Imagine small devices that power themselves by exploiting the energy dispersed by the Wi-Fi and Bluetooth signals that surround us every day. It’s not science fiction, but a reality made possible thanks to a new invention called rectennaa rectifying antenna that converts electromagnetic waves into electricity.
By exploiting a technology based on quantum phenomena, this innovative rectenna manages to capture even the weakest signals and transform them into enough energy to power small devices, such as temperature sensors or electronic devices.Internet of Things (IoT).
How the rectenna works
The rectenna is a component that receives electromagnetic signals, such as those from Wi-Fi, Bluetooth and mobile networks, and converts them into electric current. The antenna captures these waves as alternating current (AC), which is then transformed into direct current (DC) through a rectifier circuit.
Although the idea of ​​generating energy from radio signals dates back to the 1960s, the real progress of this new rectenna lies in its ability to exploit very weak environmental signals. If in the past energy was sent directly to devices via microwaves, now the goal is to capture electromagnetic waves diffused in the environment, such as those from Wi-Fi routers or smartphones.
To achieve this, the researchers used a data-based approach spintronicsa field that studies the behavior of electron spin and its interactions with magnetic fields. They designed a series of spin rectifiers (SR), nanoscale devices composed of magnetic tunnel junctions (MTJs). These components have been optimized to pick up common frequencies such as Wi-Fi (2.4 GHz) and 5G (3.5 GHz).
Practical applications and environmental benefits
Tests showed that an array of spin rectifiers was able to generate enough energy to power a commercial temperature sensor. This result was achieved with a power level of just -27 dBm, an extremely low value when compared to the power of a normal smartphone, which transmits at around 27 dBm.
This technology could have a significant impact on theInternet of Things (IoT)where the need to power large numbers of sensors and devices is continually growing. Powering these devices with environmental signals would reduce dependence on batteries, lowering maintenance costs and improving the sustainability of wireless networks.
The developers of this rectenna point out that large-scale adoption could help decrease the carbon footprint associated with IoT technologies, offering a greener and more accessible energy solution.
