Will Your Next Whip Pack Memory Chainmail Tires?

NASA’s Glenn Research Center is experimenting with nickel-titanium memory alloy tires that resemble chain mail. It’s an intriguing angle — the tires can withstand heavier loads and at higher speeds. They’re airless and immune to puncture. Presumably they’re not literally chainmail but closer to a sweater in construction.

This tire is a culmination of a number of fascinating research drives. NASA has been experimenting with tensegrity structures as a means of building in space without spending a ton of rocket fuel on heavy hardware. These structures use tensioned cables to maintain a three-dimensional structure. The tires use the stiffness of the wire as well as internal stiffeners to maintain shape, without the need for a whole rim.

In addition to structural tensegrity, the memory alloy also helps keep its original shape by resisting deformation — it springs back into its original shape. When ordinary materials are stretched, you’re stretching the bonds between the atomic structures. NASA’s NiTi alloy goes through an “atomic rearrangement” when stressed, easing the forces put on those structures. As a result, the alloy can withstand 10% deformation versus 0.3% for spring steels, or about 30 times the deformation that a normal alloy could withstand without having permanent deformation occur — dents, basically. NASA’s tires can actually compress down to the axle and then pop back.

Another advantage of the configuration is that traction and stiffness can be modified to tailor the tires to specific environments — just change the tension put on the radial stiffeners to make them harder or mushier. This, as well as the alloy’s deformation resistance, makes them adept at rolling over rocks without suffering damage; this has been a problem with Mars Rovers.

NASA has patented the technology — they call it their superelastic tire — and they claim they could be useful in the private sector. Are you ready for memory alloy skateboard wheels?

Want to know more about how tires are made here on earth? Check out this Retrotechtacular about a classic tire factory. You can also build custom sticky tires for your sumo robot.

[Thanks, Steve!]

37 thoughts on “Will Your Next Whip Pack Memory Chainmail Tires?

    1. Seems they think it can work, I quote:

      Benefits
      Safe: Eliminates the possibility of puncture failure
      Strong: Can withstand excessive deformation
      Robust: Can be configured for high traction on various terrains
      Simple: Eliminates the need for air
      Versatile: Tire stiffness can be designed to limit energy transferred to vehicle
      Lightweight: No inner frame needed for the tire/wheel assembly

      Applications:
      All-terrain vehicle tires
      Military vehicle tires
      Construction vehicle tires
      Automobile tires
      Heavy equipment tires
      Agricultural vehicle tires
      Aircraft tires

      That last one has me a bit surprised, for aircraft you need ability to take a lot of impact and speed.

    1. These chainmails aren’t exactly airtight though. And for robust airtight stuff they got aramids.
      But for robot bumpers these tires in a smaller form might work, pliable but tough, could prevent damage from robots to space structures maybe, put half-circles on the side of their joints.

    1. Don’t think gum last long on a freeway, however you got a point, but perhaps for public roads you could just skin them with a thin tough pliable substance, you’d still retain most benefits. The material would need to be able to withstand miles of road though while being pretty flexible and thin.

  1. It’s obviously meant for slow movement on rocky terrain, and the traction on asphalt would be terrible compared to rubber tires, but that’s not what it’s designed for.

    I do wonder how it would deal with little rocks getting stuck in the mesh, causing local abrasion and everything wearing through the wires. Round wires that bend a lot generally break very quickly when nicked or scratched.

  2. This is basically just an evolution of the original wheels used in the LRV.

    Personally, I’m suprised they haven’t trialled the airlesss wheels that came out for humvees a couple of years back:

    1. Those are made of plastics, which will not be very…plastic… in extreme cold (like you’d find on Mars…). Similarly, they will be a little too plastic at high temperatures.

  3. What this design could be great for is as an underlying structure for a rubber tire…using this arrangement to replace the cords and belts and sidewall rings. The ability to support a vehicle without air would be very useful in offroad racing, both for “crawling” performance and as a survivability feature.

  4. I’m sure I’m just missing something – but why would I need chain mail tyres on my whip?

    On my car, bike, scooter, skateboard maybe but when I get my whip out I don’t want it going anywhere!

  5. It looks like a great way to save weight, and I think they may work well for the designed purpose. As for on road use you have two very major problem to deal with.
    1. the alloy will wear quickly, very quickly, but even if that is solved, the second problem is bigger,
    2. traction, friction is significant between rubber and tarmac, which allows for aggressive braking when needed, this will slide. and be much worse on ice.

    This might be able to be fixed by adding a layer of rubber on the outside, but the amount needed would negate a lot of the weight savings, and it’s likely that this still would not be able to be used by the vehicles that need weight savings the most: large trucks (lorries), and 1 to 3 ton trucks that need load range “E” tires (10 ply)

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