Novel Nerve Interface Electrodes Could Be Easily Incorporated on Integrated Circuit Substrate

On the left is an electron microscope photograph of the microprobe electrode array under development. The microprobes shown here have a diameter of only 2 micrometers for low-invasive use. Moreover, these microprobes can be grown on a semiconductor substrate, as shown on the right. Image courtesy of Makoto Ishida, Toyohashi University of Technology

Continuing the neural theme of the last post…Nanowerk has reported that AIST and Toyohashi University of Technology in Japan has developed a novel electrode for a peripheral nerve interface. According to Hidekazu Kaneko from the Institute for Human Science and Biomedical Engineering at AIST, the electrode under development is expected to be able to measure the action potentials of individual nerve fibers in a peripheral nerve bundle. Earlier proposals for measuring peripheral nerve activity were based on the use of sieve electrodes, needle point holder-shaped electrodes and cuff electrodes; but these and other attempts have been unable to meet the requirement for low-invasive measurement that is also able to distinguish the activity of individual nerve fibres.

Neural interfaces used for such purposes as electroencephalography are noninvasive, but suffer from relatively poor spatial and temporal resolution of signals. The type of neural interface that uses electrodes inserted in the brain and measures neuronal activities is more effective, but might leave behind irreversible lesions in the cerebrum because of the need to implant electrodes in brain tissue. Other problems with this type of neural interface include the difficulty of obtaining information about individual organs.

The resulting electrode combines a low-invasive design with ease of incorporation on an integrated circuit substrate. Moreover, using an array of metal microelectrodes having similar recording surface area as this electrode, the researchers have confirmed the ability to take localised measurements of evoked action potentials in single peripheral nerve fibers for all-or-nothing responses.

In the future, the team hopes to enable use of this peripheral nerve electrode for measuring nerve activities and for controlling them by electrical stimulation, so that the technology can be applied to assisting and restoring organs whose functionality is impaired due to diseases and other causes.

Tags: AIST, Hidekazu Kaneko, Institute for Human Science and Biomedical Engineering, neural interface electrodes, neural interfaces