Proteus is a light, strong and non-cuttable material that turns back the force of a cutting tool upon itself. The development of this new material was led by an international research team from Durham University, UK, and Fraunhofer Institute for Machine Tools and Forming Technology IWU in Chemnitz in Germany. The researchers got inspiration for this invention from the tough skin cellular skin of grapefruit and the fracture-resistant shells of mollusks.
Named after the shape-changing mythical god — Proteus is made of ceramic spheres encased in a cellular aluminum structure that could not be cut by angle grinders, drills, or high-pressure water jets during any testing stage.
When cut with an angle grinder or drill, the vibrations created by the ceramic spheres inside the casing dull the cutting disc or drill bit.
The interaction between the cutting apparatus and ceramic sphere creates an interlocking, vibrational connection that resists the cutting tool indefinitely.
Upon continuous applied force, the blade is gradually eroded, and eventually rendered ineffective as the force and energy of the drill is turned back on itself, and it is weakened and destroyed by its own attack.
Additionally, on the application of external force, the ceramics fragment into fine particles, which fill the cellular structure of the material and further harden as the speed of the cutting tool is increased due to interatomic forces between the ceramic grains. Hence, the adaptive nature of the material causes it to strengthen rather than wear down.
Most of the internal structure design and dynamic response of the material to external stimulus are inspired from living structures. To resist against the most violent forcible entry tools, organic materials such as aragonite tiles, which are found in mollusk shells, were replaced in the new material with industrial, alumina ceramics, and an aluminum, metallic foam matrix.
The researchers intend for the material to be used in bike locks, lightweight armor, and in protective equipment for people who work with cutting tools. However, there are many other applications that can be considered for this material.
The complete details of the invention and results of testing can be found in the Scientific Reports.