A CMOS Microelectrode Array System With Reconfigurable Sub-Array Multiplexing Architecture Integrating 24,320...

Area of Science:

• Neuroscience
• Electrical Engineering
• Materials Science

Background:

• Microelectrode arrays (MEAs) are crucial for studying neural activity.
• Existing MEA systems face limitations in spatial resolution, temporal resolution, and power efficiency.
• Reconfigurable architectures and multiplexing techniques offer potential solutions to these challenges.

Purpose of the Study:

• To present a novel CMOS microelectrode array (MEA) system.
• To implement a reconfigurable sub-array multiplexing architecture using time-division multiplexing (TDM).
• To achieve high spatial and temporal resolution with low power consumption for neural signal recording.

Main Methods:

• Designed and fabricated a 128 × 190 MEA system using a 110-nm CMOS process.
• Incorporated 24,320 TiN electrodes with a 17.7 μm pitch.
• Utilized 380 column-parallel readout channels with low-noise amplifiers, programmable gain amplifiers, and 10-b SAR ADCs, employing TDM for reconfigurable sub-array multiplexing.

Main Results:

• Achieved high spatial resolution with readout channels placed outside the pixel area.
• Demonstrated flexible neural signal acquisition by configuring in-pixel memory, allowing 1 channel to handle 8–32 electrodes.
• Guaranteed temporal resolution from 5 kS/s to 20 kS/s per electrode, with low power consumption (81 μW/channel) and low input-referred noise (1.48 μV_rms without multiplexing, 5.4 μV_rms with multiplexing).

Conclusions:

• The developed CMOS MEA system with TDM reconfigurable sub-array multiplexing effectively addresses limitations of existing systems.
• The system offers a promising platform for high-density, high-resolution neural recording with improved efficiency.
• This technology has significant potential for advancing neuroscience research and neural interface applications.