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. .
Según los investigadores, las fibras son tan conductoras como los cables de metal, pero son lavables, cómodas y mucho menos propensas a romperse cuando el cuerpo está en movimiento. En general, sus prendas mejoradas fueron mejores para recopilar datos que los monitores de correa de pecho-estándar que tomaron medidas de campo en los experimentos. Cuando se combinaron con monitores de electrodos médicos comerciales, las prendas de nanotubos de carbono funcionaron ligeramente mejor en los 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."
Los investigadores señalan que las fibras de nanotubos son suaves y elásticas, y la ropa que las incorpora se puede lavar a máquina. Estas fibras se pueden coser a máquina sobre la tela como un hilo estándar. El patrón de costura en zigzag permite que las telas se estiren sin romperlas.
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.
Los filamentos de nanotubos originales tenían alrededor de 22 micrones de ancho, demasiado delgados para que los manejara una máquina de coser. Se utilizó un fabricante de cuerdas para crear el hilo de coser, básicamente tres paquetes de siete filamentos cada uno, tejidos aproximadamente del mismo tamaño que el hilo normal, dijo 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 patrón en zig-zag se puede ajustar para tener en cuenta cuánto se puede estirar una ropa deportiva u otra tela, dijo. Taylor dijo que el equipo está trabajando con el Dr. Mehdi Razavi y sus colegas del Texas Heart Institute para descubrir cómo maximizar el contacto con la piel.
Las fibras tejidas en la tela también podrían usarse para incrustar antenas o LED, dijeron los investigadores. Ligeras modificaciones a la geometría de la fibra y la electrónica asociada podrían eventualmente permitir que la ropa controle los signos vitales, el esfuerzo o la frecuencia respiratoria.
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 mercado de los wearables, si bien es relativamente pequeño, podría ser un punto de entrada para una nueva generación de materiales sostenibles que se pueden extraer de los hidrocarburos mediante división directa, un proceso que también produce hidrógeno limpio, dijo. Desarrollar este material es un enfoque 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."
