Written by Catherine Bolgar
Cool under fire: Past clothing innovations, such as Kevlar, have greatly enhanced personal safety, for example, by improving bulletproof vests. But being impermeable, such vests also keep out air and trap in the wearer’s sweat. It is a problem that researchers at the Swiss Federal Laboratories for Materials Science and Technology (EMPA) have tried to solve by developing a smart protective vest with an integrated cooling system using “Coolpad” technology originally designed for medical uses.
The Coolpad consists of two breathable membranes and a thin hydrophilic textile from which the added water is evaporated for cooling. An active cooling mechanism consists of a Coolpad and a ventilation system based on a spacer fabric (a three dimensional knitted fabric) to guide the air. A tiny fan, similar to that in a computer, pumps air through the spacer fabric, which in turn guides the air through the inside of the vest, increasing evaporation and cooling the wearer, Martin Camenzind, an EMPA electronic engineer, explains. A small water reservoir creates a mist in the fabric channels and, along with the perspiration, helps cool the wearer.
The drop in temperature varies according to how the Coolpad vest is worn. Sometimes a police officer will want to display his or her bulletproof vest, other times to hide it. When worn close to the skin, over a T-shirt, it can reduce body temperature by four to six degrees Celsius, says Mr. Camenzind. “You would feel even smaller temperature changes than that,” he adds. Furthermore, the active cooling system vest weighs about one kilogram, compared with the nearly 20 kilograms of equipment—including radio, gun, flashlight and more—that police officers regularly carry.
Hot fashion: At the other end of the thermometer, nanowire clothing could keep us all warm. Stanford University researchers have developed metallic nanowire-coated fabrics that reflect body heat back to the wearer, augmented by Joule heating in which an electric current releases heat. The clothing is also breathable, so the wearer stays comfortable. One benefit of the technology lies in not having to heat a whole house for its inhabitants to stay warm.
Walk like a robot: In another remarkable development, a Bristol University research team is developing soft-robotic clothing, such as smart trousers that support wearers as they walk or climb stairs, helping to prevent falls. Wearable robotics, especially for the elderly, might be more efficient than bulky walking aids or stair lifts, and more comfortable than braces that can restrict blood circulation.
Healthy fabrics: Other smart fabrics, being developed at the University of Laval in Quebec, can monitor and wirelessly transmit a wearer’s biomedical information. Such fabrics can provide a minimally invasive way to monitor chronic diseases, glucose levels, heart rhythm, brain activity, movement or location.
Clothes hide the man: In the distant future, scientists may be able to develop an “invisibility cloak,” using metamaterials—materials with properties not found in nature. Metamaterials could be used for better imaging, for visual prosthetics such as contact lenses, or for sensors. Metamaterials might also be used to create fabric with an interesting, colorful pattern that can change an object’s image, including its color, says Andrea Di Falco, lecturer in nano-photonics at the University of St. Andrews in Scotland. Researchers there are developing Metaflex, a flexible metamaterial with electromagnetic properties.
Metamaterials often consist of metal particles smaller than light waves. To make something invisible, a metamaterial must keep light from interacting with the material itself, Dr. Di Falco explains. “If you hide the object with a cloak but you see the cloak, you haven’t done the job. You have to hide the object and hide the cloak itself.”
Researchers are therefore experimenting with ways to bend or alter light in order to hide objects. But each object needs its own unique cloak, making it feasible on a small scale but impractical for bigger objects such as people, says Dr. Di Falco. “Cloaking today is possible provided you accept some limitations,” he says. “Will we ever be able to have a Harry Potter cloak? It’s possible, but it’s very, very far off.”
Catherine Bolgar is a former managing editor of The Wall Street Journal Europe.
For more from Catherine Bolgar, contributors from the Economist Intelligence Unit along with industry experts, join the Future Realities discussion.
Images courtesy of iStock