Smart textiles or smart fabrics, borrow their name from the inclusion of features or technologies that no longer make a coat just a coat – but one capable of, for example, harvesting your energy to create a power source. Integrating electronics into textiles opens up a world of possibilities at the same time it raises questions about power consumption, battery life and sustainability.
What are smart fabrics?
Smart fabrics are typically designed to sense, react and communicate, which requires power. IoT-enabled smart fabrics tend to refer to the incorporation of flexible sensors that are lightweight, stretchable and durable enough to be embedded in textiles and with the capabilities to measure temperature, humidity, pressure and movement. Strain sensors detect body movements; while electrochemical sensors monitor biochemical parameters such as glucose or lactate levels in sweat.
A major challenge is embedding IoT technologies and electronic components into fabrics and powering them efficiently. To meet the sometimes hefty demands on power, researchers are looking at a range of solutions including energy harvesting, rechargeable batteries and ultra-low-power semiconductors.
Arguably one of the most exciting avenues for powering smart fabrics is energy-harvesting technologies which collect energy from the wearer’s surroundings. This includes piezoelectric fibres, which generate electrical energy when subject to movement, such as walking or stretching; thermoelectric materials which convert temperature differences into electrical energy; and solar-powered textiles which use lightweight solar cells to potentially create self-sustaining textiles.
Rechargeable microbatteries are another promising solution, as developments in lithium-ion microbatteries and solid-state batteries offer a longer cycle life. These batteries can be embedded directly into garments to provide a longer power supply without increasing the weight of the wearable, per se.
Ultra-low-power semiconductors are designed to perform data processing and wireless communication with minimal power consumption. The development of sub-threshold voltage circuits and energy-efficient processors mean smart fabrics may be able to operate for longer on a single charge.
Real-world examples of smart fabrics
At the University of Waterloo, in Canada, researchers have designed a smart fabric with the potential to harvest energy to create heat, or monitor biometrics like your heart rate and temperature. It also has the capability to detect temperature changes ad sensors monitoring pressure, chemical composition and other parameters
The fabric converts body heat and solar energy into electricity which creates the possibility for the fabric to operate without an external power source. At the time of the announcement, Yuning Li, a professor in the Department of Chemical Engineering who led the research team said: “We have developed a fabric material with multifunctional sensing capabilities and self-powering potential. This innovation brings us closer to practical applications for smart fabrics.”
The idea is that the fabric will replace existing wearables which need to be charged to continue to operate. “AI technology is evolving rapidly, offering sophisticated signal analysis for health monitoring, food and pharmaceutical storage, environmental monitoring, and more,” said Li. “However, this progress relies on extensive data collection, which conventional sensors, often bulky, heavy, and costly, cannot meet.
“Printed sensors, including those embedded in smart fabrics, are ideal for continuous data collection and monitoring. This new smart fabric is a step forward in making these applications practical.”
In an illustration of how researchers have approached smart fabrics differently, at the Massachusetts Institute of Technology (MIT) researchers within the Media Lab have applied thermoforming – incorporating a type of plastic yarn and using heat to melt it – to improve the precision of pressure sensors woven into knit textiles, to fit to the body and sense the user’s postures and motions.
The researchers created a smart shoe and mat, and subsequently built a hardware and software system to measure data from these sensors in real time, predicting motions and yoga poses.
The hope for this kind of smart fabric is for the benefits it will bring in use cases like healthcare and rehabilitation, for instance smart shoes that track the gait of someone rehabilitating after an injury.
In the announcement, Joseph A. Paradiso, Alexander W. Dreyfoos Professor and Director of the Responsive Environments Group within the Media Lab, said: “Some of the early pioneering work on smart fabrics happened at the Media Lab in the late ’90s. The materials, embeddable electronics, and fabrication machines have advanced enormously since then. It’s a great time to see our research returning to this area, for example through projects like Irmandy’s — they point at an exciting future where sensing and functions diffuse more fluidly into materials and open up enormous possibilities.”
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