A three-dimensional flexible microprobe array for neural recording assembled through electrostatic actuation.

Area of Science:

• Neuroscience
• Biomedical Engineering
• Materials Science

Background:

• Recording neural signals requires precise and stable microelectrodes.
• Existing microprobes face challenges with micromotion and tissue encapsulation.
• Three-dimensional (3D) probes offer potential advantages for complex neural structures.

Purpose of the Study:

• To design, fabricate, and test a novel 3D flexible microprobe for neural signal recording.
• To evaluate the probe's performance in recording from a crayfish lateral giant nerve fiber.
• To assess the probe's biocompatibility and mechanical properties.

Main Methods:

• Fabrication of 3D flexible microprobes using SU-8 and Parylene technology.
• Electrostatic actuation for folding planar probes into 3D structures.
• Testing probe performance in recording neural signals from American crayfish and evaluating biocompatibility.

Main Results:

• Successfully recorded neural signals from a lateral giant cell with an action potential amplitude of 343 µV.
• Achieved a high signal-to-noise ratio of 30.22 ± 3.58 dB.
• Demonstrated reduced micromotion and tissue encapsulation compared to traditional probes.
• Cytotoxicity tests indicated satisfactory biocompatibility and non-toxicity.

Conclusions:

• The novel 3D flexible microprobe is effective for recording neural signals with high fidelity.
• The probe's design minimizes adverse tissue reactions, enabling chronic implantation.
• This technology facilitates investigation of neural circuits and cooperative neuronal activity.