Electronics with switchable flexibility for 3D conforming neural interfaces

Area of Science:

• Bioelectronic systems
• Neuroscience
• Materials science

Background:

• Cortical folds in large primates limit neural information access by current interface devices.
• Existing neural interfaces struggle with nonpenetrative, deep tissue coverage of complex brain structures.

Purpose of the Study:

• To develop a novel bioelectronic system, sFlex-Fold, for nonpenetrative, 3D neural interfacing.
• To enable large-area coverage of both gyri and sulci within the brain's intricate folds.
• To achieve tissue-matching mechanical compliance for high-quality neural signal acquisition.

Main Methods:

• Designed a switchable flexibility bioelectronic system using an AI-designed liquid metal alloy (LM-alloy).
• Leveraged the phase change of the LM-alloy around 36.2°C for tunable mechanical response.
• Patterned the LM-alloy with ~10-micrometer resolution for intricate circuit layouts.
• Demonstrated nondestructive implantation and large-area coverage (>80 cm²) in rodent and porcine models.

Main Results:

• sFlex-Fold exhibits switchable flexibility, transitioning from rigid to highly compliant upon in vivo contact.
• Achieved a three-order-of-magnitude reduction in the device's effective modulus.
• Enabled nonpenetrative, 3D access to deep cortical sulci and gyri.
• Demonstrated high-quality electrical interfacing with large-area, tissue-compliant coverage.

Conclusions:

• sFlex-Fold provides a unique solution for accessing neural information in complex brain structures.
• The system's adaptable mechanical properties and 3D morphing capabilities overcome limitations of traditional neural interfaces.
• This technology facilitates high-fidelity neural interfacing for advanced neuroscience research and potential clinical applications.