The biggest drawback of modern communication devices like your smartphone is the need for constant power. Battery life is the limiting factor of modern technology, but what if it wasn’t? Scientists at the University of Washington have developed prototype “ambient backscatter” devices which use the RF signals that are generated by TV and cellphone broadcast towers to communicate with each other without the need for batteries to power them. Because they don’t have batteries they don’t generate their own signal instead they communicate by absorbing or reflecting binary information from existing signals.

The other benefit to the lack of a battery is that these devices are always on, they can be buried inside structures and left to give data forever without any thought to maintenance. The devices were even able to work up to up to 10km away from the nearest tower broadcasting a strong wireless signal. The devices are a potentially major breakthrough in the growing drive to create the Internet of Things; a network of devices that provide data that can be mined to better understand everyday things around us like how well a sewage system copes during half time at a football match at FNB stadium with 90 000 people all hankering for some relief.