Milford instruments flexinol muscle wires milford instruments 3r071 flexinol wires are highly processed strands of a nickel titanium alloy called national at room temperatures flexion wires are easily stretched by a small force when heated e g by a small electric current the wire shortens with a useable amount of force flexinol wires contract by 3 to 5 irrespective of gauge size and require typically 0 3v cm length milford instruments flexinol wire 100um x 1m