The next generation of wireless technology may harness the human body for energy

The next generation of wireless technology will harness the human body for energy

Researchers at the University of Massachusetts Amherst use the human body to collect waste energy to power wearable devices

While you may just be beginning to enjoy the benefits of 5G wireless technology, researchers around the world are already working the future: 6G
.
One of the most promising breakthroughs in 6G communication is the possibility of visible light communication (VLC), which is like the wireless version of fiber optics that uses flash light to transmit information
.
Now, a team of researchers at the University of Massachusetts Amherst have announced that they have invented a low-cost, innovative way to use the human body as an antenna to harvest waste energy from VLCs
.
This waste energy can be recycled to power a range of wearable devices and perhaps even larger electronics
.

"VLC is very simple and interesting, it does not use radio signals to send information wirelessly, but uses light emitted by LEDs that can be turned on and off 1 million times
per second.
Part of VLC's appeal is that infrastructure is already ubiquitous – our homes, cars, streetlights, and offices are all illuminated by LED bulbs and are transmitting data
.
Anything with a camera, such as a smartphone, tablet, or laptop, can be a receiver
.
”

Previously, Jie Xiong and first author Minhao Cui, a graduate student in information and computer science at the University of Massachusetts Amherst, showed that there is a significant energy "leakage" in VLC systems because LEDs also emit "side-channel RF signals," or radio waves
.
If this leaked RF energy can be harvested, it can be put into use
.

The team's first task was to design an antenna wrapped with copper wires to collect leaky RF, and they did
.
But how to maximize energy harvesting?

The team experimented with a wide variety of design details, from the thickness of the wires to the number of times the coils were wound, but they also noticed that the efficiency of the antenna varied
depending on what the antenna touched.
They tried putting coils on plastic, cardboard, wood and steel, and they tried hitting walls of varying thicknesses, on phones and laptops turned on and off
.
Then Cui had an idea to see what happens
when the coil comes into contact with the human body.

Soon, it became clear that the human body was the best medium for amplifying coils to collect leaking RF energy, ten times
more than bare coils.

After many experiments, the team came up with "Bracelet +", a simple copper wire coil that is worn on the upper part of the forearm as a bracelet
.
While this design can be worn as a ring, belt, anklet, or necklace, this bracelet seems to strike the right balance
between energy harvesting and wearability.

"This design is cheap—less than 50 cents," notes that their paper won the best paper award
at the prestigious Association for Embedded Network Sensor Systems Conference.
"But Bracelet+ can reach microwatts, enough to support many sensors, such as physical health monitoring sensors, due to the low sampling frequency, long sleep mode duration, low operating power consumption
.
"

"Ultimately, we hope to be able to harvest waste energy from a variety of sources to power
the technologies of the future.
"