This material, which is also called viscoelastic foam, was developed by NASA then reverse-engineered and popularized by the Swedish. It is most frequently found in Tempurpedic™ mattresses and pillows. William Gibson mentions it several times in his novel Count Zero. It is considered by many people to be very comfortable, and it is an ideal resting surface for people that are in the same seat, bed, or wheelchair for extended periods of time.
Properties
The most noteworthy property of this material is a shape-memory effect similar to the metal alloy nitinol. The glass transition temperature of the foam is close to human body temperature. When a person lays down on it, they deform it. As their body warms it up, the material is heated above its glass transition temperature and a restoring force attempts to push it back to its original shape. This accounts for the excellent weight distribution and comfort felt on pillows, mattresses, and upholstery made from that material. It is also quite flame resistant and shock absorbent, which is why it has a great deal of appeal for aerospace applications.
Composition
It is composed of a blend, or possibly a copolymer, of polyurethane and silicone rubber. The exact composition is proprietary, as are the processing techniques that form its open-cell foam pore structure.
Applications
- Aircraft upholstery
- Medical upholstery
- Padding for helmets and sports equipment
- High end pillows, office chairs, and mattresses
Developers
- Charles Kubokama
- Charles J. Laenger
- Sam McFarland
- Robert L. Willbur
- Charles A. Yost
History
It was developed in the late 1960s and early 1970s for use in aircraft seats. Some say that it was originally developed to protect test pilots, while others claim that it was developed to help astronauts deal with the forces that they would experience during takeoff. In 1998, it was inducted into the U.S. Space Foundation's Space Technology Hall of Fame.
Web Reference
http://www.tempurpedic.com