Researchers from Oak Ridge National Laboratory have developed a method of bundling thousands of nano-sized glass tubes, each having a conducting carbon core. Among other things, the technology may make possible artificial neural bundles to interface with prostheses and for future surgeries of the nervous system.
Ultimately, the goal is to duplicate the function of a living system by combining the existing technology of glass fiber drawing with the multi-functionality of sub-micron (0.4 micron) scale carbon nanotubes, according to Ivanov ]Ilia Ivanov, researcher at the Center for Nanophase Materials Sciences Division, ORNL–ed.], who described the process.
“We make this material in a way similar to what you may have done in high school when making a glass capillary over a Bunsen burner,” Ivanov said. “There, you would take the glass tube, heat it up and pull, or draw, as soon as the glass became soft.”
Ivanov and John Simpson of the Measurement Science and Systems Engineering Division are doing something similar except they use thousands of glass tubes filled with carbon nanotube powder. After several draw cycles, they demonstrated that they could make fibers just four times thicker than a human hair containing 19,600 sub-micron channels with each channel filled with conducting carbon. Each carbon nanotube-containing channel is electrically insulated from its neighbors by glass so it can be used as an individual communication channel.
“The human hand has a density of receptors at the fingertips of about 2,500 per square centimeter and about 17,000 tactile receptors in the hand,” Ivanov said. “So in terms of density of channels, we are already in the range needed for 17,000 receptors in the hand.”
The next steps are to make these channels highly conductive and then show sensor communication through individual channels.
Image caption: An artificially colored scanning electron microscope photograph of one of the channels with the carbon nanotube bundle (yellow-green) protruding from it, above the surface of the glass (blue).
Press release: New ORNL carbon composite holds promise for bionics…
Abstract in Nanotechnology: Processing of loose carbon nanotubes into isolated, high density submicron channels