Consumer Electronics

Smart Clothing: the Next Generation of Wearables

29 July 2016

Gazing into a crystal ball can be a risky business, but amidst the haze a few things seem clear about the future of wearables:

  • They remain hugely popular. Driven by fitness activity trackers (mostly bracelets to monitor walking, sleeping, heart rate, body temperature, blood pressure and calorie consumption), sales of wearables will chalk up a 39% increase this year, reaching almost 48 million units, according to the Consumer Technology Association’s mid-year forecast.
  • Encapsulated electronics woven into clothing—“smart clothing”—are primed to reach beyond fitness to a wide range of personal uses as the number of companies seeking to embed technology into the clothes we wear is multiplying exponentially. The analysis firm ABI Research predicts the smart clothing market will top 18 million clothing articles annually by 2021, representing a 48% compound annual growth rate (CAGR).

Smart textiles built from conductive polymers will enable built-in features, such as computing devices and multifunctional sensors, offering new possibilities for interacting with services, devices and environments. The goal in all cases will be twofold: (1) to create durable, practical and fashionable products that consumers want; and (2) to develop smart garments that can be treated in the same way and fit and feel the same as regular clothing.

Here are a few examples of current developments:

Project Jacquard involves the duo of Google and Levi’s, which have paired up to produce fabrics that can conduct electricity. At the core of the technology is a fabric that's specially woven with conductive thread, which allows it to act as an interactive touchpad (Fig. 1). Jacquard yarn structures combine thin, metallic alloys with natural and synthetic yarns like cotton, polyester or silk, making the yarn strong enough to be woven on any industrial loom.

Levi’s and Google teamed up to create the connected jacket (top). Captured touch and gesture data is wirelessly transmitted to mobile phones or other devices to control a wide range of functions (bottom). Levi’s and Google teamed up to create the connected jacket (top). Captured touch and gesture data is wirelessly transmitted to mobile phones or other devices to control a wide range of functions (bottom).

Levi's Jacquard-enabled “commuter trucker” jacket contains a swath of this fabric on the edge of one sleeve. Sensor grids can be woven throughout the textile, creating large, interactive surfaces. With the Levi's jacket a wearer can touch the sleeve of his or her jacket to control their phone using Bluetooth. It will work with Spotify, Google Maps, Strava and Google applications.

The miniaturized electronics in the jacket capture touch interactions, and various gestures can be inferred using machine-learning. The touchpad itself is powered by a small dongle that connects to the sleeve's cuff. Charged via USB, it is designed to look like the snaps and buttons on the rest of the jacket, though somewhat larger than the snaps typically found on a sleeve. To wash the jacket simply remove the tags, which are equipped with a light-emitting diode (LED) light that changes colors based on what the wearer is doing.

Printed inks and conductive yarns will be stitched into high-volume clothing later this year thanks to electronics manufacturer Flex (formerly Flextronics International) in partnership with MAS Holdings, a Sri Lanka-based technology apparel solutions provider.

Acting on the principle that bright lights can enhance the safety of a person when he or she is running, cycling or working in the dark, the new Firefly activewear clothing includes integrated LED lighting, embedding a series of 18 sewn-in green LED lights which flash in a pattern that looks like a moving person (Fig. 2). This avoids the challenges of current clothing-based safety systems—reflectors rely on external light sources, so a driver may not see a reflector on a jacket in time.

Firefly products include shirts and safety belts with integrated LED lighting designed to make running, bicycling or working on a construction site much safer. Firefly products include shirts and safety belts with integrated LED lighting designed to make running, bicycling or working on a construction site much safer.

Flex worked with MAS Holdings to make sure the motion of the flashing lights would look like a person running or riding a bike from a long distance away, as the lights show a runner’s moving arms or a bicyclist’s cycling legs. The battery charge on a shirt is expected to last about five hours between charges.

MAS and Flex previously worked on the Lumo Run product. In this smart clothing application, a small and discreet Lumo Run sensor attaches to the back of a pair of running shorts. Just clip it on and start running. Lumo Run is based on sports biomechanics research on distance running conducted at Loughborough University in the UK.

A novel transparent sensor material developed by Germany’s Fraunhofer is said to enable movement by allowing measuring sensors to be printed onto textiles. This new sensor technology soon will be incorporated into a prototype shirt called a MONI shirt, which will feature a number of functions but is foremost designed to monitor movement sequences.

As an initial step, Fraunhofer developed novel piezoelectric polymer sensor printing pastes said to be free from toxic solvents and created the necessary evaluation electronics. The next development steps will include field tests on several types of textiles and applications, followed by wear and washability tests.

A simple screen printing process is all it takes to apply the sensor pastes onto textile fabrics or plastic films. Manufacturing encompasses two steps: First the pattern is printed. Then the sensors are subjected to an electric field, making the piezoelectric polymers align to adopt the targeted pressure sensitivity. The screen printing process is said to be cost-efficient—a definite plus when it comes to industrial use and key to the mass production of printed sensors on textiles.

Thanks to its transparency and flexibility, the new sensor material offers the freedom to design in textile and garment color, and form. As the sensors are much thinner than a human hair, the wearer will hardly notice them embedded in a garment. There is yet another benefit: the sensors do not require any power source such as a battery. Instead they are expected to use harvested energy.

Noble Biomaterials’ Circuitex technology enables the integration of electronics into wearable garments and accessories in a format that is virtually invisible to the end user. Circuitex fabric conducts electricity, dissipates static and provides EMI shielding in applications where data transmission networks and electronics require protection from interference or interception.

When integrated into soft-surface wearable products, Circuitex can detect and monitor human physiological signals for fitness or healthcare applications. Sensor data can then be transmitted to external processing devices. Circuitex works by bonding a non-conductive polymer, such as nylon, with 99.99% pure silver. The pure silver covers 100% of the surface area around the fiber, which then creates a highly conductive and uniform product. The resulting materials can be processed in traditional textile manufacturing machinery. Because it involves the same manufacturing processes and machinery as working with traditional fabric, no special handling or considerations are required. Fabrics made with Circuitex can be terminated with common connectors and electrodes. Circuitex technology can be found in products such as the Ralph Lauren Polo Tech shirt and the Adidas miCoach.

When connected to an application-driven device, the Hexoskin Smart Shirt measures heart rate, breathing, steps, pace and calories. When connected to an application-driven device, the Hexoskin Smart Shirt measures heart rate, breathing, steps, pace and calories.

Montreal-based Hexoskin has developed a smart shirt for runners and other athletes that, when connected to an application-driven device, measures heart rate, breathing, steps, pace and calories (Fig. 3 above). Some of the features that come with the Hexoskin product are a battery with 14 hours of life; Bluetooth capability (Hexoskin supports the BLE profile); and compatibility with iPhone, iPad and Android devices. Hexoskin Smart connects natively to a wide range of GPS sports watches, allowing you to leave your phone at home. The Hexoskin Smart shirt is made of Nylon 6.6 fabric, which is valued as much for its feel as its performance traits.

Hexoskin is collaborating with Analog Devices and Microsoft to develop a unique, wearable Internet of Things (IoT) solution for athlete and team performance management. The solution allows coaches and team staff to monitor player information such as motion, heart rate and other useful health and performance metrics from sensor-equipped vests worn by players. This information, combined with player location and environmental data, is sent to a secure, cloud-based analytics platform via Microsoft’s Azure IoT technology.

Going forward the biggest challenge for the smart clothing segment is ruggedizing the technology that makes the clothing smart, including standing up to regular washing. At the moment, clothes drying is beyond the scope of smart textile technology because of the high temperatures and mechanical tumbling that entails. But don't rule it out entirely, given the progress being made and, as mentioned at the outset, the fact that predicting the future is an imperfect science.

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