A revolutionary shock-absorption material that can stop supersonic impacts

The material is likely to be used in the developing advanced bullet-proof armor and projectile capture systems to "enable the study of hypervelocity impacts in space and the upper atmosphere (astrophysics)."

The focus of the research

The team focused on the protein talin, responsible for the cell's natural shock absorption capabilities. The study showed this molecule has a series of "binary switch domains which open under tension and refold again once tension drops." 

"This response to force gives talin its molecular shock-absorbing properties, protecting our cells from the effects of large force changes. When we polymerized talin into a TSAM, we found the shock-absorbing properties of talin monomers imparted the material with incredible properties," said Goult.

Why is it revolutionary?

The team tested the material to 1.5 km/s supersonic impacts and found that the hydrogel substance could withstand it. For reference, the tested figure is higher than the velocity of "particles in space impact both natural and man-made objects (typically > 1 km/s) and muzzle velocities from firearms – which commonly fall between 0.4-1.0 km/s."  

The properties of the hydrogel material could help advance bullet-proof jackets that are currently unable to block kinetic energy produced, resulting in behind-armor blunt force trauma. Also, TSAMs can help reduce weight and make such jackets reusable, as their structural integrity remains relatively unaffected after the impact. 

The material also has the properties to capture and preserve projectiles post-impact, making it useful in the aerospace sector, where "there is a need for energy dissipating materials to enable the effective collection of space debris, space dust and micrometeoroids for further scientific study."

Further applications could see TSAMs used in advancing aerospace equipment design by providing an alternative to industry standard aerogels, "which are liable to melt due to temperature elevation resulting from projectile impact." This will ensure the safety of astronauts and increase the lifespan of aerospace equipment. 

Abstract

Extreme energy dissipating materials are essential for a range of applications. The military and police force require ballistic armour to ensure the safety of their personnel, while the aerospace industry requires materials that enable the capture, preservation and study of hypervelocity projectiles. However, current industry standards display at least one inherent limitation. To resolve these limitations we have turned to nature, utilising proteins that have evolved over millennia to enable effective energy dissipation. Specifically, a recombinant form of the mechanosensitive protein talin was incorporated into a monomeric unit and crosslinked, resulting in the production of the first reported example of a talin shock absorbing material (TSAM). When subjected to 1.5 km/s supersonic shots, TSAMs were shown not only to absorb the impact, but to capture/preserve the projectile, making TSAMs the first reported protein material to achieve this.