Group Electroplating for Retinal Prosthesis Electrode Impedance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing retinal prosthetic devices with small electrodes face high impedance issues due to their size, leading to potential tissue damage from high charge densities, and there is a need for improved biocompatible manufacturing techniques to accommodate larger electrode arrays for better spatial resolution and tissue contact.

Innovation Solution

A scalable electroplating technique is used to deposit a continuous sheet of conductive material over a surface mount array, connecting multiple electrodes, which are then isolated, and plated with platinum black to increase surface area and reduce impedance, utilizing biocompatible materials suitable for implantation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If electrode size is reduced to fit within the macular area, then spatial resolution is improved, but impedance increases and tissue damage risk increases

Engineering Contradiction:
Improvespatial resolutionVSAvoidtissue safety
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent changes the surface morphology parameter of the electrode by electroplating with platinum black, which creates a rough surface structure. This increases the effective surface area without changing the geometric size of the electrode, thereby reducing impedance and charge density while maintaining spatial resolution

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material structure by combining the base electrode material with platinum black plating. The platinum black forms a rough, high-surface-area coating on the electrode surface, creating a composite structure that reduces impedance while maintaining the small geometric dimensions needed for high spatial resolution

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If electrode size is reduced to fit within the macular area, then spatial resolution is improved, but impedance increases

Engineering Contradiction:
Improvespatial resolutionVSAvoidelectrode impedance
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent changes the surface morphology parameter of the electrode by electroplating with platinum black, which creates a rough surface structure. This increases the effective surface area without changing the geometric size of the electrode, thereby reducing impedance while maintaining spatial resolution

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite material structure by combining the base electrode material with platinum black plating. The platinum black forms a rough, high-surface-area coating on the electrode surface, creating a composite structure that reduces impedance while maintaining the small geometric dimensions needed for high spatial resolution

Inventive Principle:
Principle #40Composite materials

3Manufacturing precision

If multiple electrodes are manufactured individually, then each electrode can be optimized, but manufacturing complexity and time increase

Engineering Contradiction:
Improveelectrode optimizationVSAvoidmanufacturing efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent merges multiple individual electrode manufacturing steps into a single group electroplating process. By providing a power supply connection to the entire electrode array simultaneously, all electrodes are plated at once rather than individually, dramatically reducing manufacturing time while maintaining consistent quality across all electrodes

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent creates a universal electroplating process that applies to all electrodes in the array simultaneously. The group electroplating method serves multiple functions: it plates all electrodes at once, ensures uniform plating thickness, and maintains consistent surface morphology across the entire array, thereby improving both productivity and manufacturing precision

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

This method efficiently decreases electrode impedance, increases surface area contact with tissues, and enhances the longevity of electrodes in corrosive bodily fluids, enabling the use of larger electrode arrays for improved retinal prosthetic devices.

Implementation Method 1

A continuous sheet of metal or other electrically conductive material can be deposited, by chemical vapor deposition (CVD) or otherwise, onto the surface mount area

Methodology Applied
Scientific EffectChemical vapor deposition: Chemical Vapour Deposition

Implementation Method 2

electroplating the electrodes using the power supply and the electrolyte solution

Methodology Applied
Scientific EffectElectroplating: Electroplating

Implementation Method 3

immersion of the other end with the electrodes in an electrolyte solution... electroplating the electrodes

Methodology Applied
Scientific EffectElectrochemical reactions: Electrolysis

Data Source

PatentEP3047709B1Micro-fabricated group electroplating technique
Publication Date: 2020.07.15 CALIFORNIA INST OF TECH
  • EP3047709B1 patent drawingFigure 1
  • EP3047709B1 patent drawingFigure 2~3
  • EP3047709B1 patent drawingFigure 4A~4E

AI summary

Methods, and devices produced by the methods, for electroplating a multitude of micro-scale electrodes that are electrically isolated from each other on a cable or other device is described. A localized area of connections on another end of the cable is shorted together by depositing a metal sheet or other conductive material over the localized area. The metal sheet is connected to a terminal of a power supply, and the electrode end of the cable is immersed in an electrolyte solution for electrodeposition by electroplating. After the electrodes are electroplated, the metal sheet is removed from the cable in order to re-isolate the electrodes.