DIY

Nike HyperAdapt Teardown: The Future is Now (in pieces, on our workbench)

Growing up, we all dreamed of sporting a pair of Marty McFly’s AirMags. The idea of slipping on a fresh pair of self-lacing sneakers seemed, at the time, wildly far-fetched (like the notion of handheld computer tablets, self-driving cars, and hoverboards). Now, what appeared to be a distant dream, has become an exciting reality — thanks to the team at Nike. 

The Nike HyperAdapt is a first-of-its-kind product in an entirely new category. These self-lacing shoes combine intricate mechanisms, sophisticated electronics, and unique textiles. Mindtribe has been in the connected hardware space for 20 years, and it’s been exciting to watch the evolution of wearable, embeddable technology as it moves from smartphones, into wristwatches — and now into everyday wear. The HyperAdapts look and feel great, and it’s hard to overstate how cool it is to have the shoe self-lace around your foot as if by magic. It’ll certainly be interesting to see where Nike takes their concept next.

Our team had the opportunity to look inside a pair. By doing so, we were able to see the systems that drive the concept, and the possibility for further expansion and functionality — a peek back to the future.

Teardown – Peripherals

Before we start tearing into the shoes, let’s take a look at the lacing system. 

Two plastic channels run up from the motor compartment, exposing a technical fiber that Nike calls “Flywire,” which tightens the laces.

The “laces” that are visible look like polyethylene cable sheathing, in a custom pattern. The Flywire weaves through the “laces” and a number of reinforced loops in the shoe upper to form the lacing system. Much more on the lacing system later.

Pull out the insole, pull up the bootliner, and find the cool electronics inside! Looks like we’ve got some flex PCBs, board-to-board connectors, and we can see a battery and a motor down there.  

 

Buttons 

The buttons on the side of the shoe are a rigid flex PCB, covered with a flexible silicone or thermoplastic elastomer (TPE) overmold that has hard plastic inserts. Snap domes on the PCB provide the tactile button-press feel, which is a pretty standard button solution found for consumer electronics products.

A single elastic strap holds the button assembly in place, which means the buttons don’t always match up with the diamond markings on the outside of the shoe that are supposed to denote their location. Not a big deal as you can still easily find the buttons by feel.

Boot Liner & Heel Lights 

After dissecting the button assembly, we turn our knife to the boot liner. Removing that gives us a good view of the lacing system. The Flywire routes up from the bottom of the shoe, then through the cable sheathing across the top of the shoe. There are only two cables, which criss-cross to form the entire lacing system.

There’s a pressure sensor in the heel of the shoe that senses when the user puts the shoe on and tells the electronics to start the ‘lacing’ action.  This sensor is simply taped down; after carefully peeling it back we see that it’s a flex PCB with four individual sensors in it.

The heel lights are another rigid flex PCB, laminated into the plastic heel cup. To get them out, we had to resort to brute-force methods.  

After cutting out all of the inner padding and folding the heel outer down, a combination of a heat gun and careful knife work let us separate the inner and outer layers of the heel cup. 

With one more slit, we see the intact flex PCB.  

The heel lights, which flash when the HyperAdapts wake up or adjust lace tension, are a full rigid flex PCB, containing five RGB LEDs and a controller integrated circuit (IC).  You can see that Nike left as much copper as they could around the LEDs for heat sinking.

We did not notice light piping, shockproofing, or waterproofing around the board. There’s a thin layer of translucent black plastic between the LEDs and the world, which doesn’t do much to protect the board or diffuse the light. You can actually see the individual blue and green LEDs if you look closely at the cover photo, rather than the even, teal glow you might expect.  Most consumer products have a dedicated piece of plastic to diffuse the LEDs. Nike has omitted that here, maybe to save space or weight.

Motor and Battery Assembly

With all of its peripherals removed, the motor and battery assembly just pops out of the shoe with a screwdriver. 

The most interesting feature on the outside of the box is this large peripheral connector, which has several unpopulated pins, and even a 3-pin header coming off of it with nothing connected to the other end. 

This might suggest Nike is planning to introduce more peripherals for this system later. Those extra pins could connect to anything: a step-energy harvesting system to charge the battery; or an accelerometer for Nike+iPod-style activity tracking; maybe even a bluetooth module so your HyperAdapts can work with an app and adjust tension as soon as you’re getting near the track or court. 

Lacing 

We turn our attention to the only thing still holding the electronics in the shoe – the lacing itself. 

One interesting thing to note is that immediately after exiting the motor and battery assembly box, the Flywires each take two almost-90-degree turns.  People familiar with ropes and cables will tell you that these angles can put a lot of stress on the Flywires.

Nike must have a lot of faith in the strength and wear-resistance of their Flywire.  A little research reveals that Flywire is a high-strength fiber Nike uses in several of their product lines. It’s an embroidery-style thread made of Vectran®, a spun liquid crystal polymer made by the Kuraray company in Japan. Kuraray claims that Vectran fibers have a strength similar to Kevlar, and we can personally attest that they’re really, really strong.

They also pass through these cool tubes that are sewn into the sidewall of the shoe.

Lacing Pattern: Rather than try to explain the lacing pattern to you, we made this video instead!

Freedom!

Now that we have freed the smarts from the shoe, we can poke around them a little bit.

Like most modern electronics, this device is covered in small QR codes for part tracking in the factory.  For Nike, a company with hundreds of product lines and thousands of styles, this must be critical.

From the top, we get a rare chance to see into an assembly with clear polycarbonate packaging. We can see the battery, motor, gearbox, winding mechanism, and some kind of encoder at the top right.

From the bottom, we remove a piece of white tape and find an array of eight magnets which attaches the charger to the shoe.  We also see the big induction coil that handles wireless charging and the other side of our motor/gearbox/winding assembly.  

The side of this box holds the LED array to light up the side of the shoe.  Rather than a lightpipe, Nike has chosen to use a densely-packed grid of top-firing and side-mount LEDs to give a uniform glow.  You can even see the little series resistors for all of those RGB LEDs.  

Teardown – Gearbox

After quite a bit of prying, we finally separate the two halves of the box. We can see some surprisingly heavy-duty hardware in here.

This metal, multiple interlocking gearbox is heftier than the standard brass or plastic gearbox you see on most consumer products. And judging by the gear ratio, this thing is built to generate a lot of torque.

With the cover off, we can see there’s a threaded part at the end of the winding spindle that passes through an optical gate, letting the shoe know if it’s tightened (or loosened) too far. 

This unit outputs an impressive amount of pull force for its size, easily in the neighborhood of 30+ lb. before stalling out. You don’t often see a box that fits in the palm of your hand and can lift three gallon jugs of milk, with power to spare. The gearbox helps by stepping down the RPM while increasing the torque, but how fast must the motor be spinning? We recorded an audio clip of the motor running and ran it through Audacity’s Fast Fourier Transform (FFT). 

We think the 600Hz is the motor with the other spikes being harmonics or brush noise. This would correspond to approximately 36,000rpm. 

That’s very impressive! 

Though not waterproof, the polycarbonate case is built to take a beating.  There are screws to hold it together around the gearbox and motor, ribs everywhere, and it is made out of plastic that’s known for its resistance to impact.  

Flip the battery up, and we find out it’s a 630mAh LiPo, about three times larger than the Apple Watch battery. 

The Electronics Board

The main board packs an impressive amount of electronics. Its heart is an ARM Cortex M4 main processor that controls the entire mechanism as well as various other peripherals. The smarts for the wireless charging are also found in here. The HyperAdapts use a protocol called Qi, which is becoming more commonplace in smartphones like the Nexus 5 and 6 and Galaxy S6 and S7. A driver chip for the motor is also used to detect the increase in current draw when the laces have been done up too! Pretty smart!

A few details that the more tech-savvy hardware enthusiasts may be interested in:

  • The wireless power receiver is a Qi-compatible wireless charging IC, a standard that is being seen more and more in consumer devices.
  • The motor driver is a very elegant solution for driving DC motors with all sorts of special features and protection, especially useful to make sure your shoes don’t catch fire!
  • The main processor is from Atmel (now Microchip), which packs what seems to be an overkill ARM Cortex M4 processor. However, it is specified for very low power operation. Maybe this hints to future features being added in with this set of hardware?

LED board

There is a separate little board, connected at right-angle to the main one, which is responsible for the cool blue glow coming from the side of the shoes. This board houses a huge array of tiny little lights. 

Interestingly, Nike chose to use an array of 32 top-emitting and 14 side-emitting RGB LEDs here.  At first, this seems excessive to light up such a small area, but all those LEDs provide a uniform brightness across the side of the shoe, where one or two large LEDs would have created bright spots. 

Also the board that they are mounted on has some mysterious burn marks on it, where it looks like it might have been depanelized with a laser. (Depanelization is the process of separating one large board into lots of smaller ones. This is usually done at the end of the manufacturing process, so you don’t have to handle a bunch of small boards individually).

Heel LED flex

This flexible circuit has some more electronics wizardry in it by being able to drive 15 tiny lights from only 4 wires. They use a clever controller from Texas Instruments to achieve this. 

Some very careful design and manufacturing must have been used here to ensure the components were not subject to unnecessary stress which could easily break electronics and their housing while being made.

Teardown – Charger

After some abortive cutting and prying, we realize two things.  First, that the two halves of this enclosure are stuck together remarkably well (either with an ultrasonic weld or glue) and are unwilling to separate without a fight. Second, that the shape makes it uniquely suited to be cracked open like a nut.  

We reach for our trusty vise, and after some tight squeezing and a loud “pop,” we’re in. 

Inside, we find a board (with beautifully labeled test points) and a small breakout that holds the LEDs around the charge cable. 

The main chip looks to be a low-cost, Chinese pre-built, Qi compatible, charger solution.

Removing a few screws and flipping up the board shows us the inductive charging coil and the magnets below, matching those we saw in the shoe earlier. 

Closing Notes

First-of-their-kind products present tough technical challenges. Building a tiny, rugged, high-torque system that fits into a wearable and provides a seamless user experience is no easy task, especially for a company that primarily focuses on softgoods. 

We were impressed by the layering and reinforcement schemes in the fabric as well as the textiles they used — it turns out that Nike knows a thing or two about making shoes.

Are there some rough edges? Sure.  But every first-gen product has room for improvement, and we commend Nike for leading the charge to a self-lacing future. This was a really interesting piece of hardware to tear down and it seems like there’s some possibility for expansion — like energy harvesting, bluetooth connectivity, or activity-specific lacing profiles, for example — built into the system. Meaning a self-lacing future might be closer than you think.