A Thin Film Transistor Backplane for Scalable Chronic Neural Interfaces

Area of Science:

• Neuroscience
• Materials Science
• Electrical Engineering

Background:

• Scaling neural interfaces to higher channel counts is crucial for advanced neuroscience research and clinical applications.
• Current passive arrays face limitations in channel density and interconnect complexity for large-scale recordings.
• Integrating active electronics at sensing sites offers a path to overcome these limitations.

Purpose of the Study:

• To develop a monolithic flexible thin-film integrated circuit platform for active neural sensing.
• To improve scalability for high-channel-count neural interface applications.
• To demonstrate the long-term stability and performance of the active neural sensing platform.

Main Methods:

• Utilized dual-gate amorphous indium gallium zinc oxide transistors on polyimide substrates.
• Implemented in-pixel transconductance amplification and row-column time-division multiplexing.
• Employed co-optimization of device architecture, contact engineering, and hybrid thin-film encapsulation for device longevity.

Main Results:

• Achieved stable operation with projected lifetimes exceeding 38 years under accelerated aging.
• Demonstrated negligible thermal burden during acute and chronic in vivo rat studies.
• Recorded stable, sensory-evoked signals over 30 days, even with tissue encapsulation.

Conclusions:

• Display-inspired flexible thin-film electronics provide a scalable solution for next-generation neural interfaces.
• The developed platform offers a promising approach for high-density, long-term neural recording.
• This technology has the potential to significantly advance brain-computer interfaces and neuroscience research.