Medical Design and Outsourcing

What is nitinol and where is it used?

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A photo of nitinol, a nickel-titanium alloy used for medical devices such as stents, heart valves, catheters and orthopedics.

Nitinol — a nickel-titanium alloy — is used for medical devices such as stents, heart valves, catheters and orthopedics. [Photo via Adobe Stock]

Nitinol is a nearly equiatomic metal alloy of nickel and titanium with unique properties, including superelasticity (also called pseudoelasticity) and shape memory.

Superelasticity/pseudoelasticity means medical-grade nitinol shows great flexibility and elasticity under stress and can snap back to its original shape when pressure is released. 

Nitinol’s superelastic properties allow minimally invasive medical devices made with this alloy to compress to a lower profile for delivery via a catheter.

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Implants made from nitinol tubing or wire such as stents and replacement heart valves expand to their intended size and shape at the site of implantation and remain inside the patient, while nitinol therapy devices such as pulsed field ablation (PFA) catheters and renal denervation (RDN) systems expand inside the body, treat targeted tissue, and then compress again for retrieval.

Shape memory means medical-grade nitinol can remember its original shape and return to it when heated.

An image of Adona Medical's interatrial shunt and the induction catheter used for post-implantation adjustments.

Adona Medical’s interatrial shunt is adjusted after implantation using an induction catheter to heat the shape memory nitinol. [Illustration courtesy of Adona Medical]

One promising application of nitinol’s shape memory properties is under development by heart failure startup Adona Medical, which is working on a heart shunt device that can be adjusted for variable flow rates. Another is the investigational Myra Vision Calibreye shunt, which uses shape memory nitinol to make the device adjustable in an outpatient setting.

“With an increasing trend to treat patients using minimally invasive procedures, nitinol has become a popular choice of material due to its ability to return to its original shape after being mechanically deformed or after heat is applied,” the FDA said in a nitinol guidance document. “These properties are due to reversible transformations between the austenite and martensite phases, which may be temperature-induced (shape-memory) or stress-induced (pseudoelasticity). As a result, nitinol can withstand greater amounts of reversible deformations without plastic deformation than conventional metallic alloys, such as stainless steel, titanium, or cobalt-chrome alloys.”

Nitinol medical devices include cardiovascular implants, catheters for ablation and denervation, brain implants, devices for removing blood clots like those that cause strokes, and orthopedic implants. Nitinol is also used for dental products.

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Nitinol’s use in cardiovascular implants

A photo showing the Medtronic Harmony transcatheter pulmonary valve (TPV) squeezing into a thin catheter.

The shape memory properties of the nitinol wire struts in Medtronic’s Harmony transcatheter pulmonary valve (TPV) allow it to collapse down into a catheter for delivery and then expand inside a patient’s heart. [Photo courtesy of Medtronic]

Nitinol is used in many implantable cardiac devices, including catheter-delivered stents and replacement heart valves that can be placed using catheter delivery, such as Medtronic’s Harmony valve. Instead of using nitinol in its heart valve frame, the Edwards Lifesciences Sapien M3 transcatheter mitral valve replacement system uses a nitinol implant to anchor the valve.

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Structural heart surgical robotics startup Capstan Medical uses nitinol to expand and anchor the catheter-delivered mitral and tricuspid heart valves it’s developing. Nitinol can also be used for actuator wire in robotics.

Nitinol is also used in Abbott’s implantable clips to repair leaky heart valves, left atrial appendage occlusion (LAAO) devices, and CroíValve’s tricuspid valve repair implant.

A photo of the Cardiac Dimensions Carillon Mitral Contour System in a physician's hand.

The Cardiac Dimensions Carillon Mitral Contour System is made of nitinol for its superelasticity and shape memory properties. [Photo courtesy of Cardiac Dimensions]

One implant made almost entirely of nitinol — the Cardiac Dimensions Carillon Mitral Contour System — treats mitral valve regurgitation without actually touching the valve itself.

J&J MedTech’s V-Wave has developed an investigational interatrial shunt with nitinol for heart failure, while Heartpoint Global is developing a self-expanding pediatric stent.

Nitinol is commonly coated or wrapped with expanded polytetrafluoroethylene (ePTFE) for cardiovascular implants.

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Nitinol in therapeutic catheters

An illustration showing the Medtronic Sphere-360 in three shapes: pancake, sphere and linear.

The Affera Sphere-360 PFA catheter is adjustable, allowing the nitinol electrode to take different shapes inside a patient. [Image courtesy of Medtronic]

Nitinol allows cardiac ablation catheters to expand inside a patient’s heart for minimally invasive treatment of atrial fibrillation.

Pulse field ablation is the latest wave of these catheters, including PFA systems developed by Medtronic, Affera (purchased by Medtronic, these catheters use nitinol both to expand inside a patient’s heart and as electrodes for generating the energy fields), Boston Scientific, J&J MedTech, Abbott and Pulse Biosciences.

J&J MedTech radiofrequency (RF) and dual-energy (PFA and RF) ablation catheters use nitinol springs for contact-force sensing.

An illustration showing Flow Medical's novel delivery scaffold and its hollow nitinol tubing.

Flow Medical’s novel delivery scaffold uses hollow nitinol tubing to deliver clot-busting drugs. [Image courtesy of Flow Medical]

Nitinol is also used in renal denervation (RDN) systems that treat hypertension, such as Medtronic’s Symplicity Spyral self-expanding radiofrequency catheter and the needles that deliver alcohol in the investigational Ablative Solutions Peregrine catheter.

Startup Flow Medical is developing a minimally invasive system to treat pulmonary embolism with a novel nitinol scaffold that perforates blood clots and infuses them with tissue plasminogen activator (TPA), a thrombolytic drug commonly referred to as a clot-buster.

Nitinol medical devices in the brain

Wire mesh that has captured a blood clot

A blood clot captured by the Embotrap stent retriever [Photo courtesy of Johnson & Johnson MedTech]

Nitinol stent retrievers for thrombectomy — like the Johnson & Johnson MedTech Embotrap device — remove blood clots in ischemic stroke patients.

Startup Retriever Medical is developing thrombectomy technology that combines nitinol baskets with aspiration, clot-busting drugs and blood filtration for reinfusion.

Brain-computer interface (BCI) developer Synchron is testing catheter-placed nitinol implants in the brain to restore function to patients with paralysis.

Another potential neuro application of nitinol is a surgical robot prototype built at Boston Children’s Hospital for pediatric brain tumor procedures.

Other uses of nitinol in medical devices and systems

An illustration of the LimFlow System for Transcatheter Arterialization of Deep Veins, specifically the crossing stent that routes blood from the artery to the vein.

The LimFlow system’s self-expanding nitinol crossing stent diverts blood from a diseased tibial artery to a tibial vein to deliver oxygen to a patient’s ischemic foot. [Illustration courtesy of LimFlow]

Nitinol is used in a variety of catheters and implants such as orthopedic staples,

Nitinol enables peripheral intervention devices such as Inari Medical’s first-of-its-kind LimFlow system for avoiding amputations due to chronic limb-threatening ischemia. Inari Medical has also developed a nitinol-enabled thrombectomy system for acute limb ischemia.

Nitinol is also used in various colorectal surgery devices for reconnecting the intestine after a pathology is removed, and in oncology for wires that mark and locate breast tumors.

Alcon sells a nitinol implant to treat glaucoma in conjunction with cataract surgery.

Nitinol is being researched at MIT for dissolvable devices and at Harvard for mechanical actuation to fight muscle atrophy.

Nitinol for dental products and devices

Nitinol is used in dentistry, especially in orthodontics for wires and brackets that connect the teeth. SureSmile dental braces are an example of nitinol’s use in orthodontics. Nitinol’s also used in endodontics, mainly for cleaning and shaping root canals.

How did nitinol get its name?

The word “nitinol” comes from the atomic symbols for the metals nickel (Ni) and titanium (Ti) plus “NOL” for Naval Ordnance Laboratory. That’s the U.S. military explosives testing facility — now known as the Naval Surface Warfare Center — in White Oak, Maryland, where nitinol was developed. Fun fact: The former NOL facility in White Oak is now the FDA’s headquarters.

More nitinol know-how from Medical Design & Outsourcing:

Notable nitinol supply chain updates

Find more information about nitinol and other materials used for medical devices in our Medical Device Handbook.

This post was originally published in 2016 and most recently updated in July 2026.

About The Author

Jim Hammerand

Jim Hammerand is the managing editor of Arrowfly's Medical Design & Outsourcing, where he leads coverage of medtech innovation, design, engineering and manufacturing. He also reports breaking news at Arrowfly's MassDevice and contributes to our DeviceTalks podcasts and live events. Hammerand has more than two decades of journalism experience spanning newspapers, magazines, websites, live events, radio and TV news. For nearly a decade, Hammerand reported and edited business news for American City Business Journals as a reporter and digital editor at the Minneapolis/St. Paul Business Journal and then as managing editor of the Puget Sound Business Journal in Seattle. He holds degrees in journalism and management from the University of Minnesota and has won journalism awards from the Society of Professional Journalists, American Society of Business Publication Editors, and Trade, Association, Business Publications International. Connect with him on LinkedIn or by email at [email protected].

Comments

  1. MithilaG says

    Hi, I was curious to understand what the author’s take is on the current value of the Nitinol market within the medical device industry. Additionally, how would they estimate the growth rate of nitinol based devices?
    Many thanks and best regards,
    Mithila

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