Fibers Flexible Enough to Deliver Optical and Electrical Impulses in a Spinal Cord

Achievement date: 

A flexible and stretchable fiber that can deliver light pulses for neural stimulation, along with electrical connections for neural recording, was developed by a team of researchers affiliated with the Center for Neurotechnology (CNT). Based at the University of Washington (UW), the CNT is an NSF-funded Engineering Research Center (ERC)


A rubber-like fiber that can flex and stretch while delivering optical impulses and electrical stimulation promises to ease the study of such signals in the spine, which itself flexes and stretches. Fibers used today in research are stiffer and more brittle, and could damage delicate tissues in the spinal cord.


The team combined a newly developed transparent elastomer to carry optical signals, which it coated with a mesh of silver nanowires for carrying electrical signals. To process the transparent elastomer, researchers embedded the material in a polymer cladding where they could draw the material into a fiber. The cladding dissolved after the drawing process, leaving a fiber that proved highly stretchable as well as flexible.

The more flexible fiber will allow scientists studying spinal cord injuries or disease to use smaller animals, such as the mice that are more readily available and come in genetically modified strains. Without the flexible fibers, researchers usually must use larger animals in their studies because the larger nerve fibers can withstand the more rigid wires used for stimulus and recording.

The team hopes one day that similar, flexible fibers could overcome spinal-cord injuries in humans.