Nickel-titanium alloy, also known as memory alloy, is a kind of functional metal material. This kind of alloy has the ability to remember the shape and restore the original shape under certain conditions. Being mainly used in transportation and household appliances, the main function is as actuators and sensors. Under efficient operation, the physical space of the product can be reduced, and the product life can be extended.

It has both shape memory properties and super elastic properties. It is widely used as a material for medical devices such as stents and guide wires in the treatment of vascular diseases such as myocardial infarction and cerebral infarction in the medical field. The characteristic of being able to return to the original shape and the characteristic of softness (super elasticity) even after large deformation, it has made a great contribution to the minimally invasive treatment that reduces the burden on the patient's body.