A Multimodal, SU-8 - Platinum - Polyimide Microelectrode Array for Chronic In Vivo Neurophysiology

Area of Science:

• Neuroscience
• Biomaterials Science
• Medical Device Engineering

Background:

• Flexible, biocompatible microelectrode arrays (MEAs) are crucial for advanced neurophysiological studies.
• Current MEAs often lack the flexibility and multi-depth recording capabilities needed for comprehensive brain activity monitoring.

Purpose of the Study:

• To present the microfabrication of a novel, all-flexible, polymer-based MEA.
• To demonstrate the simultaneous recording of electrocorticographic (ECoG) signals and laminar depth recordings.
• To evaluate the in vivo functionality and long-term viability of the device.

Main Methods:

• Microfabrication of a three-dimensional, polymer-based MEA with integrated depth and surface electrodes.
• In vivo implantation in anesthetized rat brains for acute and chronic recordings.
• Analysis of recorded electrophysiological data, including local field potentials and action potentials.

Main Results:

• The flexible MEA enabled simultaneous recording of ECoG signals and high-quality depth recordings.
• The device successfully captured slow-wave thalamocortical oscillations and individual neuron action potentials.
• The implants maintained viability for detecting neural activity for at least 15 weeks.

Conclusions:

• The novel all-flexible, polymer-based MEA offers a versatile platform for advanced neurophysiological recordings.
• The device's biocompatibility and long-term stability support its use in chronic in vivo studies.
• This technology advances the potential for detailed brain activity mapping and research.