Fiber Comprising Micro Devices and Metal Interconnects with Controlled Elasticity

An elastic and conductive fiber includes a cladding with a channel and a conductor disposed therein. The cladding may be made of a thermoplastic elastomer. The conductive fiber includes an excess length of conductor disposed inside of the channel so that the conductive fiber can stretch without applying substantial strain to the conductor and without substantially changing the electrical resistance of the conductive fiber. The conductor inside of the channel may have a buckled shape or a helical shape.