Stretchable Ribbon Cable Structure for Stable Neural Interconnects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current neural interface devices face mechanical breakage and tissue damage due to stiff wire bundles, leading to inflammation and instability, as existing flexible materials like polyimide and silicon carbide are prone to fluid absorption and delamination, limiting their long-term performance.
Innovation Solution
Development of ultraflexible and stretchable polyimide ribbon cables with amorphous silicon carbide thin film interlayers, featuring a geometrical design that allows for 220% extension and robust stretchability, using photolithography-based microfabrication and a-SiC/PI layers to enhance mechanical stability and biocompatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If stiff wire bundles are used to tether neural electrodes to the skull, then mechanical strength and structural stability are improved, but tissue damage and inflammation increase due to micromotion from vascular dilation
Solution Approach 1:
The patent replaces stiff wire bundles with flexible ribbon cables constructed from thin film layers including polyimide substrate and amorphous silicon carbide encapsulation. These thin film structures provide mechanical flexibility to accommodate micromotion from vascular dilation while maintaining structural integrity, thereby reducing tissue damage and inflammation compared to traditional stiff wire bundles
Solution Approach 2:
The patent employs composite material structures combining multiple layers: polyimide substrate providing flexibility, amorphous silicon carbide providing mechanical strength and chemical inertness, and additional encapsulation layers. This composite approach achieves both flexibility to reduce micromotion damage and sufficient strength for mechanical support
2Measurement precision
If the number of electrode channels in MEAs is increased, then spatial and temporal resolution is improved, but the thickness and stiffness of wire bundles increase significantly
Solution Approach 1:
The patent uses thin film ribbon cable construction where electrical traces are patterned on flexible polyimide substrate and encapsulated in thin amorphous silicon carbide layers. This thin film approach allows high-density electrode channels to be integrated without significantly increasing the overall thickness and stiffness of the cable assembly, enabling high spatial and temporal resolution while maintaining flexibility
Solution Approach 2:
The patent transitions from traditional three-dimensional wire bundles to two-dimensional planar ribbon cable structures. This dimensional change allows electrical traces to be arranged in a flat configuration, enabling high channel density without proportionally increasing cable thickness and stiffness, thus facilitating both high measurement precision and mechanical flexibility
3Strength
If polyimide and silicon carbide materials are used for flexible ribbon cables, then flexibility is improved, but fluid absorption and interfacial delamination occur reducing long-term reliability
Solution Approach 1:
The patent creates a composite material system where amorphous silicon carbide encapsulation layers are deposited over polyimide substrate. The silicon carbide layer provides chemical inertness and resistance to fluid absorption, while the polyimide provides flexibility. This composite structure prevents fluid penetration that would cause delamination, thereby maintaining both flexibility and long-term reliability
Solution Approach 2:
The patent uses amorphous silicon carbide as an encapsulation material that creates a chemically inert barrier between the polyimide substrate and the biological environment. This inert encapsulation layer prevents fluid absorption by the polyimide and eliminates the risk of interfacial delamination, ensuring long-term stability while the polyimide maintains flexibility
4Reliability
If inorganic dielectric materials like SiO2 and SiNx are used for encapsulation, then chemical inertness is improved, but brittleness and lack of mechanical stability increase
Solution Approach 1:
The patent combines amorphous silicon carbide encapsulation with flexible polyimide substrate to create a composite structure. The silicon carbide provides chemical inertness and resistance to fluid absorption, while the polyimide substrate provides mechanical flexibility and stability. This composite approach overcomes the brittleness of pure inorganic materials while maintaining their chemical resistance
Solution Approach 2:
The patent changes the physical state and properties of the encapsulation material by using amorphous silicon carbide deposited as thin films rather than bulk inorganic materials. This parameter change allows the encapsulation layer to be sufficiently thin to accommodate flexing and bending without catastrophic failure, while still providing the desired chemical inertness and barrier properties
Data Source
AI summary
A ribbon cable including a ribbon cable body in a longitudinal (x), lateral (y) and transversal (z) dimensional axis system including a length down a central longitudinal (x) axis, where the ribbon cable body includes at least one stretchable electrically conductive material portion along at least a portion of the length, where the stretchable electrically conductive material portion is oriented in a substantially flat accordion pattern in an longitudinal (x)/lateral (y) plane down the central axis, where the stretchable electrically conductive material portion is capable of re-orienting out of the longitudinal (x)/lateral (y) plane into the traversal (z) dimension when stretched in the longitudinal (x)/lateral (y) plane..