The system, for now, can transmit data at a speed of 16 kilobits per second
(sustainabilityenvironment.com) – What if sunlight replaced current Wi-Fi technology? What if a “simple” window was enough to replace home routers? This possibility is being worked on by a group of scientists from King Abdullah University of Science and Technology (KAUST), Saudi Arabia. The researchers have created a “smart glass” that can polarize sunlight and offer a low-energy alternative to traditional Wi-Fi.
A luminous path for wireless communications
A luminous path for wireless communications
The manipulation of LED lights as a communication tool has garnered considerable attention in recent years. The vast majority of work in this field focuses on the modulation of light intensity but a second pathway that employs the direction of polarization as a vector of information is also slowly making its way. Changes in intensity or polarity can have the same function as 1 and 0 in the binary code; and just the camera of a smartphone to detect and decode them. But if the former can also be perceived by the human eye (and not be too pleasant), the latter are practically invisible.
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It is exactly at this level that Saudi research fits in but with a big and fundamental difference: the light used is not artificial but natural. Professor Basem Shihada, head of the group, explains how the idea came about. “I was just hoping to use a cell phone camera to record an encoded stream of light, try to decode the video and retrieve the data; that’s when I thought, ‘Why not do the same with sunlight? It would be much easier’. So we started exploring sunlight as a carrier of information“.
Liquid crystals and sunlight for KAUST smart glass
To take advantage of the sun, the team designed a two-part communication system. “There is a light modulator that can be incorporated into a glass surface and a receiver in the room,” explains researcher Osama Amin. “The modulator is an array of our smart glass elements known as Dual-cell Liquid Crystal Shutters (DLS)”. The matrix of the liquid crystal shutter acts as a filter to encode the signals in the light that passes through the glass. To operate it requires only 1 watt of power, where traditional Wi-Fi routers use between 5 and 20 watts. Calculations indicate that in its current form the smart Glass could transmit data at a speed of 16 kilobits per second, but scientists obviously want to increase capacity. “We are now ordering the necessary hardware for the implementation of a test bench prototype,” said Professor Shihada. “We would like to increase the speed of data from kilobits to mega and gigabits per second“.
