Big renewable energy source could be at our feet – literally: U of Wisconsin

energy-at-our-feet-161020131916_1_540x360Associate Professor Xudong Wang holds a prototype of the researchers’ energy harvesting technology, which uses wood pulp and harnesses nanofibers. The technology could be incorporated into flooring and convert footsteps on the flooring into usable electricity.
Credit: Stephanie Precourt/UW-Madison
Source: University of Wisconsin-Madison




Flooring can be made from any number of sustainable materials, making it, generally, an eco-friendly feature in homes and businesses alike. Now, flooring could be even more “green,” thanks to an inexpensive, simple method that allows them to convert footsteps into usable electricity.

Flooring can be made from any number of sustainable materials, making it, generally, an eco-friendly feature in homes and businesses alike.

Now, flooring could be even more “green,” thanks to an inexpensive, simple method developed by University of Wisconsin-Madison materials engineers that allows them to convert footsteps into usable electricity.

Xudong Wang, an associate professor of materials science and engineering at UW-Madison, his graduate student Chunhua Yao, and their collaborators published details of the advance Sept. 24 in the journal Nano Energy.

The method puts to good use a common waste material: wood pulp. The pulp, which is already a common component of flooring, is partly made of cellulose nanofibers. They’re tiny fibers that, when chemically treated, produce an electrical charge when they come into contact with untreated nanofibers.

nano-fiber-flooring-button-3When the nanofibers are embedded within flooring, they’re able to produce electricity that can be harnessed to power lights or charge batteries. And because wood pulp is a cheap, abundant and renewable waste product of several industries, flooring that incorporates the new technology could be as affordable as conventional materials.


While there are existing similar materials for harnessing footstep energy, they’re costly, nonrecyclable, and impractical at a large scale.

Wang’s research centers around using vibration to generate electricity. For years, he has been testing different materials in an effort to maximize the merits of a technology called a triboelectric nanogenerator (TENG). Triboelectricity is the same phenomenon that produces static electricity on clothing. Chemically treated cellulose nanofibers are a simple, low-cost and effective alternative for harnessing this broadly existing mechanical energy source, Wang says.

The UW-Madison team’s advance is the latest in a green energy research field called “roadside energy harvesting” that could, in some settings, rival solar power — and it doesn’t depend on fair weather. Researchers like Wang who study roadside energy harvesting methods see the ground as holding great renewable energy potential well beyond its limited fossil fuel reserves.

“Roadside energy harvesting requires thinking about the places where there is abundant energy we could be harvesting,” Wang says. “We’ve been working a lot on harvesting energy from human activities. One way is to build something to put on people, and another way is to build something that has constant access to people. The ground is the most-used place.”

Heavy traffic floors in hallways and places like stadiums and malls that incorporate the technology could produce significant amounts of energy, Wang says. Each functional portion inside such flooring has two differently charged materials — including the cellulose nanofibers, and would be a millimeter or less thick. The floor could include several layers of the functional unit for higher energy output.grand-central-station-footsteps

“So once we put these two materials together, electrons move from one to another based on their different electron affinity,” Wang says.

The electron transfer creates a charge imbalance that naturally wants to right itself but as the electrons return, they pass through an external circuit. The energy that process creates is the end result of TENGs.

Wang says the TENG technology could be easily incorporated into all kinds of flooring once it’s ready for the market. Wang is now optimizing the technology, and he hopes to build an educational prototype in a high-profile spot on the UW-Madison campus where he can demonstrate the concept. He already knows it would be cheap and durable.

“Our initial test in our lab shows that it works for millions of cycles without any problem,” Wang says. “We haven’t converted those numbers into year of life for a floor yet, but I think with appropriate design it can definitely outlast the floor itself.”

Story Source:

Materials provided by University of Wisconsin-Madison. Original written by Will Cushman. Note: Content may be edited for style and length.

Journal Reference:

  1. Chunhua Yao, Alberto Hernandez, Yanhao Yu, Zhiyong Cai, Xudong Wang. Triboelectric nanogenerators and power-boards from cellulose nanofibrils and recycled materials.Nano Energy, 2016; 30: 103 DOI:10.1016/j.nanoen.2016.09.036

Vets Using Nanotechnology To Help Pets’ Healing: “Nano-Fibers”

mastiff-02Modern medicine is evolving quickly.

Now, with the introduction of bioengineering, doctors can have tissue made for their patients and veterinarians are having great success using nanotechnology in our pets.

“The part that I focus on is tissue engineering, where we are basically focusing and building or engineering new tissue for the body,” Dr. Johnson said.

Their nanotechnology is an integral part of regenerative medicine.

“We’ve all seen regeneration. We’ve all had cuts on our hands, right? And those cuts heal. So, our body is capable of healing, but we have to provide the right environment,” Dr. Johnson said.

Enter nanofibers. (Follow the Link Below to Watch the Video Clip)


It takes a hundred of the microscopic fibers laid side-by-side to be as wide as a human hair. Weave them together, and they provide a framework for healing.


“Great Things from Small Things”

“Cells and tissue can’t move across open space, they have to crawl on something, and this is really the key aspect to having a scaffold is it allows those cells to have a highway to move on to refill that wound, regenerate that native tissue,” Dr. Johnson said.

“You can’t do that synthetically. I mean, we can’t do that without the help of what someone like Dr. Johnson’s doing with nanofibers,” Dr. Mike Hutchinson said.

Dr. Hutchinson, of Animal General in Cranberry, uses nanofibers in combination with stem cells to speed up the healing.

“They will do a lot of good for as long as they stay, but we would like to keep them there longer in that damaged environment. So, they have made some nanowhiskers, if you will, that we mix with the stem cells before we inject them in, and they will hold them there. They will give them something to grow on or to hug to and keep them there longer,” Dr. Hutchinson said.

Panzer was the first dog in the United States to receive the nanofiber treatment. In April, he was recovering from a knee injury when he suffered a setback.

“He was healing well. We were doing cage rest, leash walking. Everything was going great and then, I took him for a little walk down to the mailbox, and he slipped on a piece of ice and pulled his ligament completely,” Sharon Germain said.

Dr. Hutchinson told Sharon about nanotechnology and stem cells to help repair the torn ACL.

“When Dr. Mike first introduced it to me, I just sat there wide-eyed going, ‘Really?’ And I said, ‘Anything to just help things heal better and make him feel better.’ I was on board immediately,” Germain said.

They did the surgery right away.

“I have used it in 15 dog joints where we are injecting it right into the dog joints with the stem cells. And we have used it on skin and we have also used it in some muscle — actually in a police dog to try to repair a damaged muscle on a service dog,” Dr. Hutchinson said.

Seven months later?

“It’s amazing, and seeing is believing,” Germain said. “It does your heart good when you see this.”

In a matter of months, Panzer regained complete range of motion in the knee and is back to being a healthy, rambunctious dog.

For Sharon, it’s still staggering that it is medically possible.

“It’s almost like being in the Jetson years of life. You are seeing tomorrow’s technology today,” Germain said.

“Tissue engineering is here. Regenerative medicine is here, and we are finally moving from the hype of stem cells to the results of stem cells. You’re going to see a lot of the benefit coming in the next years,” Dr. Johnson said.

And for Dr. Hutchinson?

“Talking to people who told me this was fairy dust or this is voodoo, they said haven’t seen it. They just haven’t seen it. They haven’t read about it. They aren’t picking up the literature that is being published in Germany or Japan or China or Australia or in Israel and they are saying it’s not in a journal here so it doesn’t exist,” Dr. Hutchinson said.

Here’s another big advantage to using nanofibers.

They are engineered to dissolve after a specified amount of time, and are processed like lactic acid, which leaves nothing but the patient’s own tissue behind.

Dr. Jed Johnson has a PhD in engineering and his firm engineers body tissue.