The engineers took inspiration from seashells and grapefruit to create what they say is the first non-cutting material ever made. This new material, which can be used in the health and safety industry, can wrap the power of a cutting tool on itself. The development was presented in Scientific reports.
The lightweight material – named Proteus after the mythical god Proteus, who could take on various forms – is made of ceramic spheres enclosed in a honeycomb aluminum structure. During the tests, it cannot be cut by angle grinders, drills, or high-pressure water jets.
An international research team led by the University of Durham in the UK and the J. Fraunhofer in Chemnitz, Germany, got an idea for a new material made from the tough cell wall of grapefruit and the break-resistant shells of shellfish.
These sea creatures are built from tiles bonded with a biopolymer material that makes them fracture resistant. The organic materials that protect the shellfish – such as the aragonite tiles found in their shells – have been replaced in the new material with industrial, alumina ceramic, and aluminum metal foam matrix.
The new material is durable, lightweight, and does not cut. Researchers say it can be used to make bicycle locks, light armor, and protective gear for people who work with cutting tools.
The new material system is dynamic with an evolving internal structure that creates high-speed motion where it interacts with cutting tools. The dynamic response is more like living structures.
The material is made of a honeycomb aluminum structure wrapped around ceramic spheres, which has a double destructive effect on cutting tools. When cutting with an angle grinder or drill, the vibrations generated by the ceramic balls inside the body blunt the blade or drill.
The interaction between the disc and the ceramic sphere creates an interlocking vibration link that resists the cutting tool endlessly. The blade gradually collapses and ultimately becomes ineffective as the force and energy of the disc or drill is turned back on itself and it is weakened and destroyed by its own attack.
In addition, the ceramic breaks down into small particles that fill the cellular structure of the material and harden with an increase in the speed of the cutting tool due to the interatomic forces between the ceramic grains. Thus, the adaptive nature of the material additionally repels any impact.
We were intrigued by how the cell structure of grapefruit and the tiled structure of shellfish shells can prevent damage to the fruit or creatures inside, despite being made from relatively weak organic building blocks. Basically, slicing up our material is like slicing jelly filled with nuggets. If you try jelly, you hit nuggets and the material will vibrate in a way that destroys the blade or drill.
Stefan Shinishevsky, Associate Professor, Department of Applied Mechanics, Department of Engineering, University of Durham
These natural structures determined the principle of operation of the cermet material, which is based on dynamic interaction with an applied load, as opposed to passive resistance.
The researchers have acquired a patent for their technology, and they hope to strike deals with industry partners so that it can be turned into products for the market.