Spurred by the movement to reach carbon neutrality, technology continues to seek ways to reduce its energy consumption. A new form of renewable energy may be on the horizon via a wearable microgrid: Human Power.
When businesses look to reduce their impact on the environment, their first step is often to undergo digital transformation. This is definitely a step in the right direction, but some businesses do not understand that digital processes still consume large amounts of energy. We have made great strides in reducing our carbon footprint worldwide, but technology will soon outpace the mitigation we currently have in place. Rest assured, when it comes to technology, no one stops innovating. A new method of reducing energy consumption by technology has come to light: A “wearable microgrid” that harvests energy from the human body to power electronic gadgets.
A group of nanoengineers at the University of California San Diego took their inspiration from community microgrids when they came up with this idea. The microgrid consists of three parts: sweat-powered biofuel cells, triboelectric generators (powered by motion) and energy-storing supercapacitors. Each part is flexible, can be washed and can be screen-printed onto clothing.
“We’re applying the concept of the microgrid to create wearable systems that are powered sustainably, reliably and independently,” said co-first author Lu Yin, a nanoengineering Ph.D. student at the UC San Diego Jacobs School of Engineering. “Just like a city microgrid integrates a variety of local, renewable power sources like wind and solar, a wearable microgrid integrates devices that locally harvest energy from different parts of the body, like sweat and movement, while containing energy storage.”
In order to get the most out of the system, the microgrid is screen-printed onto clothing strategically. Biofuel cells that harvest energy from sweat are placed on the chest, triboelectric generators are placed on the forearms and sides of the torso or on the legs, and supercapacitors are outside the shirt on the chest, where they temporarily store energy from the other two devices before discharging it.
The two devices compliment each other to increase the impact. It begins immediately when a user starts moving, the triboelectric generators provide power instantaneously. As the user continues to move and starts to sweat, the biofuel cells kick in and add to the power provided. It’s continuous while the user is moving, and the power lasts after the user stops moving as well.
During testing, subjects participated in 30-minute sessions. The sessions entailed 10 minutes of exercise (either cycling or running) and then 20 minutes of rest. In that time, the wearable microgrid powered either an LCD wristwatch or a small electrochromic display throughout each session.
We won’t get into the nitty gritty of how this technology works, it’s a pretty complex combination of science and technology, but we will ponder applications and potential implications of this technology. First, flexible silver interconnections that are insulated by waterproof coating connect the parts of the microgrid and are also printed on the shirt. These connections, along with the devices attached, are not impacted by repeated bending, folding or crumpling. It can be washed, but in water only, no detergent can be used. Still, the fact that all of this can be screen-printed on to a shirt is pretty innovative.
On top of being embedded into clothing, researchers are continuing to work on this project to explore additional applications. This system is designed for athletics or other cases where the user is exercising, but they aren’t stopping there or limiting themselves to anything. Imagine being able to charge your phone or ear buds while on a run, without a portable charger. And what about when someone creates a way to store more of that energy for longer, or get that energy to last longer through more efficient conversion?
Harnessing the power of the human body, power which we generate simply by moving our limbs, is not only forward-thinking, it breeds efficiency. Currently, the energy we create when we move does nothing but move our bodies. Any extra power we create goes unused, so why not take that and use it to our advantage? Solar power, wind power and, to some extent, hydraulic power are all forms of renewable energy. Frankly, modern wind power works much like the microgrid here. If we can truly make use of this wearable microgrid, we can add “Human Power” to the list of renewable energy sources.