When you think about knitting, you might picture grandmas clicking big wooden needles or something wintery, like a snow-covered lodge. But knitting is everywhere, producing just about everything you put against your skin each day, from socks and t-shirts to hoodies and beanies. And thousands of years after it was first invented, new kinds of knitting are poised to fundamentally change how we think about these "basics," making our bodies more connected than ever to the computerised world we live in.
Today, you can buy a $US40 dress from Uniqlo that was produced by a knitting machine in one piece with no cutting or sewing - which means no seams and almost no wasted fabric. This "seamless" or "whole garment" knitting technique was first developed in Japan 20 years ago, but high costs have prevented it from hitting the mainstream until recently. The machines work something like 3D printers for clothes: yarn is loaded in, the machine is programmed, and out comes a full garment.
Bringing us performance wear like knit shoes, Adidas' Warp Knit leggings, and Nike's Pro Elite Knit shirts, this technique is arguably responsible for the rise of "athleisure" fashion. But paired with other innovations in the science of fibres, whole garment knitting opens the door to far more futuristic applications, like jackets that warm and cool you as needed or shirts that measure your heart rate.
The main difference between these potential products and the wearables we know (and are disappointed by) today, is that their technology can be seamlessly integrated into our clothes. Remove the battery, and such smart garments would be nearly indistinguishable from their un-enhanced ancestors.
A short history of knitting tech
Most of us probably wouldn't think of a plain, white t-shirt as a piece of technology, but this Walmart basic is the result of thousands of years of engineering, shaped by repeated waves of what we would now call "disruptive" technologies. While weaving likely came first, one of the oldest surviving items of fabric clothing is a pair of Egyptian socks made through nålbindning, an early form of knitting that used one instead of two needles. Imagine slipping your sweaty, callused feet into soft, knitted socks after a lifetime of wearing sandals or shapeless woven bags on your feet: knitting's first disruption.
During the industrial revolution, knitting and weaving machines became automated. The first automated loom, introduced in the early 1800s, was the forefather to the modern computer, utilising early binary code and inspiring the original Luddite revolts. When Silicon Valley was still farmland, innovations in the textile industry were shaping the globe, making some communities rich, enslaving others, and sparking wars and revolutions across the world.
In the near future, however, this largely invisible tech might soon be seen at the frontier of technology again as designers dream of new possibilities with electronically enabled textiles.
The future is squishy
When I asked Rebeccah Pailes-Friedman, the founder of Interwoven Design Studio, why knitting has been a focus for e-textile makers, her answer was simple: "The majority of what people own is already knitted," she said. "It's what people want to put on their body."
According to Despina Papadopoulos, the founder of Principled Design, knitting also has special attributes that are particularly suited towards advanced applications. Principled Design recently collaborated with Ralph Lauren for the battery-powered, self-heating 2018 US Winter Olympic Team Jackets, and Papadopoulos described modern knit technology as an expansion of control over form, especially with the integration of conductive yarns.
"You have more control in terms of dimensionality than you have with woven fabric," she said, referring to the "That dimensionality gives you both the ability to manipulate the structure of the fabric as well as to create pockets, to create layered structures that make incorporating electronics seamless, hidden, in a way that you cannot with other technologies."
The importance of seamlessness may seem small, but the failure of wearables like Google Glass demonstrate what happens when clunky tech products try to replace objects we're familiar with. Advanced knitting offers something past seamlessness approaching invisibility. Not only does it enable clothing makers to hide hard electronics, it even lets them create electrical components from the actual yarn — sensors that are an integral part of the garment and not tucked in or laminated on top.
For example, a knit machine programmer can create a small "patch" of conductive yarn, stack a non-conductive above it, and then another conductive patch on top of that to make a sandwich. As the two conductive sections get closer together, they make more and more contact through the non-conductive but porous sandwich "filling." This increased conductivity can be measured by a microchip to create a pressure sensor which, when built into a sock, could measure stride and footfall for runners or balance indicators in elderly patients who are prone to falling.
This knitting technique can also be used to create stretch, temperature, and humidity sensors and even begin analysing sweatiness which can convey the stress level of the user (not unlike in a lie detector machine) — applications currently in development for consumer products. Ultimately, 3D knit structures can become a plethora of sensors and actuators, antennae, and even allow for computer interaction through soft, knit protrusions that serve as buttons, or planar pads for gesture sensing.
One of the greatest challenges in the development of smart textiles has been making garments that are machine washable over time. The way most companies have tackled this problem is to include a removable "puck" (as it's called in the industry), which contains the device's battery and computer control. Lights, vibration motors, sensors, and the like remain in the garment and are either encased in plastic or laminate tapes for waterproofing, or are comprised of the conductive fibres themselves which are largely impervious to the washing processes.
Companies like Sensoria are already selling clothing with smart sensors laminated onto their products, but, crucially, knit production technology may soon enable all of this straight from the machine, without the secondary process of lamination, resulting in a cheaper, more streamlined product that's nearly indistinguishable from the knitwear we are familiar with today.
To spin a yarn
Advances in fibre technologies are definitely not limited to simple conductivity. I spoke with Yoel Fink, a professor of material sciences at MIT and the founder and CEO of Advanced Functional Fabrics of America (AFFOA). A federally funded textile research centre in Cambridge Massachusetts, AFFOA began with an initial input of 400 million and operates with a budget of 80 million per year.
"This is not a YouTube kind of operation," said Fink said via FaceTime while striding through his top-of-the-line textile research lab. He showed me various objects his researchers were working on, including a battery-scarf knit from yarn containing lithium-ion components so that the textile itself stores energy, a fabric that changes colours with minimal power needs (similar to the e-ink displays common in Amazon Kindles), and a baseball-cap that translates light from common ceiling mounted LED bulbs into audio. Finally, Fink held up some some normal looking all-black yoga pants that come alive with miniature, green LED lights.
The leggings are being developed through one of the techniques being pioneered at AFFOA for the fabrication of what Fink called “advanced yarns,” fibers containing conductors, insulators, and semi-conductors—the same necessary ingredients for a computer chip. To make the “yarn,” a cylinder of these three ingredients about 12 inches tall and six inches wide is heated and drawn out until it becomes incredibly thin.
“You make something big, you heat it up, and out comes miles of the same thing but really small,” Fink said. In this case, a hair-like black yarn which is then knit into yoga pants. To make these leggings without such yarns, you’d need to manually laminate silicon-mounted LEDs onto the surface of the pants one at a time, creating something uncomfortable, delicate, and very expensive. Fink’s version, on the other hand, is nearly indistinguishable from standard, athleisure-style leggings—except they can light up for a night-time jog.
When I asked Fink what it is about knit that is so desirable for making tech-enhanced clothing, he echoed Papadopoulos. “Knitting has this exquisite control that you get along with the [full] garment capability. There’s many more degrees of freedom in knitting in terms of being able to build structures.” Basically, you can have incredibly minute control over how a garment is shaped and where sensors and actuators are placed on the body. This also means that garments can be extremely customizable at a low cost. Already today, designers have used 3D scanning to create clothing specifically tailored to its wearers. In the near future, customers could be inputing biological specifics to tailor their chosen suite of sensors and actuators to integrate seamlessly with their unique biology.
But would you wear it?
Pailes-Friedman, Papdopolous, and Fink all agree that the costs will be coming down on technologically enhanced cloth, and this will fundamentally change the way in which we interact with technology — and hence, each other and our environments.
"We think textile and humanity are inseparable, so we think it could become a perfect computing platform, and that's part of the disruption we are trying to make," said Tony Chahine, CEO of Myant, one of the leading knit smart-textile groups. Fink agreed, also predicting that this will occur quite rapidly.
"In the years ahead, the basic properties, capabilities, and functions of fibres are going to increase in a way that is similar to what happened with Moore's Law in computer chips," he said. "There, the function doubled every 18 months. In the case of filaments I think it's going to double over a much shorter period of time, and you'll see this consistent increase in the capabilities of fibres and yarns and filaments." In the end, the smart apparel of the future could fundamentally change how we think about clothing, shifting it from a good to service. "You're no longer going to pay for the shirt, you're going to pay for what that shirt does for you," Fink said. "You pay for the service and you get the fabric."
"As humans, we value experiences and services a lot more than we value goods," Fink continued. "We relate to things that are unique…. we are looking for a little bit of something special. And when we get something that's special, we're prepared to pay for it. That's really whats happening in fabric, we're going to start to see some really special things happening."
A Myant sock with knit heated zones, pressure sensors and stretch sensors. (Battery not pictured.)Photo: Myant
We've come a long way from those Egyptian socks. Myant is developing socks that not only comfortably insulate and protect your feet, but also give them targeted compression, measure your posture and footfall, and even heat your feet automatically when they get cold. But the biggest question going forward is "What does the consumer want?" A wearable computing platform would inevitably create huge amounts of data from our bodies, something the public is understandably wary about.
"How does the customer feel about data?" said Pailes-Friedman. "What do they want from data? Right now I think it's pretty much a love/hate with data. For as much as we love having connected objects, every day we hear in the news about another hack, another abuse of data, another way we've been compromised and manipulated by our personalised data. That makes just as many people feel queasy as they also feel empowered. So there is a lot of questions about what can this data do that makes people feel good, what do people really want done?"
While a pair of smart socks that could be hacked to spy on you is a troubling idea, consumers will likely want connected clothing with far more basic functions. Pailes-Friedman paints a picture of a travel jacket that would flexibly respond to fluctuating weather patterns, warming us when it is cold and cooling us when it is hot. It's pretty obvious that we would want this jacket, but what other outputs acting upon collected data are of actual value to the everyday consumer? For now, the majority of data-focused innovators in this space are focusing on health and wellness, safety, athletic performance and recovery, and medical spaces. For the rest of us, we're looking at warming and cooling, lighting, and pattern changes. All the same stuff we look for in traditional fashion — with a techy twist.