Researchers have built a tiny mesh-like electronic sensor, rolled it up into a hypodermic needle and injected it into the brain. The device taking this fantastic electronic voyage may soon be able to zap tumors, repair damaged spinal cords or even connect parts of the brain like an artificial synapse.
The key finding is that the sensor and mesh combination is so small and bendy that it doesn't cause any damage to the surrounding brain tissue, something that often plagues surgical procedures done with a needle, knife or other type of probe.
"If one is thinking of trying to change the way one does long term brain implants, it could be a really big deal," said Charles Lieber, chemistry professor at Harvard University and lead author on the new paper published in the journal Nature Nanotechnology. "You can promote a positive interaction versus creating a reactive response which shields the electronics."
Lieber said the stiffness of flexible electronic sensor is four to six orders magnitude bigger than current electronics. "Cells can penetrate through this," he said. As a result, the sensor doesn't provoke a response by the body's immune system.
The mesh is made of a polymer material with electronics embedded inside. After an injection several centimeters into the brain of a laboratory mouse, the scientists were able to monitor electronic brain signals.
Zhenan Bao, professor of chemical engineering at Stanford University who is also building injectable electronics, said the experiment was "an amazing piece of work."
"The concept is ingenious," Bao said via e-mail. "I am impressed that they were able to inject even the nanowire transistors with very high yield."
"One big challenge with implantable devices is that the implanting procedure can be very invasive," said Bao. "This method makes implanting straightforward and probably almost painless. This is a game changer for implantable devices. I imagine this concept will be broadly applicable to other applications where a thin electronic sheet needs to be embedded."
The authors of the paper say next step is to use the mesh system to deliver living stem cells that may help repair damaged sections of the brain or perhaps a multifunction electronic device, according to Lieber.
Lieber's experiment was done on laboratory mice. Getting approval for such work in the human patients is still a few years away, he said.