A novel method of fabricating high channel density neural array for large neuronal mapping

With the advent of silicon micromachining, biomaterials and advanced technology, it is becoming possible to fabricate more sophisticated implantable neural arrays that can record from and stimulate neurons and nerve axons in the central and peripheral nervous system. To access large portion of human brain, neural arrays with hundreds of channels are needed. The Utah Electrode Array (UEA) is one example of such a neural interface that can selectively communicate with large numbers of individual neurons. The UEA is a 10×10 matrix with 100 channels/active sites. Though the UEA provides high selectivity in recording and stimulation, it has only one active site per shaft and the active site is at the tip of the shaft. In this work, we present a novel method of fabricating multiple active sites along and around the shaft of the UEA that will lead to a high channel density neural array, but with the same footprint as of the standard UEA. This new array, the Utah Multisite Electrode Array (UMEA), is capable to have 9 channels per shaft with channel density of 56.25 sites/mm², which is 9 times more than that of the conventional UEA. It is envision that the UMEA will offer several advantages such as large volume of human brain can be mapped and different layers of human cortex can be accessed.