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.
The Latest on: Sensing threads
via Google News
The Latest on: Sensing threads
- Elon Musk says Neuralink plans 2020 human test of brain-computer interfaceon July 17, 2019 at 11:25 am
The startup uses sewing machine-like technology this year to drill small holes into brains and insert super-slender electrodes called threads, steering clear of ... and fitted it with a USB-C port so ... […]
- Musk's Neuralink will implant 'threads' to connect humans with computerson July 17, 2019 at 7:16 am
Several minute threads to be implanted into human brain ... Once the hole is plugged with a sensor, the system will start collecting data. ... […]
- Brain-on-a-chip: Elon Musk seeks human trials in 2020on July 17, 2019 at 5:07 am
The technology has a module that sits outside the head and wirelessly receives information from "threads" embedded in the brain. Controlled by an iPhone app, the chip called "N1 sensor" with just ... […]
- Elon Musk claims robot surgeon will sew electrodes into human brains in 2020on July 16, 2019 at 11:57 pm
The threads then record the information being transmitted onto a tiny sensor called the N1. Musk and Neuralink president Max Hodak told the audience that they aim to have the technology in an ... […]
- Elon Musk's Neuralink Says It's Created Brain-Reading 'Threads,' Surgical Robot That Inserts Themon July 16, 2019 at 11:50 pm
Those threads are designed to be both sturdy enough ... his company is currently developing much less invasive external sensor-based methods, adding “There is no way I’m thinking about ... […]
- Elon Musk unveils Neuralink’s plans for brain-reading ‘threads’ and a robot to insert themon July 16, 2019 at 9:24 pm
These threads also create the possibility of transferring a higher ... That wireless goal will be embodied in a product that Neuralink calls the “N1 sensor,” designed to be embedded inside a human ... […]
- Charge-Storing Threads Turn Fabric into Supercapacitoron May 12, 2019 at 5:00 pm
Using textiles and fabrics for harvesting power, storing energy, and bio-sensing makes sense—after all, everyone wears a shirt. A team at the University of Massachusetts has developed a way to combine ... […]
- Force-sensing gloves could control an iPhone by detecting gestures and how objects are grippedon April 18, 2019 at 5:03 am
The conductive strands are intertwined with normal threads, effectively making them invisible to the user, and without an obvious connecting wire between parts. The conductive strands are put into ... […]
- New gas-detecting threads can be sewn into clotheson April 7, 2019 at 5:00 pm
"One benefit of our entrapment method is that it can be used on different dye types, which is helpful for creating the sensor diversity needed for this distinguishing power." Researchers hope to ... […]
- Gas sensing threads can be woven into clothingon April 4, 2019 at 5:43 am
(Nanowerk News) 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 ... […]
via Bing News