Developments to Watch
A SHOCK-ABSORBING CERAMIC THAT ACTS LIKE BONE
Today, most bone-replacement surgery uses titanium or other metals. Ceramics more closely mimic bone, but they are too brittle to last and must be manufactured at very high temperatures. Now, Samuel I. Stupp, a professor of materials science at the University of Illinois at Urbana-Champaign, has synthesized a new class of ceramic composites that could solve these problems, making them usable as bone replacements, as well as in microelectronic devices and car engines.
Stupp's idea is to trap threads of polymers--chains of carbon-containing molecules--within the crystalline structure of ceramics as they are being manufactured. These so-called organoceramics are much less likely to crack under pressure than ordinary ceramics. The polymer acts as a cushion of sorts, allowing the ceramic to better absorb stress. Moreover, the material can be formed at room temperature.
Organoceramics already exist in nature: Dental enamel, bones, and sea shells are all examples. With that in mind, Stupp has synthesized an organoceramic leg bone that has lasted six months so far in dogs with no signs of deterioration.EDITED BY WILLIAM D. MARBACH