3D Flexible Neural Electrode for Curved Tissue Adhesion

The patent transitions from a two-dimensional planar electrode structure to a three-dimensional structure by forming protrusions on the electrode surface. This dimensional change enables the electrode to conform to curved and complex surface geometries, significantly improving adhesion and contact with neural tissue while maintaining compatibility with standard thin-film fabrication processes

The patent introduces curved protrusions with specific radii of curvature on the electrode surface. These curved structures allow the electrode to better match the curvature of biological surfaces such as the brain cortex, enhancing mechanical coupling and signal quality without requiring complex custom manufacturing for each application

The patent employs a composite structure consisting of multiple layers including flexible polymer substrates (such as PDMS or parylene), metallic conductive layers, and dielectric layers. This multi-material composite approach provides both the flexibility needed for conformal attachment to curved surfaces and the structural integrity required for mechanical stability and long-term reliability

By adding vertical protrusions to the thin substrate, the patent creates a three-dimensional structure that increases surface area and mechanical interlocking with the tissue while maintaining overall substrate thinness. This allows thin flexible substrates to achieve both compliance with curved surfaces and sufficient structural strength through geometric reinforcement

The patent forms protrusion patterns in the dielectric or substrate layer before depositing the metallic conductive layers. This preliminary structuring allows subsequent thin-film deposition processes to conformally coat the three-dimensional features, achieving complex 3D electrode geometries using standard sequential fabrication steps without requiring complex post-processing or assembly

The patent divides the electrode structure into distinct functional layers (substrate, dielectric, conductor, contact pads) that can be fabricated separately using optimized processes for each material system. This segmentation allows each layer to be processed independently with appropriate materials and techniques, then integrated through conformal deposition and patterning, reducing overall manufacturing complexity