On August 12, a research team led by Professor Bongsoo Kim of the KAIST Department of Chemistry successfully developed the world’s thinnest neural probe by using a gold nanowire, greatly enhancing the neural signal detection in brains. Using a nanowire, ten millionth of a meter wide, they were able to increase the detection sensitivity to 1000 times more than conventional neural devices, while also reducing penetration damage to the brain.

Neural probes are widely used in neuroscience to accurately assess electrical signals in the brain. However, this device causes tissue damage when inserted in the brain. Also, conventional probes have low electrical sensitivity so lack the ability to pick up detailed brain signals. The neural probe with ultra-thin nanowires however, overcame these limitations.

This special neural probe was built by synthesizing a gold nanowire and meticulously attaching it to a tungsten metal tip. The nanowire was grown by depositing gold vapors on a sapphire surface and moulding them into a thin single crystal wire 100 nanometers wide, with excellent electrical conductivity. The wire was extremely flexible as it could bend into a U-shape and revert to its original shape. With superb conductivity and flexibility, the synthesized nanowire was able to overcome the weaknesses of conventional probes.

These findings may prove to be a pivotal point in studies of chronic brain diseases. Performance tests for the neural probe were conducted on the brain of a live mouse with induced epileptic seizure. The electrode device was able to precisely locate the seizure center on the hippocampus region of a mouse brain and extract high-resolution brain activity signals.