Transparent Flexible Circuits Using Graphene and Copper Traces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing transparent conductive films face challenges in balancing light transmission and electrical conductivity, particularly with Indium Tin Oxide (ITO) being costly due to resource scarcity, and there is a need for high-density, flexible, and biocompatible sensor substrates.
Innovation Solution
A transparent flexible substrate structure using cyclo-olefin polymer and monolayer or bilayer graphene circuitry with copper traces and dielectric bonding films, enabling ultra-high circuit density and biocompatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Indium Tin Oxide (ITO) is used as transparent conductive film material, then electrical conductivity is improved, but manufacturing cost increases due to scarcity of Indium resources
Solution Approach 1:
The patent replaces expensive ITO with graphene, a cheaper alternative material that can be deposited as thin films. Graphene provides comparable electrical conductivity at lower cost, addressing the manufacturing cost issue while maintaining the required electrical performance for transparent conductive applications
Solution Approach 2:
The patent employs composite structures combining graphene with other materials such as silver nanowires or metal oxides to achieve optimal balance between transparency and electrical conductivity. This composite approach allows tuning of electrical properties to match or exceed ITO performance while reducing dependence on scarce indium resources
2Reliability
If Indium Tin Oxide (ITO) is used as transparent conductive film material, then electrical conductivity is improved, but material cost increases due to scarcity of Indium resources
Solution Approach 1:
The patent substitutes expensive ITO with graphene, which is derived from abundant carbon sources. This replacement dramatically reduces material cost while maintaining electrical conductivity, directly addressing the material cost issue caused by indium scarcity
Solution Approach 2:
The patent modifies the electrical conductivity parameters by using graphene's unique electronic properties. Graphene's high carrier mobility and conductivity allow achieving the same electrical performance as ITO with different material parameters, thereby reducing material cost
3Illumination intensity
If transparent conductive film is made thinner to improve light transmission, then transparency is improved, but electrical conductivity deteriorates
Solution Approach 1:
The patent exploits graphene's exceptional electrical properties, which allow achieving high conductivity at extremely thin film thicknesses. This enables maintaining electrical conductivity even when the film is made ultra-thin for optimal light transmission, resolving the trade-off between transparency and conductivity
Solution Approach 2:
The patent uses composite structures such as graphene-silver nanowire hybrids or graphene-metal oxide composites to enhance electrical conductivity in ultra-thin configurations. These composites provide synergistic effects where graphene's high mobility compensates for reduced thickness, maintaining conductivity while maximizing light transmission
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 provides optically transparent, flexible substrates with ultra-high circuit density and mechanical protection, suitable for biocompatible sensors and communication devices, offering excellent electrical, mechanical, and optical properties.
Implementation Method 1
Graphene as a single sheet transparent conducting material is a promising material for TCF. Graphene offers various potential advantages over ITO film including density, robustness, flexibility, chemical stability and cost.
Implementation Method 2
an optically transparent cyclo-olefin polymer flexible substrate
Implementation Method 3
an optically transparent dielectric bonding film on the cyclo-olefin polymer surface
Implementation Method 4
copper traces on the bonding film and electrically connected to the graphene circuitry at edges of a transparent area
Data Source
AI summary
A transparent flexible substrate structure comprises an optically transparent cyclo-olefin polymer flexible substrate, an optically transparent dielectric bonding film on the cyclo-olefin polymer surface, a monolayer graphene circuitry on the bonding film, copper traces on the bonding film and electrically connected to the graphene circuitry at edges of a transparent area, and a layer of transparent permanent resist on top of the graphene circuitry and portions of the copper traces.