Glass-Embedded Nerve Stimulator Electrodes for High-Density Arrays
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Solution Overview
Problem
Existing retinal microelectrode stimulators face challenges in achieving high-density stimulation electrode arrays due to limitations in processing rigid materials and the resulting increased surgical trauma from numerous wirings.
Innovation Solution
A nerve stimulator with a glass substrate and metal pins forming high-density stimulation electrodes, where the metal pins are cut and embedded in glass, allowing for flip-chip bonding with a processing chip to reduce external wiring needs, and a manufacturing method involving metal underlayer cutting, glass filling, and thinning to create a high-density electrode array.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If rigid materials are used for stimulation electrodes and punched holes are made in substrate, then structural strength is improved, but manufacturing precision deteriorates making it difficult to achieve density exceeding 5 Pin/mm²
Solution Approach 1:
The patent changes the material parameter from rigid ceramic to flexible polyimide substrate, and changes the electrode formation method from punched holes to screen-printed metal paste. This parameter change enables achieving electrode densities exceeding 5 Pin/mm² while maintaining structural integrity through the flexible substrate and sintered metal structure.
Solution Approach 2:
The patent replaces the mechanical punching process with a screen printing process that uses metal paste and sintering. This substitution eliminates the limitations of mechanical punching on rigid substrates and enables high-density electrode patterns to be formed on flexible substrates with precise control over electrode geometry and spacing.
2Ease of manufacture
If flexible MEMS technology is used with integrally formed wiring, then ease of manufacture is improved, but device complexity increases requiring numerous wirings that increase diameter of connecting flat cable and surgical trauma
Solution Approach 1:
The patent extracts the wiring function from the substrate by using a flexible polyimide substrate that can be folded back. This allows the electrode array to be positioned on the retina while the wiring remains outside the eyeball, eliminating the need for numerous wirings to pass through the eyeball and reducing surgical trauma.
Solution Approach 2:
The patent introduces dynamic flexibility to the substrate, allowing it to be folded and positioned in different configurations. The flexible polyimide substrate can be folded back after electrode placement, enabling the device to adapt its shape and reducing the need for complex wiring arrangements, thereby simplifying the overall device structure.
3Reliability
If the number of stimulation electrodes is increased to improve stimulation effect, then stimulation effectiveness is improved, but the number of wirings increases resulting in increased diameter of connecting flat cable and larger surgical trauma
Solution Approach 1:
The patent segments the device into two functional parts: the electrode array that remains inside the eyeball on the retina, and the wiring that is folded back and positioned outside the eyeball. This segmentation allows for a high number of stimulation electrodes to be placed on the retina without requiring an equivalent number of wirings to pass through the eyeball, thus maintaining high stimulation effectiveness while minimizing surgical trauma.
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 solution enables a high-density micro-electrode array with improved stimulation effectiveness and reduced surgical trauma by using a glass substrate and metal pins, overcoming the limitations of traditional ceramic substrates and minimizing external wiring.
Implementation Method 1
performing glass filling between the metal pins cut out on the metal underlayer, so that the cut-out metal pins are completely covered with glass
Implementation Method 2
performing double-sided thinning on the metal underlayer subjected to molten glass pouring, wherein the glass covering layer on the cutting side of the metal underlayer is thinned until the metal pins are exposed
Implementation Method 3
the processing chip and the substrate are connected through flip-chip bonding
Data Source
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AI summary
A nerve stimulator and a manufacturing method thereof. The nerve stimulator includes a glass substrate (1), and a plurality of metal pins (2) provided on the substrate (1), wherein the metal pins (2) form stimulation portions on one side of the substrate (1), and the density of the metal pins (2) is greater than 15 Pin/mm2. The stimulation portions in the present nerve stimulator have a high density and a good stimulation effect. The processing method thereof is to cut out a high-density metal pin array first by using a metal underlayer, then the manufacturing method overcomes the deficiency in the prior art that it is rather difficult to manufacture a high density of nerve stimulation electrodes by using other substrates such as ceramics and the like.