Metal-elastomer composite self-heals when damaged

Researchers have made a new breakthrough that could have significant implications for robots of the future. The breakthrough is a new metal-elastomer composite material that can self-heal and create new electrical connections that bypass damaged areas. The new material has uses outside of robotics as well with applications in stretchable circuits, soft machines, bio-inspired robots, and wearable electronics.

The material could mean wearable devices, for instance, that don't fail when mechanically damaged. The material is said to be analogous to the plasticity in nervous tissue, but researcher Carmel Majidi says that the team hasn't fully mimicked neuroplasticity with the material.

Prior to this research, the issue with soft and deformable circuits was that the soft structures easily tear, puncture, or mechanically fail. That means a loss in electrical conductivity rendering the circuits unusable. This new material is a soft silicon rubber embedded with micron-sized droplets of a gallium-indium based metal alloy that is a liquid at room temperature.

The circuits in the material are made with a pen plotter that ruptures the droplets and makes them into lines that are electrically conductive. Majidi says that the result is a mechanically compliant skin that is highly stretchable and as soft as natural skin. If a circuit trace is damaged, the liquid around the damaged area rupture and form new conductive pathways.

That allows the bypassing of the damaged area and re-routing of electrical signals without interruption. Researchers on the project have demonstrated the material in a self-repairing digital counter and a self-healing soft robotic quadruped that can function after severe damage. Researchers plan to engineer and study a soft conductive material that can self-heal both electrical and mechanical damage next.

SOURCE: Physicsworld