Once of the biggest challenges in developing wearable devices is energy storage. Wearables, like any other mobile device, need to be as small and light as possible. That means that bulky, heavy batteries are a major constraint in their design. This new antenna design created by researchers at MIT, as well as many other institutions, solves that problem by harvesting the energy from the radio waves all around us.
That, by itself, isn’t a new concept; energy-collecting antennas, called rectennas, have been around for a long time. But, traditional rectenna designs have a lot of drawbacks: they’re relatively expensive by area, they’re rigid, and they can only harvest energy from a limited portion of the radio wave spectrum. This new design utilizes an inexpensive material called molybdenum disulfide (MoS2) that results in thin, flexible rectennas that can collect energy from a wide range of radio waves.
With the MoS2 material, they are able to build the rectifier portion of the antenna at just three atoms thick. That means these antennas can be incorporated into thin, lightweight, and even flexible wearable devices. Such an antenna can harvest electricity with up to 40% efficiency from wireless signals up to 10 gigahertz, which includes Wi-Fi and cellular signals that are always around us — but which usually just go to waste.
Because they’re inexpensive to construct, these new rectennas have potential in a wide range of industries. They could be used to power implantable medical devices where the safety of batteries is a concern. Thinking on a much larger scale, the researchers believe these could also be used to power entire smart roads, bridges, and other civil engineering structures.
MIT Creates Antennas for Wearables That Harvest Energy From Wi-Fi Signals was originally published in Hackster Blog on Medium, where people are continuing the conversation by highlighting and responding to this story.