With the newly developed flexible nanotube fiber, one would not need to wear a smartwatch or chest strap for accurate heart rate monitoring, be it for a medical or fitness purpose.
According to a Phys.org report, that's the idea behind this smart clothing a Rice University laboratory recently developed, which used its conductive nanotube thread "to weave functionality" into regular or standard apparel.
The Brown School of Engineering lab of chemical and biomolecular engineer Matteo Pasquali reported in Nano Letters, the American Chemical Society journal, that it sewed nanofibers into athletic clothing to monitor the wearer's heart rate take his continual electrocardiogram or EKG.
Researchers of the study, Washable, Sewable, All-Carbon Electrodes and Signal Wires for Electronic Clothing, said the fibers are just as conductive as metal wires, although they are washable, comfortable while worn, and are far less likely to break while the body is moving.
Flexible Carbon Nanotube Fibers
Overall, the shirt the researchers enhanced was better at collecting data compared to a standard chest-strap monitor recording real-time measurements during experiments.
The carbon nanotube shirt, when matched with commercial medical electrode monitors, it provided slightly more accurate EKGs.
According to Lauren Taylor, a graduate student at Rice and lead author of the study, the shirt needs to be snug against the chest, as indicated in a similar Today Biz News report.
In future research, she added, they will focus on using denser patches of carbon nanotube threads, and thus, "there's more surface area to contact the skin."
The study authors also noted nanotube fibers are designed soft and flexible, not to mention, the clothing incorporating them is machine-washable.
Furthermore, the fibers can be sewn in a machine just like the regular thread. As described in the study, the zigzag stitching pattern enables the fabric to stretch minus breaking them.
Multiple Functions of Fibers
Taylor explained, the fibers they developed provided not just steady electric contact with the skin of the person wearing it, but it also served as electrodes to connect electronics such as Bluetooth transmitters to deliver data to a smartphone or connect to a "Holder monitor" that can be put in the pocket of the user.
It was in 2013 when the lab of Pasquali first introduced carbon nanotube fiber. Since then, fibers, each having tens of billions of nanotubes, have been examined for use as bridges to fix damaged hearts, as electrical interfaces with the brains, or can function for cochlear implants, as flexible antennas, among others.
As indicated in this report, the original nanotube filaments, roughly 22 microns wide, were very thin for a sewing machine to manage.
They worked with somebody selling small machines, designed to produce ropes for model ships, explained Taylor, who first tried to weave the thread through the hand, with limited success.
Her team is currently working with Dr. Mehdi Razavi and his colleagues at the Texas Heart Institute to find out how to maximize skin contact.
Fibers woven into fabric can be used as well to embed LEDs or antennas, the researchers said. Minor modifications to the geometry and associated electronics of the fiber could ultimately enable clothing to monitor vital signs, respiratory rate, or force exertion.
Information about the flexible carbon nanotube fibers is shown on Rice University's YouTube video below: