Researchers at the University of Waterloo have developed a new smart material with a dual-response feature, that is, shape-memory and color-changing. The unique design paves the way for a wide variety of potential applications, including clothing that warms up while you walk from the car to the office in winter and vehicle bumpers that return to their original shape after a collision.
The new smart material is activated by both heat and electricity, making it the first ever to respond to two different stimuli. Image credit: Xu et al., doi: 10.1002/smll.202207900.
Stimuli-responsive materials, as a novel category of smart materials, are able to change their certain properties in response to an external stimulus such as heat, light, pH, moisture, and electric, as well as magnetic fields.
To date, most researchers have mainly focused on single-responsive materials, that is, shape-memory or color-changing.
However, it is critical to design and engineer multi-SRMs to take SRMs steps forward in today’s technologically advanced world.
Multi-stimuli-responsiveness can introduce more new functions to smart systems such as camouflage, bionics, actuators, and sensors.
“As a wearable material alone, it has almost infinite potential in AI, robotics and virtual reality games and experiences,” said University of Waterloo’s Professor Milad Kamkar, co-senior author of the study.
“Imagine feeling warmth or a physical trigger eliciting a more in-depth adventure in the virtual world.”
The novel fabric design is a product of the happy union of soft and hard materials, featuring a combination of highly engineered polymer composites and stainless steel in a woven structure.
Professor Kamkar and colleagues created a device similar to a traditional loom to weave the smart fabric.
The resulting process is extremely versatile, enabling design freedom and macro-scale control of the fabric’s properties.
The fabric can also be activated by a lower voltage of electricity than previous systems, making it more energy-efficient and cost-effective.
In addition, lower voltage allows integration into smaller, more portable devices, making it suitable for use in biomedical devices and environment sensors.
“The idea of these intelligent materials was first bred and born from biomimicry science,” Professor Kamkar said.
“Through the ability to sense and react to environmental stimuli such as temperature, this is proof of concept that our new material can interact with the environment to monitor ecosystems without damaging them.”
The next step for the authors is to improve the fabric’s shape-memory performance for applications in the field of robotics.
“Our aim is to construct a robot that can effectively carry and transfer weight to complete tasks.”
The work was published in the journal Small.
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Runxin Xu et al. Multi-Stimuli Dually-Responsive Intelligent Woven Structures with Local Programmability for Biomimetic Applications. Small, published online February 19, 2023; doi: 10.1002/smll.202207900
