Equipment- and training-free textile detectors could be used in public health, workplace safety, military and rescue applications
Tufts University engineers have developed a novel fabrication method to create dyed threads that change color when they detect a variety of gases. 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.
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.
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 chemical and materials production. A three-step process "traps" the dye in the thread.
The thread is first dipped in the dye, then treated with acetic acid, which makes the surface coarser and swells the fiber, possibly allowing more binding interactions between the dye and tread. Finally, the thread is treated with polydimethylsiloxane (PDMS), which creates a flexible, physical seal around the thread and dye, which also repels water and prevents dye from leaching during washing. Importantly, the PDMS is also gas permeable, allowing the analytes to reach the optical dyes.
"The dyes we used work in different ways, so we can detect gases with different chemistries," said Sameer Sonkusale, professor of electrical and computer engineering at Tufts University's School of Engineering who heads the Nano Lab at Tufts and is corresponding author of the study. Sonkusale's team used simple dyes that detect gases with acid or base properties. "But since we are using a method that effectively traps the dye to the thread, rather than relying so much on binding chemistry, we have more flexibility to use dyes with a wide range of functional chemistries to detect different types of gases," he said.
The tested dyes changed color in a way that is dependent and proportional to the concentration of the gas as measured using spectroscopic methods. In between the precision of a spectrometer and the human eye is the possibility of using smart phones to read out and quantify the color changes or interpret color signatures using multiple threads and dyes. "That would allow us to scale up the detection to measure many analytes at once, or to distinguish analytes with unique colorimetric signatures," said Sonkusale.
The threads even worked under water, detecting the existence of dissolved ammonia. "While the PDMS sealant is hydrophobic and keeps water off the thread, the dissolved gases can still reach the dye to be quantified." said Rachel Owyeung, lead author and graduate student in the Tufts Department of Chemical and Biological Engineering. "As dissolved gas sensors, we imagine smart fabrics detecting carbon dioxide or other volatile organic compounds during oil and gas exploration as one possible application."
Since repeated washing or use underwater does not dilute the dye, the threads can be relied upon for consistent quantifiable detection many times over, the researchers said.
This work was supported by a grant from the National Science Foundation Institutional Graduate and Research Traineeship (DGE-1144591) for R.O.
Also contributing to this study is Matthew Panzer, associate professor of chemical and biological engineering at Tufts.
Owyeung, R.E., Panzer, M.J., Sonkusale, S.R "Colorimetric Gas Sensing Washable Threads for Smart Textiles." Scientific Reports, (4 April 2019). DOI: 10.1038/s41598-019-42054-8
About Tufts University
Tufts University, located on campuses in Boston, Medford/Somerville and Grafton, Massachusetts, and in Talloires, France, is recognized among the premier research universities in the United States. Tufts enjoys a global reputation for academic excellence and for the preparation of students as leaders in a wide range of professions. A growing number of innovative teaching and research initiatives span all Tufts campuses, and collaboration among the faculty and students in the undergraduate, graduate and professional programs across the university's schools is widely encouraged.
Mike Silver | EurekAlert!
If Machines Could Smell ...
19.07.2019 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA
Algae-killing viruses spur nutrient recycling in oceans
18.07.2019 | Rutgers University
Adjusting the thermal conductivity of materials is one of the challenges nanoscience is currently facing. Together with colleagues from the Netherlands and Spain, researchers from the University of Basel have shown that the atomic vibrations that determine heat generation in nanowires can be controlled through the arrangement of atoms alone. The scientists will publish the results shortly in the journal Nano Letters.
In the electronics and computer industry, components are becoming ever smaller and more powerful. However, there are problems with the heat generation. It is...
Scientists have visualised the electronic structure in a microelectronic device for the first time, opening up opportunities for finely-tuned high performance electronic devices.
Physicists from the University of Warwick and the University of Washington have developed a technique to measure the energy and momentum of electrons in...
Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.
Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...
For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.
Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...
An international research group led by scientists from the University of Bayreuth has produced a previously unknown material: Rhenium nitride pernitride. Thanks to combining properties that were previously considered incompatible, it looks set to become highly attractive for technological applications. Indeed, it is a super-hard metallic conductor that can withstand extremely high pressures like a diamond. A process now developed in Bayreuth opens up the possibility of producing rhenium nitride pernitride and other technologically interesting materials in sufficiently large quantity for their properties characterisation. The new findings are presented in "Nature Communications".
The possibility of finding a compound that was metallically conductive, super-hard, and ultra-incompressible was long considered unlikely in science. It was...
24.06.2019 | Event News
29.04.2019 | Event News
17.04.2019 | Event News
19.07.2019 | Physics and Astronomy
19.07.2019 | Physics and Astronomy
19.07.2019 | Earth Sciences