Shape of things to comeNew electronic fiber make smarter fabric a reality
A soft, flexible fiber with a 1,000 times more capacitance than a co-axial cable could lead to smarter textiles; these smart fabrics could sense their environment, store, transmit, and process information — as well as harvest and store the energy necessary to do all this
Good news for soldiers, first responders, athletes, the infirm, and others: The dream of a certain cadre of computer specialists to create smart textiles that can sense their environment, store, transmit, and process information — as well as harvest and store the energy necessary to do all this — appears a step closer.
A particular driver of this technology is the military which would very much like to remotely monitor the health and status of troops on the battlefield.
Technology Review reports that creating truly smart textiles is easier said than done. One problem is that clothing generally has to be soft and flexible, something that chips, wires and sensors usually are not. A second problem is that most clothing is made from woven materials which must be made from soft flexible strands (see “Aussie company creates the world’s first electronic underpants,” 29 March 2010 HSNW; “New fiber nanogenerators could lead to electric clothing,” 16 February 2010 HSNW; “Day of smart fabrics nears,” 8 December 2008 HSNW; and “The day of smart garments nears,” 5 July 2007 HSNW).
Some progress, though, has not been made. For example, certain conducting polymers can be drawn into fibers and woven into a material to form a kind of wearable motherboard. It is then possible to fasten electronic components such as chips, sensors and batteries to this motherboard.
This is a fiddly, time-consuming process, however. One thing that could help is more useful fibers — and Jian Feng Gu from École Polytechnique de Montréal, his supervisor, Professor Maksim Skorobogatiy, from the same institution, and a third colleague, Stephan Gorgutsa, reveal one reveal one that could help.
Their idea is to create a simple rolled capacitor from a sheet of conducting polymer sandwiched between two insulating sheets of low density polyethylene. They then roll this sandwich into a cylinder and encase it in high density polyethylene.
TR notes that there is nothing unusual about this kind of rolled capacitor, but what Gu and colleagues do next is unusual. They heat it and then extrude it through a tiny hole to form a fiber with a diameter of less than a millimeter.
If the conditions are just right, the plastics all stretch in exactly the same way so that the internal structure of the fiber is just a smaller version of the original.
This is exactly what happens. Gu and colleagues say their fiber is soft and flexible and has a capacitance some 1000 times greater than an equivalent co-axial cable. This could turn out to be handy. Gu and colleagues say that the capacitor should be able to store energy harvested by other devices such as piezo-electric fibers that might also be woven into a textile. By combining the capacitor with an inductor, it ought to possible to build all kinds of capacitor-inductor sensing circuits too.
This means that this fiber or something like it could turn out to be an important component of smart textiles in future.
—Read more in Jian Feng Gu, Stephan Gorgutsa, and Maksim Skorobogatiy, “Soft capacitor fibers using conductive polymers for electronic textiles,” arXiv:1006.5221v1 [physics.chem-ph] (27 Jun 2010)
