Over 64 billion IoT devices, which run on batteries, are expected to be deployed by 2025. The batteries’ chemical components could be extremely harmful to the environment, so it’s important to remove them without sacrificing communication performance and IoT services. Researchers at IMDEA Networks Institute in Madrid have unveiled a crucial sustainable wireless communication system, called PassiveLiFi, which could lead to battery-free devices. Of course, this would be achieved through LiFi and radio frequency (RF) backscatter. It could be used in smart homes, smart cities, and smart agriculture applications.
The IMDEA team’s PassiveLiFi concept involves running IoT devices on energy produced from LEDs and data provided by modulating these LEDs, a method called LiFi. IoT devices would transmit data by reflecting and modulating the incoming RF signals present in the environment, a passive transmission technique known as RF backscattering that consumes very little power.
“Our work opens the door to long-range, battery-free Internet of Things applications retrofitting lighting infrastructure for communication, something that was not previously possible to achieve. It’s the result of three years of research; when we started, LiFi technology and RF backscattering were considered independent technologies, and we have shown that LiFi can solve the limitations of RF backscatter and that LiFi can be applied to a new field, battery-free communication” says Dr. Giustiniano, Research Associate Professor at IMDEA Networks Institute.
“Solar cells have been widely used to harvest energy. In this work, we go a step further and demonstrate that they can be used efficiently and simultaneously as both a source of power harvesting and as a communications receiver," noted Borja Genovés Guzmán, Post-Doc Researcher at IMDEA Networks and one of the co-authors of the scientific paper. "Our solution solves the trade-off between the captured energy required by the IoT device and the desired data rate, allowing our system to operate without using batteries."
More details can be found in the team's paper.