European boffins connect neurons to silicon chips

European boffins connect neurons to silicon chips


The rise of the machines

European researchers have reported the creation of an interface between mammalian neurons and silicon chips.

The news is described as a crucial first step in the development of so-called 'cyborgs' that combine silicon circuits with living animals.

The ultimate applications of the technology are "potentially limitless", according to researchers involved with the NACHIP project funded by the European Commission's Future and Emerging Technologies initiative within the IST programme.

In the long term the interface could enable the creation of very sophisticated neural prostheses to combat neurological disorders, or allow the creation of organic computers that use living neurons as a CPU.

Such applications are potentially decades away, but in the much nearer term the new technology could enable very advanced and sophisticated drug screening systems for the pharmaceutical industry.

"Pharmaceutical companies could use the chip to test the effect of drugs on neurons and quickly discover promising avenues of research," said Professor Stefano Vassanelli, a molecular biologist at the University of Padua in Italy, and one of the partners in the NACHIP project.

NACHIP's core achievement was to develop a working interface between the living tissue of individual neurons and the inorganic compounds of silicon chips.

"We had a lot of problems to overcome," said Professor Vassanelli. "And we attacked the problems using two major strategies: through the semiconductor technology and the biology."

With the help of German microchip company Infineon, NACHIP placed 16,384 transistors and hundreds of capacitors on a chip just 1mm square.

The group had to find appropriate materials and refine the topology of the chip to make the connection with neurons possible.

NACHIP uses special proteins found in the brain essentially to glue the neurons to the chip, but the proteins act as more than a simple adhesive, the professor explained.

"They also provide the link between the ionic channels of the neurons and semiconductor material in a way that neural electrical signals could be passed to the silicon chip," he said.

Once there, the signal can be recorded using the chip's transistors. The neurons can also be stimulated through the capacitors, thereby enabling the two-way communication.

The project tested the device by stimulating the neurons and recording which ones fired using standard neuroscience techniques while tracking the signals coming from the chip.

The development of the interface and chip are crucial for this new technology, but problems remain. "Right now, we need to refine the way we stimulate the neurons to avoid damaging them," explained Professor Vassanelli.