http://www.livescience.com/scienceoffiction/070105_nanofabric.htmlSelf-cleaning fabrics could revolutionize the sport apparel industry. The technology, created by scientists working for the U.S. Air Force, has already been used to create t-shirts and underwear that can be worn hygenically for weeks without washing.
The new technology attaches nanoparticles to clothing fibers using microwaves. Then, chemicals that can repel water, oil and bacteria are directly bound to the nanoparticles. These two elements combine to create a protective coating on the fibers of the material.
This coating both kills bacteria, and forces liquids to bead and run off. [continued]
This reminds me of an old army joke: After living in the field for a week under the most primative conditions, the commanding officer decided to give his troops a break and allow a change of underwear. So he called the troops to attention and gave them the good news. "Men, in the interest of personal hygene, we are going to change our shorts today. Private Smith, change with Private Gonzales. Private Jones, change with Private Black..."