“In the stiff state, the material is like a hard, rigid plastic, much like your CD case,” says Weder. “When the material becomes soft, it’s more like a rubber.” He says that if such a material were used to design neural electrodes, it could be engineered to respond to fluid in the brain, softening as it comes in contact with nerve tissue.
MIT’s Bizzi says that such a pliable electrode would lengthen the recording time within the brain that’s possible with neural implants, and provide valuable data for treating conditions such as Parkinson’s disease, Tourette’s syndrome, and spinal-cord injuries. “The field needs new technology to make it possible to record for longer periods of time from the brain,” says Bizzi. “If it works, it would be a godsend.”
In electrode applications, the material would only have to transform once, from rigid to soft, once inside the brain. Weder says that the cellulose-based material may be used for other applications that require shifting back and forth from stiff to softer states. “You could think about a smart cast, where you would want to stiffen your cast, but every now and then, you want to soften it up so you can move your arm,” says Weder. “So in that application, you would like a reversible material.”
Weder adds that cellulose fibers can be obtained from sources other than sea cucumbers, such as wood and cotton–an avenue that his team plans to explore.