As if the idea of Terminators isn’t scary enough we are now finding ways for them to self-heal. Nancy Sottos, an engineer at the University of Illinois at Urbana-Champaign has created a new plastic that “bleeds” when it is cut or cracks and then heals itself. The plastic is based on our own body’s ability to heal itself. Our bodies are laced with veins, capillaries and other fun stuff that deliver whatever is needed to the site of the injury to help mend it.
Sottos made headline in 2001 for the creation of a healing plastic the used microcapsules filled with liquid resin that were located within the plastic. If the plastic cracked or was cut some of the microcapsules would rupture oozing the liquid resin into the damaged area then hardening. But that wasn’t good enough, now she has created materials that have their own microvascular systems that are filled with healing fluids. Some of the channels within the plastic are filled with a liquid resin while others are filled with a curing agent. When cracked it causes the channels that it has broken open to spill their contents into the crack then the curing agent mixes with the liquid resin and forms a hard epoxy that then fills in the crack, fixing that which was broken. The plastic can be broken multiple times but re-heal each time. The liquids can also be replaced should they begin to run out.
The idea is that with this technology we may be able to stop catastrophes before they happen. Normally when a man-made structure fails it doesn’t just sudden stop working or fall apart. It happens over time, caused by a small crack that goes unnoticed and eventually weakens the entire structure.
Sotto has created so far self-healing hard plastics and foam and has also created a plastic that pumps the healing liquid directly to the injury, like our own circulatory systems.
Using this microvascular system, Sottos has demonstrated how engineers could lower the temperature of materials by putting water into the channels rather than the healing liquid. This method could eventually be used to make computer chips and other electronics that can monitor and control their own temperature.
But Nancy Sottos isn’t the only working on such things. Marek Urban, a polymer scientist at the University of Southern Mississippi in Hattiesburg, and his team have created a self-healing latex that turns red when damaged, much like the blood from a scratch on real skin. Unlike the plastic created by Nancy Sottos, however, Urban’s creation must be placed in sunlight before it can heal.
Nissan announced earlier this year that they are working on self-healing iPhone cases. The paint being used on the cases is made with Polyrotaxane, which is special because it’s chemical structure has the ability to change back into its original form and filling in all the nooks and crannies within the damaged area, thus healing itself.