Terminator-style robots are a step closer: Circuit boards that REPAIR themselves could lead to self-healing machines

Nanoengineers printed a self-healing circuit on the sleeve of a T-shirt and connected it with an LED light and a coin battery. The researchers then cut the circuit and the fabric it was printed on. At that point, the LED turned off. The secret behind the ink is its tiny microparticles oriented in a certain pattern by a strong magnetic field. Because of the way they are arranged, particles on both sides of a tear are magnetically attracted to one another, meaning a device printed with the ink can heal itself.