Flexinol® - Frequently asked questions


What is Flexinol®?

Flexinol® (also known as Muscle Wire) is thin, highly processed strand of a nickel-titanium alloy called Nitinol - a type of Shape Memory Alloy that can assume radically different forms or “phases” at distinct temperatures. Flexinol come in eleven sizes and two transition temperatures: LT at 70°C (60°F) and HT at 90°C (200°F).

How do Flexinol® work?

At room temperature Flexinol® is easily stretched by a small force. However, when conducting an electric current, the wire heats and changes to a much harder form that returns to the “unstretched” shape the wire shortens in length with a usable amount of force.

How much do Flexinol® shorten?

Flexinol can be stretched by up to eight percent of their length and will recover fully, but only for a few cycles. But when used in the 3 to 5 percent range they can run for millions of cycles with very reliable performance. And, with active position feedback they can be held at any position along the contraction range.

How strong is Flexinol®?

Large wires are stronger than small ones, and strength varies with diameter. Our largest wire has 100 times the strength of the smallest size from 20 grams up to two kilograms — so you can easily match wire strength to your specific needs. In the table below, Recovery Force shows the force exerted by a wire when heated. The deformation force indicates the amount needed to stretch a wire when cool – about one sixth the forces exerted when the wire is heated.

What if I need more strength?

For more strength, use two or more wires in parallel. This gives you as much strength as needed, and still keeps the fast cycle times of smaller wires.

Flexinol characteristics