Specialized printing, fabrication could take place in e-clothing

Scientists at Case Western Reserve University have developed an inexpensive way to turn a simple shirt into an electronic smart shirt – capable of monitoring and adjusting body temperature or even heat to the wearer’s shoulder or back. allows installation.

All from a design printed on shirt fabric or any other piece of clothing.

The key to their innovation: a highly conductive ink and simple screen-printing process. The new method results in a waterproof, breathable and highly flexible design that can act as a heating element when powered by a coin-sized battery.

According to market analysts, the wearable technology market like Fitbit, Apple Watch and Bluetooth headset is growing. But a growing segment includes electronic technology embedded in clothing, implanted in a user’s body, or even tattooed on the skin.

The team of researchers led by Case Western Reserve believes its method expands into the wearable tech market for its simplicity, durability, comfort and eventually the price of someday.

They say that their process, successful in laboratory testing, may someday be implemented for mass production. The research team, which included collaborators in Wuhan, China, published their findings in the journal tiny,

Changyong (Chase) Cao, assistant professor of mechanical and aerospace engineering, said, “We believe this is actually a better approach than other efforts to build wearable technology because not only is good performance initially, but is sustainable long-term.” ” Case School of Engineering, who led the research.

Kao is also director of the Laboratory for Soft Machines and Electronics at Case Western Reserve. Most of the available designs for incorporating electronics into clothing are those with a polymer or elastomer surface, he said. These types of surfaces are often uncomfortable and not breathable.

Difference: conductive and durable ink

Other researchers have tried two other methods of integrating electronic fibers into fabric. Cao said some have tried spinning them into materials or depositing conductive materials on the surface of fabrics. The latter, such as spray-coating and dip-coating, is more common because it is faster and less expensive, he said.

“Our new method improves on those by using a low-cost screen-print method to achieve higher resolution levels,” he said. “This enables us to print the ink in more aesthetic patterns, or in intricate designs. Printed e-textiles are very stretchable and can work well even after multiple washes.”

The key, the researchers said, was the use of silver fractal dendrites—microscopic, branch-like filaments of silver. Filaments conduct electricity well – even if manipulated or deformed during use.

The team added microscopic solid metals to water-based inks. They bind the metals to the ink molecules with a clear and highly elastic adhesive.

The researchers then covered the ink with a thin layer of an invisible waterproofing agent that prevents the electrodes from cracking. Then he printed it on a cloth.

The ink then acts as a conductor of small amounts of electricity. TI can detect body movements and manage or control individual temperature.

The researchers used small coin batteries or button cells found in thermometers, car fobs or wristwatches to power an ink-based heating unit.