Imagine a world where smartphones, laptops, wearables, and other electronics are powered without batteries. Researchers from MIT and Technical University of Madrid invented a device that harvests energy from Wi-Fi signals and converts them into electricity that can power devices, wire- and battery-free.
The device, known as ‘rectenna’ – combination of rectifying antenna is a type of antenna that converts electromagnetic energy into direct current (DC). The device uses a radio-frequency antenna to capture electromagnetic waves, like those produced by Wi-Fi, as alternating current (AC) waveforms.
These waveforms are then sent to 2D semiconductor that converts them into DC, producing about 40 microwatts from about 150 microwatts of Wi-Fi power. This much energy is enough to power small wearables, or medical electronic devices, eliminating the need for batteries.
Due to the device being flexible, the rectenna can be deployed over large areas akin to wallpaper, or used in small, portable devices like flexible smartphones. The device could even be used in medical implants and swallow-able sensors.
“Ideally you don’t want to use batteries to power these systems, because if they leak lithium, the patient could die. It is much better to harvest energy from the environment to power up these small labs inside the body and communicate data to external computers,” said engineer Jesus Grajal.
Moreover, the rectenna also relatively costs lower at larger scales and hence can be used for much bigger applications. “We have come up with a new way to power the electronics systems of the future by harvesting Wi-Fi energy in a way that’s easily integrated in large areas to bring intelligence to every object around us,” said engineer Tomás Palacios.