Breakthrough Material Enhances PPE Flexibility and Protection

A textile engineer at Heriot-Watt University has developed an innovative material poised to significantly improve the comfort and protective capabilities of personal protective equipment (PPE). Traditional protective gear often relies on bulky foam for impact absorption, a design that can restrict movement. This new development offers a promising alternative. Dr. Saadullah Channa, based at the School of Textiles and Design (SOTD) in Galashiels, has utilised 3D printing to create a soft, flexible resin material. This material is structured in a re-entrant honeycomb pattern, a departure from conventional hexagonal designs. Unlike typical materials that narrow when stretched, this re-entrant structure possesses auxetic properties, meaning it expands when pulled and contracts when impacted. This unique characteristic simultaneously boosts both flexibility and resistance. Initial assessments of this 3D-printed auxetic material have yielded encouraging results. A mere 5mm layer of the new material demonstrated approximately three times greater impact protection compared to an equivalent thickness of standard foam. Crucially, it also flexes in all directions, enhancing comfort and mobility without compromising safety. While the primary focus of Dr. Channa's research was to improve the ergonomics of sportswear, the material also holds substantial potential for applications in other fields, including healthcare. His work, which formed part of his Ph.D. studies, aimed to reduce foam thickness while simultaneously boosting impact resistance. He noted that these 3D-printed re-entrant honeycomb structures show considerable promise for PPE, potentially safeguarding areas like knees, hips, elbows, and shoulders by ensuring comfort, facilitating natural body movements, and offering an impact-resistant solution. Conventional protective foams often incorporate polyurethane, where tiny hardened bubbles form a robust, impact-absorbing structure. However, these foams can be cumbersome and are frequently combined with harder elements to improve durability. Dr. Channa's research found that by arranging a similar polyurethane-based flexible resin into a re-entrant honeycomb pattern, a higher level of protection could be achieved with less thickness, significantly improving mobility. A series of experiments conducted at the Galashiels campus involved using sensors to measure the forces transmitted through the material upon impact. These tests confirmed exceptional energy absorption, validating the effectiveness of the auxetic structure. Dr. Channa expressed considerable excitement about the results, suggesting that this approach could revolutionise the design of protective wear, making it more comfortable without sacrificing safety. This study is believed to be among the first to investigate both the mobility and impact resistance of an auxetic material, paving the way for more advanced applications in protective clothing. Dr. Channa plans to collaborate with industry partners, including prominent sports brands, to bring his material to market. Dr. Danmei Sun, Associate Professor in Textile Materials and Technology at the School of Textiles and Design and academic supervisor of the research, commented on the transformative potential of Dr. Channa's Ph.D. work. She highlighted its capacity to offer an alternative to traditional protective foams by enhancing both flexibility and impact resistance, thus balancing safety with mobility. This innovation, by reducing material thickness while improving energy absorption, could lead to more comfortable protective gear across various sectors, such as healthcare, sports, and emergency response.