Nitinol tire

Nitinol Is A Material We Need To Be Playing With More

Another Kickstarter, another opportunity for people to get mad at delayed and poorly functioning (if delivered at all) gadgets. This project aims to make airless tires for bikes and scooters using nitinol, and despite the company’s failed attempt at pedaling their wares on Shark Tank last year, the campaign has already more than quadrupled its funding goal.

The real star of the show here is NiTinol, a shape metal alloy composed of nickel and titanium. We should soon see a real commercial application of this miracle metal, and not long after we’ll see what happens when the rubber meets the road on these airless tires and their long-term performance. It’s not accurate to say they don’t use rubber; they just use LESS, because they’re still treaded, albeit with a layer that is adhered to the metal coil, and you don’t need tubes, either. The tread will still wear down and needs to be replaced occasionally for the lifetime of the tire, but the real advantage is never having a flat tire again. Considering how inconvenient flats are and the number of meetings I’ve been late commuting to because of an unplanned rapid deflation, these tires might be worth it. If you’re wondering why they’re so expensive, some napkin calculations of the nitinol coil have somewhere between 100 ft – 200 ft of wire per wheel, and at $1-2/ft, the raw materials alone before assembly make it an expensive piece of kit.

So what’s so cool about nitinol that it’s worth playing with, and what does it do that spring steel or stainless steel can’t? Well, you can soak it in acid for a year, and it will continue unaffected. It has excellent bio-compatibility, so you can put it in someone’s arteries as a stent, and it will go through tens of millions of cycles without cracking. It’s 10 times better at recovery and lighter, and it’s not magnetic, which can be useful. The memory capability is handy, too, because it means you can rapidly prototype springs, then heat and quench them to set their memory and easily adjust them.

Admittedly, I don’t have a use for it right now. But just like the coils of nichrome and piano wire waiting anxiously in my bins for their opportunity to shine, nitinol is screaming for a fun use.

Making A Nitinol Wire Inchworm

[Steven’s] at it again with another cool science experiment that isn’t too difficult to do. This time he’s made himself a Nitinol wire inchworm, which actually moves across the table when you apply a switching electrical current to it!

Nitinol is a shape memory alloy which has a cool property that causes it to retain (and return to) a preset shape when heat (or electricity!) is applied. It’s actually quite simple — he’s wrapped the Nitinol wire tightly around a nail, and then heated it to set it to a coiled shape. Now the Nitinol spring can be stretched out flat, but as soon as it is heated, it will attempt to return to its coiled state!

Using some balsa wood and a few other odds and ends he’s taken advantage of this memory effect to make an electric inchworm — check it out after the break!

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Floreo: E-textililes And Moving Clothing

pedul [Alica] and [Jerika] are seniors in the Digital Culture program at Arizona State University and for their capstone, the wanted to take something that is traditionally male dominated and make it more female friendly. They chose e-textiles, which are most commonly extremely avant garde and nearly unapproachable with a lot of LEDs and zany mechanisms. Their initial designs reflected this, with multiple LED strips and huge shoulder pads. Then they discovered Flexinol shape memory actuator wire, and found this could be a much ‘softer’ integration of technology with haute couture.

[Jerika] and [Alica] chose to create an electronic flower, able to bloom with the help of a shape memory alloy. When a current is applied to the Flexinol wire, it contracts. Sewing these wires into laser cut fabric petals, the girls created a fabric flower that booms with the help of an LiliPad Arduino.

While they weren’t able to complete their dress due to electronic weirdness and burning out the wire too soon, they did succeed in creating a flower pin that demonstrated the intended effect.

Videos below.

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Animated Paper

What if you could make paper react on physical input. Maybe you want it to shy away and close up if someone reaches for it too fast, or maybe you want some realistic paper flowers? Moving on to that great first step is Animated Paper, which is simply nitinol memory wire bonded to paper via our favorite tool, duct tape.

Memory wire is first bent to its desired shape, and in order for it to hold that shape it needs to be heated to about 540 degrees Celsius, which is a easy task for a propane torch. Once it has its memory shape the wire can be bent into any shape desired, and when heated to about 70 degrees Celsius will return to its original set shape.

Taped down to a sheet of paper and letting some current from a battery run though it the wire quickly warms up and animates the paper, which could be exactly what one needs in a more artsy robot or electronic display. Join us after the break for a short video.

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