Ultrahigh-Density 256-Channel Neural Sensing Microsystem Using TSV-Embedded Neural Probes

Area of Science:

• Neuroscience
• Biomedical Engineering
• Microsystems Engineering

Background:

• Accurate neural signal acquisition is vital for understanding brain function.
• Existing neural sensing systems face challenges in channel density, size, and power consumption.
• Highly integrated microsystems are needed for advanced brain-computer interfaces and neurological research.

Purpose of the Study:

• To develop and demonstrate a highly integrated 256-channel neural sensing microsystem.
• To achieve high-density neural signal recording within a compact area.
• To evaluate the microsystem's performance in both in-vitro and in-vivo animal models.

Main Methods:

• Fabrication of a 2.5-D through-silicon-via (TSV) integrated microsystem.
• Integration of dissolvable microneedles, TSV-embedded microprobes, neural amplifiers, and analog-to-digital converters.
• Recording of electrocorticography (ECoG) and local field potential (LFP) signals.
• In-vivo implantation into rat brains for somatosensory evoked potentials (SSEPs) recording.

Main Results:

• A 256-channel neural sensing microsystem with a 5x5 mm² sensing area was successfully developed.
• The microsystem achieved a neural amplifier gain of 57.8 dB with low power consumption (9.8 μW/channel).
• Total power consumption for 256 channels was 3.79 mW.
• Demonstrated successful recording of SSEPs in rat brains using a smaller 6x4 mm² version of the microsystem.

Conclusions:

• The presented 2.5-D TSV integrated neural sensing microsystem offers high channel density and low power consumption.
• The device is capable of acquiring detailed neural signals, including ECoG, LFP, and SSEPs.
• This technology holds significant potential for advancing neurological research and clinical applications.