According to foreign media reports, Rice University researchers recently demonstrated a clothing with carbon nanotubes that can continuously monitor the wearer's heart. There's no need to wear an uncomfortable smartwatch or chest strap to monitor your heart if your comfortable clothing does a better job. That's the idea behind "smart clothing" developed by a Rice University lab that uses its conductive nanowires to weave functionality into regular clothing.
Matteo Pasquali, a chemical and biomolecular engineer at the school's Brown School of Engineering, reports in Nano Letters, a journal of the American Chemical Society, that it sewn nanotube fibers into sportswear to monitor heart rate and perform continuous electrocardiographic monitoring of the wearer. .
Segons els investigadors, les fibres són tan conductores com els cables metàl·lics, però són rentables, còmodes i molt menys propensos a trencar-se quan el cos està en moviment. En general, les seves peces millorades eren millors a l'hora de recollir dades que els monitors{0}}de corretges de pit estàndard que van prendre mesures de camp en els experiments. Quan es combinen amb monitors d'elèctrodes mèdics comercials, les peces de nanotub de carboni van tenir un rendiment lleugerament millor als ECG.
"The garment had to fit snugly against the chest," said Rice graduate student Lauren Taylor, lead author of the study. "In future research, we will focus on using denser blocks of carbon nanowires so that there is more surface area to contact the skin."
Els investigadors assenyalen que les fibres del nanotub són suaus i elàstiques, i la roba que les incorpori es pot rentar a màquina. Aquestes fibres es poden cosir a màquina a la tela com un fil estàndard. El patró de costura en ziga-zaga permet que els teixits s'estirin sense trencar-los.
The fibers not only provide a stable electrical contact with the wearer's skin, Taylor said, but also act as electrodes to connect electronic devices such as Bluetooth transmitters, relay data to smartphones, or connect to Holter monitors that can fit in the user's pocket. device.
Pasquali's lab introduced carbon nanotube fibers in 2013. Since then, fibers containing tens of billions of nanotubes each have been studied to repair bridges in damaged hearts, as electrical interfaces to the brain, for cochlear implants, as flexible antennas, and for automotive and aerospace applications. Their development is also part of the Rice-based Carbon Center, a multi-university research initiative led by Rice and launched in 2019.
Els filaments de nanotubs originals tenien unes 22 micres d'amplada, massa prims per a una màquina de cosir. Es va utilitzar un fabricant de cordes per crear el fil cosible, bàsicament tres paquets de set filaments cadascun, teixits a aproximadament la mateixa mida que el fil normal, va dir Taylor.
"We worked with a guy who sold a little machine designed to make ropes for model boats," says Taylor, who initially tried to weave the thread by hand with limited success. "He was able to make us a mid-scale device that could do that."
El patró en zig-zag es pot ajustar per tenir en compte la quantitat d'estirament que pot tenir una roba esportiva o un altre teixit, va dir. Taylor va dir que l'equip està treballant amb el doctor Mehdi Razavi i els seus col·legues del Texas Heart Institute per esbrinar com maximitzar el contacte amb la pell.
Les fibres teixides a la tela també es podrien utilitzar per incrustar antenes o LED, van dir els investigadors. Lleugeres modificacions a la geometria de la fibra i l'electrònica associada podrien eventualment permetre a la roba controlar els signes vitals, l'esforç o la freqüència respiratòria.
Other potential uses could include human-machine interfaces in cars or soft robots, or as antennas, health monitors and bulletproof protection for military uniforms, Taylor noted. "We demonstrated with a collaborator a few years ago that carbon nanotube fibers dissipate energy better per unit weight than Kevlar fibers, and that's without some of our later progress in tensile strength," she said. "
"We're seeing this material play a role in more and more applications after 20 years of development in laboratories around the world," Pasquali said. "Carbon nanotubes are a natural building block for wearable devices due to their combination of electrical conductivity, good skin contact, biocompatibility and softness."
El mercat dels wearables, tot i que és relativament petit, podria ser un punt d'entrada per a una nova generació de materials sostenibles que es poden extreure dels hidrocarburs mitjançant la divisió directa, un procés que també produeix hidrogen net, va dir. El desenvolupament d'aquest material és un focus del Carbon Center.
"We are in the same situation as solar cells were decades ago," Pasquali said. "We need application leaders that can power scale-up of production and improve efficiency."
