Weaving Batteries into Clothes

Oct. 9, 2007 — -- A novel machine that makes nanostructured fibers could be the key to a new generation of military uniforms that take on active functions such as generating and storing energy.

The fibers can be made of up to three different materials, arranged in regular, nanoscale patterns visible in cross section. The machine, manufactured by Hills, of West Melbourne, FL, is one of only two in the world capable of producing such fibers, says Stephen Fossey, a researcher at the U.S. Army Natick Soldier Research Development and Engineering Center, in Natick, MA. The machine is scheduled to be delivered early next year to the Natick facility, where it will serve as the centerpiece of a program geared to making multifunctional uniforms.

Among the machine's many potential uses is assembling fibers that act as rechargeable batteries. Angela Belcher, a professor of biological and chemical engineering at MIT, says that some of the sample structures the device has made could be useful for combining positive and negative battery electrodes and electrolytes into individual threads. Such threads could be woven into uniforms and paired with threads that act as fuel cells or photovoltaics.

The machine was featured last week as part of a workshop on wearable power held at the United States Army Research Laboratory, outside of Washington, DC. The workshop was part of a major push to develop better alternatives to today's batteries as foot soldiers come to depend more on electronic devices, from night-vision goggles and laser range finders to advanced radios and networked computers. Today, a typical platoon requires almost 900 batteries of up to seven different types for a five-day mission, says Charlene Mello, a member of the macromolecular-science team at the Natick soldier center. Besides being cumbersome to manage and carry, the batteries don't last very long, which could put soldiers in the position of having to change them in the middle of a fight.

What's needed are ways to store energy in less space and relieve soldiers of logistical burdens so that they can concentrate on their jobs, says Dave Schimmel, a project manager at the Natick facility who works with experimental technologies that are close to being tested in the field.