Is Self Healing of a Material is possible???
Can a material could heal itself ? sounds phony ? then not,the self healing material do exist and the automisation of self healing is on its final stage.Think of a world with bikes,cars and all which automatically repairs its body on a crack..mmmm really interesting right.
The present developed self healing material is a boat say a yacht which won two America’s cup named Alinghi.What make it self healing is a carbon fiber composite with which its hull is made of.it could heal itself following a collision.But the automatic self healing is not achieved,But a EPFL graduate student discovered that it could be healed easily by passing electricity .Lets look how it works….
This carbon fiber composite is made of many layers of light weight carbon fibers and epoxy resins which offers much higher strength to weight ratio of materials with similar weight.And we use this material in the manufacture of racing cars ,Boeing planes etc in large percentage to make it light weight and strong.But this material has got a disadvantage that it has a tendency to get separated or to cause a cleavage/crack in the lamination during huge impacts.So studies where done to rectify this and as result ,self healing carbon composite was born.
How the carbon composite becomes self healing.To achieve this the carbon composite is impregnated with small droplets of bubble with self healing liquid monomer in it and smaller amount catalyst which could harden the monomer at the time of healing.At the time of impact some of the bubbles rupture and releases the monomer along with the catalyst causing the hardening of monomer in the damaged part.But the problem with this is that to keep the carbon material strong enough the density of bubble shoud be low and it may result in the lack of monomer during a crack.
So the graduate student Eva Kirby found a new way,she incorporated certain wires known as shape memory alloy(SMA) along with the carbon composite.The property of this wire is that it would retain its shape by the passage of electricity through it, even if it is in a deformed state.So if we could pass electricity at the time of a crack through the SMA wires on the surface of composite, it would regain its shape and would reduce the area of crack so that even small amount of monomer bubbles could fill the gap.
But how could we know where the crack had occurred to pass the electricity.She came with a remedy for this problem too, she added optic fibers along with the SMA wires so that when ever a bent or crack occurs it interrupt the light propagation and could detect the area easily using a monitoring system.And we could pass electricity to that area.More research studies are going on this automation process.
So tomorrow this idea could make a revolution to new world ,its application area is much more than we could think,a plane with automatic repairing wings,a house with self healing capacities on cracks,cars and bikes even without a scratch.Really amazing the world of technology,isn’t it?????…..