Tech + Engineering

09
May

Self-Healing Material Imitates Human Blood-Clotting System

A new material modeled off our own vast network of veins and arteries can “stitch” holes in itself as big as a centimeter in diameter.

While self-healing materials aren’t necessarily new, they’ve never been able to repair defects this large because the material would bleed out of the damaged area too quickly. But this new plastic is held in place because it quickly forms a gel, which doesn’t flow away as readily. The material could eventually find its way into a number of different applications, from spacecraft that need easily mendable parts to medical devices like hip replacements that correct for wear and tear over time.

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This time-lapse sequence shows a damaged sample going through the regeneration process. The red and blue dye show the two fluid streams of the new material, which come in contact with each other and eventually harden to fill the entire damaged region.

The key to the material is the two different chemicals, each in liquid form, that are stored throughout in separate but adjacent networks of vessel-like tubes. When they meet, a chemical reaction begins. Here’s James Morgan, writing for BBC Science:

A network of channels delivers a healing agent to the site of damage.

The chemicals arrive via two separate streams. They combine to seal the gap in a two-stage reaction. Initially, they form a gel scaffold across the hole. The gel then slowly hardens into a robust, solid structure.

“We filled regions exceeding 35mm within 20 minutes, and restored mechanical function within three hours,” the researchers wrote in Science.

Tests showed the material recovered about 62% of its original strength.

The material is still in its early stages, scientists caution, and it will likely require years of study before the material is truly usable. But with a prototype in place, scientists can now observe how the liquids will react when different types of damage occurs, such as tiny micro-fractures from repetitive stress instead of larger deformities from a strong single blows.

Scott White, leader of the study and professor at University of Illinois at Urbana–Champaign, explains the regenerative process.