Climate adapting jacket works like a pine cone

'Smart' Clothing Imitate Pine Cones

When pine cones fall from the trees, their scales open, allowing the seeds to be released. This is because these scales are made of two layers of fibers acting in different directions. Stealing this idea from nature, a team of U.K. researchers has designed a new material to make 'smart' clothing which adapts itself to changing temperatures. Like the scales of pine codes, this 'smart' material has two layers. The top one has small spikes, which open or close to let the outside air flow to cool you or to protect you. And as the second layer is waterproof, you should always feel comfortable wearing these clothes imitating nature.

Current commercial applications of climate-controlled clothing operate using fibers designed to stretch or curl in a certain direction when heated. Manufacturers can create fabric that adapts itself to weather conditions by overlaying clothing with many tiny strips of these fibers; the clothing can become cooler in warm weather and warmer in cold weather.

When the fabric is heated up, the strips curl outward, increasing airflow throughout the clothing. Conversely, when the fabric is cooled, the strips straighten out and form a solid layer, preventing loss of heat and moisture. These fabrics have proven invaluable for activities that involve changing temperatures, including mountain climbing and skiing.
Read more at: http://www.thetartan.org/2008/3/24/scitech/htw