What type of material is Nitinol?

Nitinol is a metal alloy of nickel and titanium with unique properties, including superelasticity or pseudoelasticity and “shape memory” properties. That means nitinol can remember its original shape and return to it when heated. It also shows great elasticity under stress.

What are shape memory polymers examples?

Typical examples of polymers which can exhibit this shape memory effect include (meth)acrylates, polyurethanes, and blends of polyurethane and polyvinylchloride.

What are shape memory polymers made of?

The shape-memory polymer network consists of covalent netpoints and switching segments based on a physical interaction. To display shape-memory functionality, the polymer network has to be temporarily fixed in a deformed state under environmental conditions relevant to the particular application.

What is the difference between a shape memory alloys and polymers?

Shape-memory polymers differ from shape memory alloys (SMAs) by their glass transition or melting transition from a hard to a soft phase which is responsible for the shape-memory effect. In shape-memory alloys martensitic/austenitic transitions are responsible for the shape-memory effect.

Is Nitinol a biomaterial?

Nickel-titanium alloy (Nitinol) is a metallic biomaterial that has a unique thermal shape memory, superelasticity, and high damping properties. Nitinol is potentially very useful in orthopedic surgery, for example.

Is Nitinol an alloy?

Nitinol was developed by the U.S. Navy and stands for nickel titanium alloy. This metal is particularly useful for medical applications because it has thermal memory. This property allows stents to be made at a certain diameter, cooled, and then compressed onto a delivery system.

What is shape memory composite?

Shape memory composites (SMCs) are attractive materials as they combine typical mechanical and functional properties of composites with shape memory properties. Such properties can be given to composite materials and structures by using shape memory polymer (SMP) matrices or integrating parts made of SMPs.

What stimulus is required to return nitinol to its set shape?

Nitinol is a shape memory alloy, a mixture of two types of metal (in this case nickel and titanium) that will bend but will return to its original shape when heated.

How are shape memory polymers manufactured?

These objects are built by repeatedly extruding thin layers of molten materials through a nozzle in different paths and depositing these layers until the desired object is formed. The shapes are defined by a computer aided design file.

What name is given to alloys like Nitinol?

Nickel titanium, also known as Nitinol, is a metal alloy of nickel and titanium, where the two elements are present in roughly equal atomic percentages. Different alloys are named according to the weight percentage of nickel; e.g., Nitinol 55 and Nitinol 60.

Can polymers change shape?

A shape memory polymer can change from a temporary shape that is achieved by deforming it, to a previous shape which is its permanent shape when it is not being deformed.

How is Nitinol manufactured?

Virtually all Nitinol components go through a similar series of basic manufacturing steps. To produce the basic material forms, such as wire, tubing, ribbon, sheet and bar, Nitinol materials are vacuum-melted, hot-worked, cold-worked and then heat-treated to achieve final properties.