Conductive Silicone Elastomer Ink for Stretchable Printed Electrodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrically conductive printing inks for silicone elastomers often require solvents to achieve printability, which increases costs and environmental concerns, and struggle with maintaining conductivity when stretched, especially for applications like dielectric elastomer sensors and actuators.
Innovation Solution
A solvent-free, electrically conductive silicone elastomer composition using conductivity soot and multi-walled carbon nanotubes (MWCNTs) with a high aspect ratio, filtered through a metal fabric with a mesh size of 200 µm or smaller, to create a smooth, particle-free surface and maintain electrical properties during stretching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conductive carbon particles are used as fillers in silicone elastomer printing ink, then electrical conductivity is improved, but viscosity increases significantly making printing difficult
Solution Approach 1:
The patent extracts and removes the solvent component from traditional conductive printing ink formulations. By creating a solvent-free silicone elastomer composition, the invention eliminates the need to balance solvent content against particle concentration, allowing high conductive filler loading without viscosity-related printing issues while maintaining printability through the elastomer's inherent flow properties
Solution Approach 2:
The patent creates a composite material system combining silicone elastomer base resin with high aspect ratio conductive fillers (carbon nanotubes and/or graphite flakes). This composite approach allows the elastomer matrix to provide both the printing medium functionality and the flexible substrate properties, while the high aspect ratio fillers provide efficient conductive networks at lower concentrations compared to spherical particles
2Ease of operation
If solvents are used in silicone printing inks to reduce viscosity and improve printability, then ease of application is improved, but occupational safety and environmental protection costs increase
Solution Approach 1:
The patent extracts and removes the solvent component from traditional conductive printing ink formulations. By creating a solvent-free silicone elastomer composition, the invention eliminates the need to balance solvent content against particle concentration, allowing high conductive filler loading without viscosity-related printing issues while maintaining printability through the elastomer's inherent flow properties
Solution Approach 2:
The silicone elastomer base resin itself serves dual functions: as the printing medium providing appropriate viscosity and flow characteristics, and as the flexible substrate material. This self-service approach eliminates the need for separate solvent and substrate materials, reducing environmental impact and simplifying the overall system
3Ease of manufacture
If spherical conductive particles are used in elastomer, then ease of mixing is improved, but conductive network formation deteriorates when stretched
Solution Approach 1:
The patent changes the geometric parameter of the conductive fillers from spherical to high aspect ratio (carbon nanotubes with length-to-diameter ratio >10 or graphite flakes). This parameter change transforms the filler morphology to enable conductive network formation that remains stable under stretching, as the elongated shapes can bridge gaps and maintain connectivity even when the elastomer matrix deforms
Solution Approach 2:
The patent creates a composite material system combining silicone elastomer base resin with high aspect ratio conductive fillers (carbon nanotubes and/or graphite flakes). This composite approach allows the elastomer matrix to provide both the printing medium functionality and the flexible substrate properties, while the high aspect ratio fillers provide efficient conductive networks at lower concentrations compared to spherical particles
4Manufacturing precision
If laser transfer printing is used for applying conductive layers, then printing precision is improved, but the process is limited to low-viscosity inks and metals
Solution Approach 1:
The patent changes the viscosity parameter of the printing ink by formulating a solvent-free silicone elastomer composition with appropriate filler content. This parameter adjustment brings the viscosity into the optimal range for laser transfer printing processes, enabling the use of this precise printing method with high-viscosity conductive elastomer materials that were previously incompatible
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 the production of electrodes with a smooth, particle-free surface and consistent electrical resistance, suitable for stretchable applications like dielectric elastomer sensors and actuators, without the need for solvents, thus reducing environmental impact and operational costs.
Implementation Method 1
The high aspect ratio of the conductive particles ensures that, in contrast to spherical particles, the conductive particles can form a conductive network throughout the entire system with smaller filler quantities; this conductive network persists even when the elastomer is stretched. This ensures good electron conduction even when the elastomer is stretched.
Implementation Method 2
filtered through a metal fabric with a mesh size of 200 µm or smaller, to create a smooth, particle-free surface
Data Source
AI summary
The invention relates to an electrically conductive, cross-linking silicone elastomer composition as and electrically conductive printing ink in contactless printing processes for producing electrodes for sensors, actuators or EAP layer systems.