2013-04-25

Why Digital Clothing Won't Need Batteries

For wearables to really take off, we’ll need powerful and sophisticated devices that are lightweight, elegant, and small enough to be worn as accessories—or embedded into the fabric of our clothes. But what about the batteries?



Wearable devices are likely to be always on, running in the background to wirelessly send and receive updates, as well as perform more power-sucking tasks like running apps or streaming video. To keep the wearer from having to juice up at an outlet every few hours, manufacturers are going to need to find some smart solutions for powering these devices.

A burgeoning industry in energy-harvesting fabrics and sensors seeks to capture the ambient energy all around us to make wearables work smarter, not harder. One expert is Professor Joanna Berzowska, chair of the Department of Design and Computation Arts at Concordia University in Canada, who has been developing interactive electronic fabrics that do exactly that by capturing and storing energy from the human body.

“Our goal is to create garments that can transform in complex and surprising ways--far beyond reversible jackets, or shirts that change color in response to heat. That’s why the project is called Karma Chameleon,” says Berzowska. The major innovation of this research project is the ability to embed these electronic or computer functions within the fiber itself: rather than being attached to the textile, the electronic components are woven into these new composite fibers. The fibers consist of multiple layers of polymers, which, when stretched and drawn out to a small diameter, begin to interact with each other. The fabric, produced in collaboration with the École Polytechnique’s Maksim Skorobogatiy, represent a significant advance in the development of “smart textiles.”

Unfortunately, it’ll be another 20 to 30 years before we’ll actually be able to manufacture clothing with these composite fibers. However, Berzowska’s prototypes allow designers to start envisioning how such clothing might look and behave, paving the way for T-shirts that double as mobile phone chargers or shape-shifting garments that react to a particular environmental setting or situation.

Several other research-stage energy-harvesting devices were recently displayed at the Printed Electronics Europe 2013 conference in Berlin. The trade show portion of the conference featured everything from vibration-powered sensors to photovoltaic fabrics.

Perpetuum‘s Vibration Energy Harvester (VEH) is a wireless sensor that gets attached to rotating components, such as wheel bearings, on trains. Cleverly, the device both measures and is powered by mechanical vibration. It also measures temperature, and it wirelessly transmits the results to the train’s operator so they can immediately spot a failure in its early stages.

Another EU-funded project called Powerweave aims to create two kinds of fiber--one for harvesting solar energy and the other for storing it--that can be woven together into one self-contained system. This could theoretically be used to power soft sensors in clothing, but there are far more large-scale applications in store.

According to Christian Dalsgaard, founder of consortium member Ohmatex, the goal is to create a fabric that can generate 10W per square meter. Once that is achieved, he noted, there are “no limits to how big such a fabric can be made,” and a 100-square-meter piece of fabric would in theory be able to generate a kilowatt of power.

Sounds promising. But once again, the research has a long way to go before this tech will be ready to hit the market in the form of a pair of jeans. Sure, watch manufacturers have been making use of kinetic and photovoltaic energy harvesting for years to power self-winding wrist watches, but the process gets considerably more complicated when you’ve got a Mac Mini in there. Looks like we won’t be seeing these same techniques put to use in our mobile phones or Nike FuelBands just yet, but this tech will be part of what makes or breaks the wearable computing trend in years to come.


Backtrack by reading our series about why today’s Wearable Computing Is All Wrong


[Image by internets_diary on Flickr.]