A research team of The Hong Kong Polytechnic University (PolyU) has achieved a revolutionary breakthrough in smart materials, successfully developing soft magnetorheological textiles that can flexibly deform and modulate their mechanical properties under a human-safe magnetic field. Driven by electricity and programmable control, these new materials combine lightweight, flexible and breathable textile characteristics, making them widely applicable in smart wearables, soft robotics, virtual reality and metaverse haptic experiences.
Traditional magnetorheological materials have long faced two major drawbacks: heavy magnetic powders and the potential health risks posed by high-strength magnetic fields to the human body. Prof. TAO Xiaoming, Director of the PolyU Research Institute for Intelligent Wearable Systems, Vincent and Lily Woo Professor in Textiles Technology and Chair Professor of Textile Technology of the School of Fashion and Textiles, who led the research, elaborated, "The core objective of our research team is to overcome the application limits of traditional magnetorheological technology, extending it to fibre form, and enabling precise intelligent modulation while remaining compatible with textile properties such as softness and breathability."
The research team fabricated soft magnetic polymer composite fibres – just 57 micrometers in diameter – by uniformly dispersing magnetic powders in a plastic material (a low-density polyethylene matrix). These fibres not only achieve precise control under low-strength magnetic fields but also solve the problem of heavy magnetic powders. Furthermore, they can be spun into yarns and multi-layer fabrics to realise large-area, controllable deformation. This groundbreaking research was awarded HK$62.37 million under the Research Grants Council's 2024/25 Theme-based Research Scheme, and has been published in the international journal Nature, in the paper titled "Vector-Stimuli-Responsive Magnetorheological Fibrous Materials".
Unlike traditional smart materials that respond to scalar stimuli such as voltage, current or temperature, these in-house-developed magnetorheological textiles offer unique directionally controllable responses, enabling the development of the following three innovative fabric materials.
- Flexible Smart Gripper: With electric current controlling the fabric stiffness, the gripper can flexibly grasp soft, fragile or irregularly shaped items – such as worms, tofu, blueberries, mung bean cake, potato chips and fusilli – just like human fingers, significantly reducing the risk of damage or deformation during operation.
- Remote Emulation Haptic Finger Glove: The all-fabric materials can accurately replicate the surface textures and tactile hardness of different objects. Lightweight and comfortable to wear, they are suitable for diverse applications ranging from remote surgical training, stroke rehabilitation training and virtual fitting, addressing the common drawbacks of bulkiness and heaviness in similar haptic gloves available on the market.
- Active Ventilation and Thermal-Regulation Fabrics: Addressing the moisture and thermal management challenges in textile clothing, these fabrics can intelligently adjust air permeability by driving fibre structure deformation through electronically controlled magnetic fields, thereby significantly enhancing wearer thermal and moisture comfort.
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The Flexible Smart Gripper can flexibly grasp soft, fragile or irregularly shaped items with electric current controlling fabric stiffness. |
 The Remote Emulation Haptic Finger Glove can accurately replicate the surface textures and tactile hardness of different objects. |
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The Active Ventilation and Thermal-Regulation Fabrics can intelligently adjust air permeability by driving fibre structure deformation through electronically controlled magnetic fields. |
Prof. Tao explained the materials' potential, "The key breakthrough of this research lies in converting traditional rigid magnetic devices into flexible alternatives. This success can be extended to the development of hard magnetic fibre materials, laying a foundation for the next generation of soft robotics, electromagnetic devices and wearable technologies."
Regarding the prospects for industrialisation, Dr PU Junhong, Assistant Professor (Research) of the School of Fashion and Textiles, added, "From raw material selection to processing technology, we have taken industrialisation needs into consideration. We adopt commodity-grade, mass production-ready raw materials and mature processing techniques, paving the way for rapid translation in fields such as food production, medical rehabilitation and metaverse interaction."
