These color-changing threads of fabric could become a brilliant new form of protection for workers and employees who work in close proximity to dangerous gases.

Engineers from Tufts University have developed a novel fabrication method to create dyed threads that change color when they detect a variety of harmful gases. Woven into clothing, smart, gas-detecting threads could provide a reusable, washable, and affordable safety asset in medical, workplace, military, and rescue environments, they say.

The study, published today in the journal Scientific Reports, describes the fabrication method and its ability to extend to a wide range of dyes and detection of complex gas mixtures. The researchers demonstrated that the threads can be read visually, or even more precisely by use of a smartphone camera, to detect changes of color due to analytes as low as 50 parts per million.

While not replacing the precision of electronic devices commonly used to detect volatile gases, incorporation of gas detection into textiles enables an equipment-free readout, without the need for specialized training, the researchers say. Such an approach could make the technology accessible to a general workforce, or to low-resource communities that can benefit from the information the textiles provide.

The study used a manganese-based dye, MnTPP, methyl red, and bromothymol blue to prove the concept. MnTPP and bromothymol blue can detect ammonia while methyl red can detect hydrogen chloride – gases commonly released from cleaning supplies, fertilizer, and from chemical and material production.