Tag Archives: wearable batteries

Bake and shake your t-shirt to make a flexible electronic device

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I don’t think you actually need to shake but you do need to bake your cotton t-shirt, albeit in a special way, to create a wearable battery  or so the University of South Carolina’s Xiaodong Li says. Excerpted from the June 29, 2012 news item on Nanowerk,

Over the years, the telephone has gone mobile, from the house to the car to the pocket. The University of South Carolina’s Xiaodong Li envisions even further integration of the cell phone – and just about every electronic gadget, for that matter – into our lives.

…

“We wear fabric every day,” said Li, a professor of mechanical engineering at USC. “One day our cotton T-shirts could have more functions; for example, a flexible energy storage device that could charge your cell phone or your iPad.”

Li is helping make the vision a reality. He and post-doctoral associate Lihong Bao have just reported in the journal Advanced Materials (“Towards Textile Storage from Cotton T-Shirts”) how to turn the material in a cotton T-shirt into a source of electrical power.

I’ve been following the ‘wearable battery’ story for a while (the May 9, 2012 posting is the most recent) but Li’s approach is a little different.  Excerpted from the June 29, 2012 University of South Caroline news release by Steven Powell,

Starting with a T-shirt from a local discount store, Li’s team soaked it in a solution of fluoride, dried it and baked it at high temperature. They excluded oxygen in the oven to prevent the material from charring or simply combusting.

The surfaces of the resulting fibers in the fabric were shown by infrared spectroscopy to have been converted from cellulose to activated carbon. Yet the material retained flexibility; it could be folded without breaking.

“We will soon see roll-up cell phones and laptop computers on the market,” Li said. “But a flexible energy storage device is needed to make this possible.”

The once-cotton T-shirt proved to be a repository for electricity. By using small swatches of the fabric as an electrode, the researchers showed that the flexible material, which Li’s team terms activated carbon textile, acts as a capacitor. Capacitors are components of nearly every electronic device on the market, and they have the ability to store electrical charge.

Here’s what makes the approach different; it’s ‘green’ according to Powell’s news release,

Li is particularly pleased to have improved on the means by which activated carbon fibers are usually obtained. “Previous methods used oil or environmentally unfriendly chemicals as starting materials,” he said. “Those processes are complicated and produce harmful side products. Our method is a very inexpensive, green process.”

Somehow I’ve always seen ‘wearable batteries and/or electronics’ as opportunities for electrocution but I seem to be alone with this fear as there’s never any discussion about the safety issues might arise.

ETA July 3, 2012: Dexter Johnson in his June 29, 2012 posting on Nanoclast (a blog on the IEEE [Institute of Electrical and Electronics Engineers] website) notes that the simplicity of Li’s process may be specially exciting,

While Li makes mention of the environmentally friendly chemicals used to impart this capability to a t-shirt, it is perhaps the simplicity of the process that will likely be the most intriguing aspect to manufacturers.

Participatory science; wearable batteries; radio interview with Andrew Maynard; shadow science ministers in Canada’s political parties

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Ordinary people (nonscientists like me) have a long tradition of participating in scientific research in areas such as astronomy and ornithology (bird watching). A local example is the eagle count which takes place at Brackendale every year. (Aside: The 2010 count has already taken place but it’s still possible to attend festival events which are now part of the Brackendale eagle count experience.)

Someone whose science interests may be more esoteric can have trouble finding opportunities to pursue their interests. Thanks to the Science Cheerleader there is a new online resource to help you find a project. From the Science Cheerleader blog,

Hot diggity-DOG! After years in the making, my partner, Michael Gold, and I–with generous support from Science House–have officially unveiled the beta version (that means this is still a work-in-progress) of ScienceForCitizens.net . Science journalist, Carl Zimmer, who frequently writes for Discover and Time Magazine, said “It’s like Amazon.com for all sorts of possibilities for doing cool citizen science”. We’ll take that

And thanks to the Pasco Phronesis blog for the info. about the Science Cheerleader.

For an abrupt change of pace: Yes, you could be wearing your batteries at some point in the future. Scientists at Stanford University (CA) have found a way to easily and inexpensively turn cotton or polyester fibres into batteries or, as they call it, wearable energy textiles or e-textiles. From the news item on BBC News,

“Wearable electronics represent a developing new class of materials… which allow for many applications and designs previously impossible with traditional electronics technologies,” the authors [of the study published in ACS Nano Letters] wrote.

A number of research efforts in recent years have shown the possibility of electronics that can be built on flexible and even transparent surfaces – leading to the often-touted “roll-up display”.

However, the integration of electronics into textiles has presented different challenges, in particular developing approaches that work with ordinary fabrics.

Now, Yi Cui and his team at Stanford University in the US has shown that their “ink” made of carbon nanotubes – cylinders of carbon just billionths of a metre across – can serve as a dye that can simply and cheaply turn a t-shirt into an “e-shirt”.

I’ve taken a look at the research paper which, as these things go, is pretty readable. Bravo to the American Chemical Society (ACS) for not placing the material behind a paywall. The article, Stretchable, Porous and Conductive Energy Textiles,  published in the ACS journal Nano Letters is here.

I had the pleasure of listening to a radio interview on Whyy Radio conducted by Marty Moss-Coane where she interviewed Dr. Andrew Maynard, Chief Science Advisor for the Project on Emerging Nanotechnolgies. The interview (approximately 50 mins.)  titled, The Science and Safety of Nanotechnology, is available for listening here. Moss-Coane was well-prepared, asked good questions, and had listeners call in with their own questions. Dr. Andrew Maynard was, as always, very likable and interesting.

After my recent posting on science policy in Canada and the four major political parties, I thought I’d check out the various shadow science ministers or critics. Here’s what I found,

Gary Goodyear, Conservative, Minister of State (Science and Technology)

Jim Maloway, NDP, Science and Technology [portfolio]

Frances Coates, Green Party, shadow minister Science and Technology

Marc Garneau, Liberal Party, Industry, Science and Technology critic

I have looked at all their websites and Garneau seems the most interested in science and technology issues. Given that he’s a former astronaut and is an engineer, one might expect that he would have a major interest in the subject. He’s written a paper on the subject (thanks to the folks at The Black Hole for finding it). If you go here and either read or scroll to the bottom, you will find a link to his paper. He also has a poll on his website, What is the importance of science and technology to create the jobs for tomorrow? You can go here to answer the question. As for the others, Goodyear lists a series of announcements in news releases as accomplishments which makes identifying his actual accomplishments difficult. Jim Maloway does not mention science on his website and Frances Coates posted a few times on her blog in 2008 but made no mention of science.