Extreme energy-dissipating materials are essential for a range of applications. The military and police force require ballistic armor to ensure the safety of their personnel. In contrast, 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.
The TSAM (Talin Shock Absorbing Materials) family of innovative protein-based materials is the first known instance of a SynBio (or synthetic biology) material that can deflect supersonic projectile impacts. This makes it possible to create advanced projectile capture materials and bulletproof armor to analyze the effects at extremely high speeds in space and the upper atmosphere (astrophysics).
Scientists used proteins that have evolved over millennia to enable adequate energy dissipation. They incorporated a recombinant form of the mechanosensitive protein talin into a monomeric unit. They crosslinked it, resulting in the production of the first reported example of a talin shock-absorbing material (TSAM).
Professor Ben Goult explained: “Our work on the protein talin, which is the cells natural shock absorber, has shown that this molecule contains 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 polymerised talin into a TSAM, we found the shock absorbing properties of talin monomers imparted the material with incredible properties.”
The team then used this hydrogel material to demonstrate the practical use of TSAMs by subjecting it to 1.5 km/s supersonic impacts, which is faster than the muzzle velocities of firearms, which typically range between 0.4 and 1.0 km/s, and the speed at which space debris impacts both natural and man-made objects. The scientists also found that TSAMs can preserve these projectiles after impact in addition to deflecting the impact of basalt particles (60 M in diameter) and larger pieces of aluminum shrapnel.
Most body armor used today is a bulky ceramic face with a fiber-reinforced composite backing. Additionally, while this armor is good at stopping bullets and flying debris, it is ineffective at stopping kinetic energy, which can cause physical trauma to the body beneath the armour.
Additionally, due to its reduced structural integrity, this armour frequently sustains permanent damage after a hit, barring continued usage. This makes the use of TSAMs in new armour designs a viable replacement for existing conventional technologies, offering a lighter, more durable armour shielding the wearer from a wider spectrum of injuries, including those brought on by shock.
In the aerospace industry, where energy-dissipating materials are required to efficiently collect space debris, space dust, and micrometeoroids for further scientific investigation, TSAMs are also useful since they can trap and store projectiles after impact.
These intercepted projectiles also aid in constructing expensive aerospace equipment, increasing astronauts’ durability and safety. Here, TSAMs might offer an alternative to aerogels, which are often used in the industry but are prone to melting due to temperature increases brought on by projectile impact.
Professor Jen Hiscock said: “This project arose from an interdisciplinary collaboration between fundamental biology, chemistry, and materials science which has resulted in the production of this amazing new class of materials. We are very excited about the potential translational possibilities of TSAMs to solve real-world problems. We are actively undertaking research into this with the support of new collaborators within the defense and aerospace sectors.”