Multimodal Neural Probes with Small Form Factor Based on Dual-Side Fabrication

Monitoring both individual neuronal spikes and neurotransmitters released from a specific brain region plays a significant role in understanding neuronal circuits and brain functionalities. While polymer neural probe offers distinctive advantages of flexibility, optical transparency, and biocompatibility, achieving high-density recording with multifunctionalities and multimodality is still a challenge due to limited microfabrication techniques. Here, a multimodal polymer neural probe array based on a dual-side fabrication process with the potential for high-density neural recording and electrochemical neurotransmitter detection is presented. The developed dual-side fabrication allows the placement of a larger number of microelectrodes and multimodal sensors without increasing the probe dimension by utilizing both sides of the shank. Using the dual-side fabrication, a dual-sided SU-8 neural probe array is fabricated which consists of an array of gold and platinum microelectrodes and a micron-scale three-electrode system. Moreover, the design space of the micron-scale three-electrode systems on the dual-side neural probe is explored. Through successful in vivo neural spike recording and dopamine (DA) measurements in a brain phantom using the fabricated dual-side neural probe, it is confirmed that the dual-sided microfabrication is a reliable and viable solution.

Automated summary

In this study, a multimodal polymer neural probe array based on a dual-side fabrication process is presented, which has the potential for high-density neural recording and electrochemical neurotransmitter detection.