for you these days (wifi/4g connectivity, higher-resolution screens running bigger video, longer-expected daytime use) and the power needs have increased, not decreased.
While technologies like Bluetooth Low Energy have arrived to decrease the amount of power needed — designed for use in embedded devices Bluetooth LE lives up to its name, allowing embedded devices to last for weeks or months on a single coin cell — one of the main drains on that battery is wireless.
Which isn’t necessarily a problem for laptops, but when it comes to the Internet of Things and the almost-inevitable evolution towards Smart Dust, then it is a problem. If computing is ever truly going to become ambient, then how to power it is a major stumbling block.
While tiny solar cells and other passive power generation techniques, like vibration harvesting, have already been scaled down fairly successfully, anything that can reduce the power requirement is going to be looked at with a lot of interest.
A team at the University of Washington has just come up with something that is certainly going to generate that sort of interest. They’re using existing TV and cellular transmissions — ambient RF energy that’s in the air around already — both as a communication medium, and as a source of power.
Unlike NFC, where power is supplied by the reader device, here neither the reader nor the transmitter are powered. Both devices are battery free, and while the data rates are fairly low, they’re communicating at much higher ranges than NFC is capable of, with reliable transmission of several feet. That’s pretty impressive.
If developed properly, this technology could enable a lot of new use cases for the Internet of Things, including the permanent installation of embedded devices in hard-to-service areas: inside walls and other structures, and also in everyday objects.
If the person loses their keys, the couch can can use ambient backscatter to communicate with the lost keys, and then alert the user. This technology could enable smart homes, smart cities—and an Internet of Things.
This new technology arriving could also mean that the growing ubiquity of NFC could be short-lived.
Original paper: Ambient Backscatter: Wireless Communication Out of Thin Air, Liu, Parks, Talla, Gollakota, Wetherall & Smith, 2013, Proceedings of the ACM SIGCOMM Conference