Imagine if you dropped your mobile device and didn't have to worry about breaking it, because you knew the phone would bounce harmlessly off the floor -- and, even if it were damaged, it could repair itself.
That's the promise of a new material developed by researchers at the IK4-CIDETEC Research Center in Spain that can fuse back together in two hours after being severed. The polymer-based material uses "a poly(urea-urethane) type composition, a material which is widely used in industry," the researchers said in a press release.
A YouTube video (below) shows a researcher cutting a solid cylindrical-shaped piece of the material in half. The two halves are put back in contact with each other and left to sit at room temperature for two hours. In that time, according to the video, the material connects back together as a single piece of polymer that doesn't separate when the researcher stretches it.
This catalyst-free healing occurs without any intervention or other material agents, the researchers wrote in a paper (registration required) published by the Royal Society of Chemistry journal Materials Horizons.
In the paper, the researchers discuss the key to the material's self-healing capability:
A particularly useful approach to generate self-healable polymers has been the introduction of reversible or exchangeable bonds into the polymer network. The idea behind this is to reconnect the chemical crosslinks which are broken when a material fractures, restoring the integrity of the material. This is expected to provide polymers with enhanced lifetime and resistance to fatigue. Self-healing approaches based on such dynamic crosslinks have been carried out using both reversible covalent chemistries and supramolecular interactions.
The self-healing polymer could have a wide range of applications in the commercial, industrial, and aerospace sectors, where damage to materials could be harmful not only to the device, but also life threatening.
I am writing a story now about this type of polymer being applied to battery design to help a battery self-heal cracks that appear over time during operation. I think this is a great application of this material: https://energy.stanford.edu/news/scientists-invent-self-healing-battery-electrode
Stay tuned for my story. It should post this week or next.
I've been wondering about that, too, Rob. Perhaps it could be adapted to prosthetics or other kinds of medical devices that people use so that if there ever is any kind of tear or malformation, it would fix itself without needing replacement. I wonder if any of our other readers can think of good medical applications for this?
As we've discussed before in DN, by definition a self-healing polymer is a single material that heals itself when damaged or broken. They are not adhesives that can be used to attach other materials together. We've covered self-healing and shape memory plastics before: http://www.designnews.com/document.asp?doc_id=267531 and see links at the end of that article.
That is an excellent question, John E. I don't know the answer--I think it is just a material that already has been attached. That's what I understand from the video and researchers. But if the two parts were made from the same material, I don't see why that couldn't work. It could be a really good application of the material.
There is currently much discussion around the term "platform," which may be preceded by the adjectives "mobile," "wearable," "medical," "healthcare," etc. However, regardless of the platform being discussed, they usually have one key aspect in common: They tend to be wireless. So, why is this one aspect so fairly universal? The answer is convenience.
Everyone has a MEMS story. For most of us it’s probably the airbag that saved our lives or the life of a loved one. Perhaps it’s the tire pressure sensor that alerted us about deflation before we were stranded alone on a dark muddy road.
Bioimimicry is not merely a helpful design tool -- it also encourages designers to think not only about how to solve design problems by imitating nature, but how to make the products, materials, and systems they design more ecologically sound and nature-friendly.
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