Neuroprosthetic Electrode Array Manufacturing via Extrusion Printing
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Solution Overview
Problem
Current electrode array manufacturing techniques, such as microfabrication and direct write printing, face challenges in producing flexible, biocompatible electrode arrays with precise 3D features and high viscosity material compatibility, especially for curved substrates and small line widths, leading to poorly defined features and discontinuous lines that affect electrical continuity.
Innovation Solution
A method involving pressure-driven extrusion printing to form insulating and conductive layers using biocompatible materials like silicones and conductive particles, allowing for the creation of flexible and elastic electrode arrays with precise 3D features suitable for curved surfaces, by depositing nonconductive and conductive materials in a controlled manner to form electrode arrays that can be implanted in small, curved spaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If microfabrication processes are used to create 3D features, then electrode array features can be formed, but the features are poorly defined and materials are rigid and unable to withstand flexing and bending
Solution Approach 1:
The patent replaces traditional mechanical microfabrication processes (etching, machining) with a direct-write printing approach that deposits materials layer-by-layer to form 3D features. This substitution allows for precise feature definition through controlled material deposition while using flexible polymer substrates and ink materials that can withstand bending and flexing, resolving the contradiction between feature precision and flexibility.
Solution Approach 2:
The patent uses composite material systems including flexible polymer substrates combined with conductive and insulating inks that contain various particles and polymers. These composite materials provide both the structural integrity needed for defined features and the flexibility required to withstand mechanical deformation, simultaneously addressing both requirements.
2Adaptability or versatility
If screen printing is used to produce electrode arrays, then a large range of materials can be printed, but the technique requires masks and direct contact with flat substrates and is limited for forming small 3D features
Solution Approach 1:
The patent replaces screen printing's mechanical constraint system (masks, flat substrate contact) with a non-contact or minimal-contact direct-write printing system. This allows for precise 3D feature formation through controlled material extrusion or deposition while maintaining the ability to print a wide range of materials including conductive inks, insulating materials, and structural polymers, thus resolving both requirements.
3Ease of operation
If inkjet printing is used for printing electrode arrays, then electronics can be printed on simple planar substrates, but the technique is insufficient for curved substrates and cannot print line widths smaller than 30 μm with adequate resolution
Solution Approach 1:
The patent employs a dynamic direct-write printing system where the print head can move in multiple axes and adjust its position and orientation in real-time. This dynamic capability allows for printing on curved and complex 3D substrates while maintaining precise line width control below 30 μm, overcoming the limitations of static inkjet printing systems designed for flat substrates only.
4Manufacturing precision
If aerosol jet printing is used to form electrode arrays, then small line widths as small as 5 μm can be produced, but the technique is incapable of printing nonconductive materials and prints discontinuous lines that adversely affect electrical continuity
Solution Approach 1:
The patent uses a continuous material deposition process in direct-write printing that ensures unbroken conductive pathways are formed. The system controls material extrusion to maintain continuous ink flow during printing, eliminating the discontinuous lines problem of aerosol jet printing while preserving the ability to achieve fine line widths through precise nozzle control and optimized printing parameters.
Solution Approach 2:
The patent employs parameter optimization including nozzle-to-substrate distance, printing speed, material viscosity, and extrusion pressure to achieve both fine line width (5 μm or smaller) and continuous material deposition. By carefully controlling these parameters, the system maintains electrical continuity while achieving the desired precision, resolving the contradiction between line width and continuity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method enables the production of flexible and elastic electrode arrays that can be implanted in curved spaces while maintaining electrical conductivity, with enhanced flexibility and durability, meeting biocompatibility standards and ensuring effective electrical performance.
Implementation Method 1
depositing, by pressure-driven extrusion printing, a first conductive material over a portion of the second surface of the first insulating layer
Data Source
Figure 1~2
Figure 3A~3C
Figure 3D~3F
AI summary
A method of manufacturing an electrode array includes forming a first insulating layer from a first nonconductive material; depositing, by pressure-driven extrusion printing, a first conductive material over a portion of the first insulating layer to form a first conductive layer; depositing a second nonconductive material over a portion of the first conductive layer and over an exposed portion of the first insulating layer to form a second insulating layer defining a gap exposing a portion of the first conductive layer; and depositing, by pressure-driven extrusion printing, a second conductive material into the gap and over the exposed portion of the first conductive layer to form a second conductive layer electrically connected to the first conductive layer to form at least one electrode of the electrode array.