Rice University and Texas Heart Institute: Damaged Hearts Rewired with Nanotube Fibers

Today we want to share the following press release from Rice University in order to shine a spotlight on a newly-published paper about an exciting medical application of carbon nanotube fibers! This work was done by a collection of researchers at Rice University and the Texas Heart Institute in Houston, the University of Illinois at Chicago, and the Città della Speranza Pediatric Research Institute in Padua, Italy. Rice alumnus Colin Young, one of the co-authors on the paper, is currently a member of the DexMat team!

Damaged hearts rewired with nanotube fibers

Texas Heart doctors confirm Rice-made, conductive carbon threads are electrical bridges

HOUSTON – (Aug. 13, 2019) – Thin, flexible fibers made of carbon nanotubes have now proven able to bridge damaged heart tissues and deliver the electrical signals needed to keep those hearts beating.

Scientists at Texas Heart Institute (THI) report they have used biocompatible fibers invented at Rice University in studies that showed sewing them directly into damaged tissue can restore electrical function to hearts.
Rice University Professor Matteo Pasquali, left, and Dr. Mehdi Razavi of the Texas Heart Institute check a thread of carbon nanotube fiber invented in Pasquali's Rice lab. They are collaborating on a method to use the fibers as electrical bridges to restore conductivity to damaged hearts. (Credit: Texas Heart Institute)

Rice Professor Matteo Pasquali, left, and Dr. Mehdi Razavi of the Texas Heart Institute check a thread of carbon nanotube fiber invented in Pasquali’s Rice lab. They are collaborating on a method to use the fibers as electrical bridges to restore conductivity to damaged hearts. Courtesy of the Texas Heart Institute

“Instead of shocking and defibrillating, we are actually correcting diseased conduction of the largest major pumping chamber of the heart by creating a bridge to bypass and conduct over a scarred area of a damaged heart,” said Dr. Mehdi Razavi, a cardiologist and director of Electrophysiology Clinical Research and Innovations at THI, who co-led the study with Rice chemical and biomolecular engineer Matteo Pasquali.

“Today there is no technology that treats the underlying cause of the No. 1 cause of sudden death, ventricular arrhythmias,” Razavi said. “These arrhythmias are caused by the disorganized firing of impulses from the heart’s lower chambers and are challenging to treat in patients after a heart attack or with scarred heart tissue due to such other conditions as congestive heart failure or dilated cardiomyopathy.”

Results of the studies on preclinical models appear as an open-access Editor’s Pick in the American Heart Association’s Circulation: Arrhythmia and Electrophysiology. The association helped fund the research with a 2015 grant.

The research springs from the pioneering 2013 invention by Pasquali’s lab of a method to make conductive fibers out of carbon nanotubes. The lab’s first threadlike fibers were a quarter of the width of a human hair, but contained tens of millions of microscopic nanotubes. The fibers are also being studied for electrical interfaces with the brain, for use in cochlear implants, as flexible antennas and for automotive and aerospace applications.

The experiments showed the nontoxic, polymer-coated fibers, with their ends stripped to serve as electrodes, were effective in restoring function during monthlong tests in large preclinical models as well as rodents, whether the initial conduction was slowed, severed or blocked, according to the researchers. The fibers served their purpose with or without the presence of a pacemaker, they found.
(Credit: James Philpot/Texas Heart Institute)

Illustration by James Philpot/Texas Heart Institute

In the rodents, they wrote, conduction disappeared when the fibers were removed.

“The reestablishment of cardiac conduction with carbon nanotube fibers has the potential to revolutionize therapy for cardiac electrical disturbances, one of the most common causes of death in the United States,” said co-lead author Mark McCauley, who carried out many of the experiments as a postdoctoral fellow at THI. He is now an assistant professor of clinical medicine at the University of Illinois College of Medicine.

“Our experiments provided the first scientific support for using a synthetic material-based treatment rather than a drug to treat the leading cause of sudden death in the U.S. and many developing countries around the world,” Razavi added.

Many questions remain before the procedure can move toward human testing, Pasquali said. The researchers must establish a way to sew the fibers in place using a minimally invasive catheter, and make sure the fibers are strong and flexible enough to serve a constantly beating heart over the long term. He said they must also determine how long and wide fibers should be, precisely how much electricity they need to carry and how they would perform in the growing hearts of young patients.
Researchers at Texas Heart Institute and Rice University have confirmed that flexible, conductive fibers made of carbon nanotubes can bridge damaged tissue to deliver electrical signals and keep hearts beating despite congestive heart failure or dilated cardiomyopathy or after a heart attack. (Credit: Texas Heart Institute)

Researchers at Texas Heart Institute and Rice University have confirmed that flexible, conductive fibers made of carbon nanotubes can bridge damaged tissue to deliver electrical signals and keep hearts beating despite congestive heart failure or dilated cardiomyopathy or after a heart attack. Courtesy of the Texas Heart Institute

“Flexibility is important because the heart is continuously pulsating and moving, so anything that’s attached to the heart’s surface is going to be deformed and flexed,” said Pasquali, who has appointments at Rice’s Brown School of Engineering and Wiess School of Natural Sciences.

“Good interfacial contact is also critical to pick up and deliver the electrical signal,” he said. “In the past, multiple materials had to be combined to attain both electrical conductivity and effective contacts. These fibers have both properties built in by design, which greatly simplifies device construction and lowers risks of long-term failure due to delamination of multiple layers or coatings.”

Razavi noted that while there are many effective antiarrhythmic drugs available, they are often contraindicated in patients after a heart attack. “What is really needed therapeutically is to increase conduction,” he said. “Carbon nanotube fibers have the conductive properties of metal but are flexible enough to allow us to navigate and deliver energy to a very specific area of a delicate, damaged heart.”

Rice alumna Flavia Vitale, now an assistant professor of neurology and of physical medicine and rehabilitation at the University of Pennsylvania, and Stephen Yan, a graduate student at Rice, are co-lead authors of the paper.

Co-authors are Colin Young and Julia Coco of Rice; Brian Greet of THI and Baylor St. Luke’s Medical Center; Marco Orecchioni and Lucia Delogu of the Città della Speranza Pediatric Research Institute, Padua, Italy; Abdelmotagaly Elgalad, Mathews John, Doris Taylor and Luiz Sampaio, all of THI; and Srikanth Perike of the University of Illinois at Chicago. Pasquali is the A.J. Hartsook Professor of Chemical and Biomolecular Engineering, a professor of materials science and nanoengineering and of chemistry.

The American Heart Association, the Welch Foundation, the Air Force Office of Scientific Research, the National Institutes of Health and Louis Magne supported the research.

Read the paper at https://www.ahajournals.org/doi/full/10.1161/CIRCEP.119.007256

This news release can also be found online at https://www.texasheart.org/news/ and https://news.rice.edu/2019/05/29/damaged-hearts-rewired-with-nanotube-fibers/

 

Source: Rice University News & Media

Carbon Nanotube AUX Cable

In this video, we demonstrate an auxiliary cable made with carbon nanotube (CNT) conductors and shielding. The cable has two CNT yarn conductors that are insulated with a nylon braid and then shielded with a CNT fiber braid. The sound quality is great and highlights the tremendous potential for CNT materials in high-end audio cables!

Chopping Carbon Nanotube Yarn with an Axe

Some time ago, we uploaded a video showing how well a sample of our carbon nanotube film was able to hold up to an impact from a blade. In this video, we take things a step further by trying to cut some of our carbon nanotube yarn with an axe!

Spoiler warning: it survives better than that piece of wood does.

Flexible CNT Antennas from Rice U

Antennas of flexible nanotube films an alternative for electronics

HOUSTON – (June 10, 2019) – Antennas made of carbon nanotube films are just as efficient as copper for wireless applications, according to researchers at Rice University’s Brown School of Engineering. They’re also tougher, more flexible and can essentially be painted onto devices.

The Rice lab of chemical and biomolecular engineer Matteo Pasquali tested antennas made of “shear-aligned” nanotube films. The researchers discovered that not only were the conductive films able to match the performance of commonly used copper films, they could also be made thinner to better handle higher frequencies.

Metal-free antennas made of thin, strong, flexible carbon nanotube films are as efficient as common copper antennas, according to a new study by Rice University researchers. (Credit: Jeff Fitlow/Rice University)

Metal-free antennas made of thin, strong, flexible carbon nanotube films are as efficient as common copper antennas, according to a new study by Rice University researchers. (Credit: Jeff Fitlow/Rice University)

The results detailed in Applied Physics Letters advance the lab’s previous work on antennas based on carbon nanotube fibers.

The lab’s shear-aligned antennas were tested at the National Institute of Standards and Technology (NIST) facility in Boulder, Colorado, by lead author Amram Bengio, who carried out the research and wrote the paper while earning his doctorate in Pasquali’s lab. Bengio has since founded a company to further develop the material.

At the target frequencies of 5, 10 and 14 gigahertz, the antennas easily held their own with their metal counterparts, he said. “We were going up to frequencies that aren’t even used in Wi-Fi and Bluetooth networks today, but will be used in the upcoming 5G generation of antennas,” he said.

Bengio noted other researchers have argued nanotube-based antennas and their inherent properties have kept them from adhering to the “classical relationship between radiation efficiency and frequency,” but the Rice experiments with more refined films have proved them wrong, allowing for the one-to-one comparisons.

To make the films, the Rice lab dissolved nanotubes, most of them single-walled and up to 8 microns long, in an acid-based solution. When spread onto a surface, the shear force produced prompts the nanotubes to self-align, a phenomenon the Pasquali lab has applied in other studies.

Bengio said that although gas-phase deposition is widely employed as a batch process for trace deposition of metals, the fluid-phase processing method lends itself to more scalable, continuous antenna manufacturing.

The test films were about the size of a glass slide, and between 1 and 7 microns thick. The nanotubes are held together by strongly attractive van der Waals forces, which gives the material mechanical properties far better than those of copper.

The researchers said the new antennas could be suitable for 5G networks but also for aircraft, especially unmanned aerial vehicles, for which weight is a consideration; as wireless telemetry portals for downhole oil and gas exploration; and for future “internet of things” applications.

Rice University alumnus Amram Bengio holds a flexible nanotube film antenna. The antenna, which has proven as efficient as those made of copper wire, can essentially be painted onto devices. (Credit: Jeff Fitlow/Rice University)
Rice University alumnus Amram Bengio holds a flexible nanotube film antenna. The antenna, which has proven as efficient as those made of copper wire, can essentially be painted onto devices. (Credit: Jeff Fitlow/Rice University)

“There are limits because of the physics of how an electromagnetic wave propagates through space,” Bengio said. “We’re not changing anything in that regard. What we are changing is the fact that the material from which all these antennas will be made is substantially lighter, stronger and more resistant to a wider variety of adverse environmental conditions than copper.”

“This is a great example of how collaboration with national labs greatly expands the reach of university groups,” Pasquali said. “We could never have done this work without the intellectual involvement and experimental capabilities of the NIST team.”

Co-authors of the paper are Rice graduate student Lauren Taylor, research group manager Robert Headrick and alumni Michael King and Peiyu Chen; Damir Senic, Charles Little, John Ladbury, Christian Long, Christopher Holloway, Nathan Orloff and James Booth, all of NIST; and former Rice faculty member Aydin Babakhani, now an associate profess or of electrical and computer engineering at UCLA. Pasquali is the A.J. Hartsook Professor of Chemical and Biomolecular Engineering, professor of chemistry and of materials science and nanoengineering. Bengio is the founder and chief operating officer of Wootz, L.L.C.

The Air Force Office of Scientific Research, the Department of Defense and a National Defense Science and Engineering Graduate Fellowship supported the research.

 

Source: Rice University News & Media

New High Strength Yarn Product Release

In this video we introduce a high strength grade of 200 micron diameter CNT yarn to the catalog of DexMat yarn products! The high strength yarn has a breaking force of well over 3 kg and is about 50 % stronger than its predecessor. The tensile strength of this yarn is 1 GPa, and it is also very lightweight and highly flexible. Our high strength yarn is now available for purchase at the DexMat online store.

New Carbon Nanotube Film Product Release

In this video we introduce 10 micron thick film to the catalog of DexMat film products and show how the film can be easily processed on standard winding equipment. CNT films have tremendous potential in applications ranging from EMI shielding in cables/electronics, to thermal interface materials, to heating elements or conductive materials in clothing or e-textiles. High conductivity, high strength, 10 micron thick film is now available for purchase at the DexMat online store!

Happy Pi Day!

Here we show off the difference between Pi grams of copper wire and Pi grams of our carbon nanotube yarn.

Full disclosure: some of the difference in length here is due to the carbon nanotube yarn being thinner. The copper wire in this video is 1.2 mm in diameter; the carbon nanotube yarn ranged from 0.7 mm to 1 mm in diameter. The length difference is so extreme, however, because of the difference in density between the two materials, which is close to a factor of 9.

Happy Pi Day!

Plating Carbon Nanotube Yarn with Copper

In this video we provide a brief look at some of the experimental work we are doing to develop new products at DexMat. Here, we are using an electroplating process to coat our carbon nanotube yarn with a layer of copper. This process may allow us to create a useful hybrid material, combining the conductivity of metallic copper with the strength and durability of our lightweight carbon nanotube yarn.

Braiding CNT Fibers

In this video, we demonstrate the process that we use for braiding carbon nanotube fibers to make EMI shielding braids or braided CNT yarns. These braids are lightweight and highly flexible. They are also more conductive than stainless steel fiber braids and much stronger than copper wire.

CNT Yarn & Tape: Resistance Measurement

A demonstration of the methods & tools we typically use to measure the electrical resistance of our carbon nanotube yarns & tapes.