New technology that harnesses electronic signals in smart fabrics could lead to advanced hazmat protective gear, according to research from a team at the US-based Dartmouth College.
Researchers suggest that by developing the electronic harnesses, wearers could be protected against toxic chemicals by not only detecting them, but also by capturing and filtering them. Published in the Journal of American Chemical Society, the research states that the technology could hugely benefit the military and emergency service personnel.
The chemistry team, consisting of Katherine Mirica and Merry Smith, describe the creation of the Self-Organised Framework on Textiles (SOFT) fabrics in what is noted as the first demonstration of simultaneous detection, capture, pre-concentration and filtration of gases in a wearable that uses conductive, porous materials integrated into soft textiles.
The research states that the SOFT devices have the potential for us in sensing applications ranging from gas detection in wearable systems in real-time, to electronically accessible absorbent layers in protective equipment such as gas masks.
Describing the development, Mirica says: “By adding this fabric to a protective suit, sensors can alert the user if a chemical is penetration the hazardous-material gear. This is not just passive protection, the textile can actively alarm a user if there is a tear or defect in the fabric, or if functional performance is diminished in any other way.”
Adding to the number of firsts seen in the research are flexible, textile-supported electronic sensors based on materials known as metal-organic frameworks (MOFs). In the report, the authors also describe a ‘simple’ approach for integrating these conductive, porous materials into both cotton and polyester fabrics to create the e-textiles.
As part of the study, the team demonstrated that the new smart textile was capable of detecting common toxic chemicals. Both nitric oxide, the vehicle exhaust pollutant, and hydrogen sulphide, the corrosive poison that reminds many of the scent of rotten eggs, were effectively identified by the SOFT system.
Mirica says: “Metal-organic frameworks are the future of designer materials, just like plastics were in the post-WWII era. By integrating the MOFs into our SOFT devices, we dramatically enhance the performance of smart fabrics that are essential to safety and security.”
The team involved in the research also described a one-step e-textile fabrication method based on MOFs – which likely constitutes the first use of direct self-assembly to deposit the conductive material on textiles.
Mirica describes the process as “similar to a building framework assembling itself,” as the cotton and polyester textiles coated with conductive crystals at fibre-level are produced by the direct self-assembly of molecules with organic molecular struts connected by metallic inkers from solution.
Varying applications
Wearable electronics have big potential in areas such as security, communication and healthcare, and developments such as this will continue to boost the promising and growing reputation of the industry.
For example, soldiers, emergency personnel, factory works and people in many other professions who risk exposure to toxic chemicals on a daily basis as part of their jobs could benefit from the new fabrics. The materials could also help medical patients who require monitoring of specific airborne chemicals which come from the surrounding environment, or even from their own bodies.
The researchers state that the SOFT devices featuring MOFs display reliable conductivity, as well as enhanced porosity, stability to washing, and flexibility. In addition, the fabrics are also stable in heat, have good shelf-lives and retain a full range of utility in humid conditions.
Although the technology requires further development before it can be used for real, the research team are hopeful that the fabrication method has the future potential to be extended into other systems, producing a range of new, multifunctional e-textiles with impressive qualities and an array of new applications in portable and wearable devices.
Source: www.wtin.com