Inventors from the University of Waterloo in Canada detailed the properties of a new smart fabric in an article for the journal Nano-Micro Small. The team calls it the world’s first material to respond to heat and electricity at the same time. When exposed to those stimuli, the fabric changes color and shape, then returns to its original state after the stimuli are removed.
To make the fabric, researchers used a device similar to a traditional loom. They wove thin, intertwined threads of recycled plastic and stainless steel, the team reported.
Compared with earlier versions, the new fabric activates at a much lower electrical voltage, making it cheaper and more energy efficient. Because of the low voltage, the material could be used in portable devices such as biomedical instruments and sensors. The researchers also say the smart fabric could enable anti-counterfeiting technology, orthopedic devices, and biomimetic applications. Eventually, it could be used for smart clothing and everyday consumer goods.
Temperature sensitivity is one of the most common triggers studied for shape- and color-changing smart materials because it’s convenient and simple. But the team says achieving precise stimulation is usually very complex.
To give the fabric color-changing ability, the researchers wove extra threads that contain thermochromic microcapsules (TMC) alongside the conductive stainless steel threads. When heated, the outer shell of the TMCs becomes translucent; after cooling it becomes opaque again and the original color returns.
To demonstrate the potential of the invention, the team made a dragonfly-shaped model from the smart fabric and subjected it to heat and electrical stimuli.
“Thanks to its ability to respond to environmental stimuli such as temperature, our new material can be used to monitor ecosystems without harming them,” said Milad Kamkar, a professor of chemical engineering and the paper’s lead author.
