The diode was then put to good use to rectify random high-frequency WiFi signals into DC electricity. The MoS2 rectenna is ultra-thin and flexible, and could be fabricated in a roll-to-roll process to cover very large areas, making up for its relatively low efficiency compared to proven silicon-based rectennas, the researchers anticipate.
The rectenna described in Nature consists of a flexible RF antenna that captures electromagnetic waves and passes on the AC signal to the MoS2 Schottky diode which converts it into a DC voltage. Such a rectenna could passively captures and transforms ubiquitous Wi-Fi signals into useful DC power for battery-free devices, or it could be made into large areas to harvest more power for multiple sensors monitoring large infrastructures.
In their experiments, the researchers were able to produce about 40 microwatts of power when exposing their device to the typical power levels of Wi-Fi signals (around 150 microwatts), enough power to light up an LED or drive silicon chips. The rectenna could also harvest WiFi signals to power implantable medical devices without the risks associated with potential battery leakage.