Self-reparing plastic
From Conworld
Status: UNKNOWN / PENDING DISCUSSION
// Ketsu Drop a MsgAlex 08:31, 23 July 2007 (EDT)
Contents |
Current Status of this Technology
Layman Explanation
University of Illinois at Urbana-Champaign have made a polymer material that can heal itself repeatedly when it cracks. This is significant as this is the only technology that heals itself WITHOUT OUT INTERVENTION, unlike previously designed materials rolled out by the same lab.
The researchers are able to crack and reheal the surface as many as seven times (AT HIGH HEAT AND PRESSURE) before the catalyst wears out and stops working. The next generation of the self-healing material should be able to heal itself many more times, according to the researchers. Sottos and her colleagues are designing it so that it will have a two-part system that injects both a healing agent and a catalyst into the crack.
Ketsu Explanation
Modeled on human skin, the new material that heals itself multiple times is made of two layers. The polymer coating on top contains tiny catalyst pieces scattered throughout. The substrate contains a network of microchannels carrying a liquid healing agent. When the coating cracks, the cracks spread downward and reach the underlying channels, which ooze out healing agent. The agent mixes with the catalyst and forms a polymer, filling in the cracks.
The researchers could also increase the rehealing capacity of the material by hooking up the microchannel network to a little reservoir, Sottos says. If the material runs out of healing agent or catalyst, the reservoir could pump in more.
The material's microchannel design could be a solution to the increasing problem of heat buildup in microelectronics chips. Typically, microelectronic circuit chips sit on substrates that are designed to conduct heat away from the circuit. These heat regulators have their limits. Instead, Sottos says, "you could put a cooling fluid through a microchannel network like a little mini-heat exchanger."
Sottos says that researchers could use the same design with other resin and catalyst combinations that can form different polymers. This opens the door for many other applications. While practical self-healing materials might be years away, it's easy to imagine their applications in prosthetics and medical implants made from biocompatible self-healing materials. The cost of the materials might keep them limited, at least initially, to certain high-value, high-performance applications such as use in air- and spacecraft, says Ian Bond, aerospace engineering professor at the University of Bristol, in the United Kingdom.
In the future, different chemistries could lead to cheaper self-healing materials, according to Bielawski. "You could use cheap epoxies ... that you can buy at Home Depot ... as a healing agent," he says.
Future implementation
// You decide... self-healing spacecraft?
