Self Healing Materials

Sneak peak at images inside excellent paper reviewing self repairing materials. Click on link for a deep dive!

I’ve recently become more obsessed with self healing materials, which I have learned in materials science speak is “autonomous material systems”. I like that fancy title, in one part for it’s scienceness factor, but mostly because it reminds us that materials are complex systems, not a static substance. To get started I’ve included the Wikipedia definition is here (which has an excellent overview of the general research):

Self-healing materials are a class of smart materials that have the structurally incorporated ability to repair damage caused by mechanical usage over time. The inspiration comes from biological systems, which have the ability to heal after being wounded.

Below I’ve collected a variety of case studies and a general overview of some of the principles. If you’re ready to dive into the meat of the science there is a paper available here that really shows off the research.

Autonomous Materials Systems

The best site for an overview of the science as well as mind blowing examples of the materials research  is the Autonomous Materials Systems website from the Beckman Institute for Advanced Science and Technology at the University of Illinois at Urbana-Champaign (whew that’s a mouthful).

The materials are incredible. Their research presents three main types of self healing materials;

  • Microencapsulated Systems – material containing little capsules filled with a healing agent that bonds when in contact with catalysts also embedded in the material (see diagram below).
  • Microvascular Systems – materials filled with capillaries filled with healing agents
  • Mechanoresponsive Polymers – modifications made at the chemical level that control how a material responds under strain – simple example is changing colour before failure. I’ll admit I understand this kind the least.
Wikipedia has a more complex break down, but I think the above categories work well for me.

Image by Carl Hastrich - modified from Beckman Institute for Advanced Science and Technology: Pop a couple of capsules, connect to a catalyst and done! Simple as that.

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