Flexible Neural Probe with an Optimized Electrode Density for Neutral Investigations

Area of Science:

• Neuroscience
• Materials Science
• Electrical Engineering

Background:

• Silicon-based neural probes offer high density but are expensive and complex.
• Flexible neural probes using flexible printed circuit board (FPCB) technology are cost-effective but have low electrode density.
• Limited electrode density in FPCB probes hinders scalability and accessibility in neuroscience research.

Purpose of the Study:

• To present a fabrication-optimized flexible neural probe with significantly enhanced electrode density.
• To improve the cost-effectiveness and scalability of neural probes for broader neuroscience applications.
• To overcome the limitations of existing flexible neural probes regarding electrode density and signal quality.

Main Methods:

• Optimized line width and spacing for increased electrode density within standard FPCB processes.
• Incorporated a stiffener layer to enhance substrate planarity and probe handling.
• Applied a 20% overetching technique to improve pattern fidelity and reliability of the probe's features.

Main Results:

• Achieved a considerable increase in electrode density, tripling the number of recordable neural signals.
• Maintained high-signal quality and demonstrated electrical and mechanical stability of the fabricated probes.
• Reported a fabrication yield of 73% over 200 samples, indicating scalability and reliability.

Conclusions:

• The optimized flexible neural probe offers a cost-effective and scalable solution for neural recording.
• Enhanced electrode density and reliable performance improve accessibility for neuroscience research, especially in resource-limited environments.
• This advancement facilitates broader and more efficient investigations of neural networks and brain function.