Novel glass microprobe arrays for neural recording

Abstract

The probe array is a useful tool for neurophysiology to detect and record neural signals. Thus, the better understanding of neural systems can be achieved. Microfabricated probes have been widely used since fine-spacing probes with well-defined electrodes in smaller footprint can be created. This study presents a novel process to realize glass 2D-microprobe array. Dielectric material like glass can provide better signal isolation capability and biocompatibility. The through silicon vias (TSVs) can also be integrated with the glass 2D-microprobe using the micromachining process. The vertical integration of chips containing glass 2D-microprobe array is realized using these silicon TSVs. The 3D-microprobe array can be easily implemented after vertical assembly of 2D-microprobe chips using bonding. In application, the 2D glass microprobe is fabricated and characterized with a low impedance of 439kΩ at 1kHz. The action potential of crayfish's nerve cord has successfully been recorded using the glass microprobe with peak-to-peak amplitude of 228μV, and SNR of 46.42. The spontaneous spike of rat's cortex has also been recorded by the glass microprobe with peak-to-peak amplitude of 90μV, and SNR of 19.72.