Injectable electronic devices that could be inserted into human brains or bodies have been developed by American researchers, promising a breakthrough in the treatment of disabilities.
The invention is a product of the Charles Lieber laboratory at Harvard University and is described in the latest issue of the Nature Nanotechnology journal.
By creating nanoscale electronic scaffolds that could be injected via a syringe, the researchers gained the ability to stimulate the tissue, monitor neural activity and even promote the regeneration of neurons.
The team led by Chemistry Professor Charles Lieber believes the technique could revolutionise treatment of neurodegenerative diseases and paralysis.
"This opens up a completely new frontier where we can explore the interface between electronic structures and biology,” said Lieber. “For the past thirty years, people have made incremental improvements in micro-fabrication techniques that have allowed us to make rigid probes smaller and smaller, but no one has addressed this issue - the electronics/cellular interface - at the level at which biology works."
Leiber’s team previously demonstrated that scaffolds could be used to create ‘cyborg’ tissue, when cardiac or nerve cells were grown with embedded scaffolds. Researchers were then able to use the devices to record electrical signals generated by the tissues and to measure changes in those signals as they administered cardio or neuro-stimulating drugs.
"We were able to demonstrate that we could make this scaffold and culture cells within it, but we didn't really have an idea how to insert that in to pre-existing tissue," Lieber said. "But if you want to study the brain or develop the tools to explore the brain-machine interface, you need to stick something into the body.”
Lieber believes that his devices - flexible and almost invisible - would perform much better than existing neuro-stimulation techniques.
"Existing techniques are crude, relative to the way the brain is wired," Lieber explained. "Whether it's a silicon probe or flexible polymers, they cause inflammation in the tissue that requires periodically changing the position or the stimulation. But with our injectable electronics, it's as if it's not there at all. They are one million times more flexible than any state-of-the-art flexible electronics and have subcellular feature sizes. They're what I call 'neuro-philic' - they actually like to interact with neurons."
The method used to produce the devices is surprisingly simple, the researcher said. It starts with a dissolvable layer deposited on a substrate, around which a mesh of nanowires is wound. The first layer is then dissolved leaving the flexible injectable mesh.
After insertion in to the body, the device can be connected to standard measurement electronics so that the integrated devices can be addressed and used to stimulate or record neural activity.
"These types of things have never been done before, from both a fundamental neuroscience and medical perspective," Lieber said. "It's really exciting, there are a lot of potential applications."
Harvard's Office of Technology Development has filed for a provisional patent on the technology and is actively seeking commercialisation opportunities.