SMART Tire Co . Using Titanium Wire To, Quite Literally, Reinvent the Wheel

By Michael C. Gabriele

Some might say that the SMART Tire Group is using titanium wire to “reinvent the wheel.” However, in this case, the expression fits and is an accurate description of a company’s research and development efforts, not just a hackneyed phrase.

Now, as the company sets its sights on the rollout of the near-term commercial production of its Shape Memory Alloy Radial Technology (SMART) concept, titanium tires have the potential for applications that span wheels for cars, motorcycles, trucks and aerospace vehicles. The technology also is slated to be used for wheels to drive NASA’s Fetch rover headed to Mars in 2026.

The Los Angeles-based company is gearing up its SMART technology for the commercial introduction of its METL™ bicycle tire made from the super-elastic nickel/titanium Nitinol, according to information posted on the SMART Tire website (www. smarttirecompany.com).

Brian Yennie, SMART Tire cofounder and chief technology officer (along with Earl Cole, co-founder and chief executive officer), explained that super-elastic Nitinol “is the only shape memory alloy suitable for this type of large scale structural application. While other shapememory alloys (SMAs) exist, none are well suited for the variety of forces present in a tire. For example, copperbased SMAs are too brittle and would quickly fail in the form of a radial arc. While Nitinol is not new, most prior work is either in the micro sizes (heart stents/biomedical) or actuator applications (as opposed to superelastic). Accurately modeling large scale SMA structures is a brand new field, and we’re not aware of anyone outside of NASA and SMART doing that kind of work.”

Titanium Tire Prototype

SMART Tire Co.

Fort Wayne Metal’s Nitinol

Information posted on the Fort Wayne Metals website (www. fwmetals.com) touts Nitinol as “an alloy like no other.” The online product information states that Nitinol offers super-elastic and shape memory properties—the ability to remember and return to a specified shape after deformation when exposed to a predetermined temperature. There are two primary types of Nitinol: super-elastic and shape memory, which are determined by transformation temperature. “Super-elastic Nitinol is cooler, and shape memory Nitinol is warmer. Don’t let the description fool you; the same super-elastic and shape memory effect is taking place regardless of category,” according to Fort Wayne Metals.

Yennie said SMART Tire is working with titanium wire producer Fort Wayne Metals as its material supplier. As for the production method, he said the tires are woven from a variety of Nitinol wire and spring elements. “This is currently a manual process but we are refining the design and developing new manufacturing methods to scale production,” he said. “Currently we do everything in-house, with components provided by Fort Wayne Metals. As we move towards a final product, we may incorporate components from other suppliers and expect to open new facilities near Cleveland.”

NASA and Fort Wayne Metals provided cutting-edge research in shape-memory alloys, and we consider them to be the world leaders,” he continued. “Developing Nitinol wire to meet extreme and custom requirements is a strength of theirs and critical to our work.” Yennie explained that SMART Tire’s titanium needs are specialized. “As we move into higher volumes of product in coming years, we will be looking to significantly grow our supply chain. A popular automotive tire, for example, would require a very substantial amount of titanium to meet demand, many times the current volume of Nitinol being produced. We believe as more large-scale structural applications of shape-memory alloys emerge, the whole industry will follow.”

Plans for METL Bicycle

SMART Tire is expected to unveil a market-ready METL bicycle tire by the third quarter of 2022. The METL tire is the company’s “beachhead” product to establish itself in the market, “and you can expect that to scale out to multiple 2-wheel applications, as well as most segments of the cycling market,” Yennie said. “We are pursuing multiple other product lines, but have no announcements at this time. I can say that there is considerable interest in the technology across all the vertical (transportation markets). The company website indicates that SMART is being pitched as a revolutionary technology for the $250-bilion global market for tires. “This represents the estimated global market for all tires, though these estimates vary and may be understated. Compound annual growth rate has been around 5 percent for the overall market, but is twice that in the two-wheel segments (bicycles, scooters and motorcycles).”

Reports of an unfolding global market expansion for bicycles look to be a case of good timing to coincide with the company’s near-term business plans. Various news wire stories predict an annual growth rate of 4 to 7 percent for the global bicycle market, which is described as highly fragmented and subject to regional trends. Growth factors include interest in new e-bikes and a focus on personal health and outdoor recreational activities, as countries emerge from the Covid-19 lockdown restrictions.

Riding on the Martian Landscape

NASA programs originally developed the concept and technology for super-elastic Nitinol tires for research vehicles delivered to Mars, where they would need to survive the unforgiving, rocky Martian landscape, where extreme temperatures can drop to -148˚F. Airless and tubeless, the tires can bend like rubber, air-filled pneumatic tires, but return to their original shape due to Nitinol’s shape-memory properties and never go flat.

Yennie and Cole connected with NASA in the spring of 2020 as part of the FedTech program at the Glenn Research Center, located in Cleveland. The SMART program had been under development at the Glenn Research Center for more than seven years. Yennie and Cole worked with inventors Dr. Santo Padula and Colin Creager in order to realize the commercial applications for SMART. “Earl and I were recruited into the FedTech program,” Yennie recalled. “We researched the full NASA patent portfolio to determine if there was a technology worth pursuing and agreed that the tire technology was by far the most promising, and our inspiration to participate in the program.”

“We conducted dozens of customer interviews, picked the brains of the inventors on a weekly basis, performed market analysis, and ultimately landed on the METL concept as part of a full commercialization plan for terrestrial use of shape-memory alloy tires. After licensing the portfolio from NASA and incorporating SMART Tire last year, we spent the next six months building strategic partnerships and growing our team, which led up to our big unveiling this March. METL obviously struck a chord, as we were quickly picked up by TechCrunch, Mashable, Gizmodo, and several cycling outlets (such as Bike Rumor, Pink Bike, Bicycling Magazine, Triathlete).”

As mentioned above, the SMART tire will be used as the wheels for NASA’s Fetch rover mission, which is expect to land on Mars in 2028.

METL Bicycle

SMART Tire Co.