Laser-Welded Ag Nanowire Mesh Electrode for Bending Durability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current transparent conducting electrodes, such as silver nanowire meshes, face challenges with bending durability due to limited contact area, increased contact resistance, and adhesion issues, while metal meshes offer better conductivity but lack flexibility and have high fabrication costs.
Innovation Solution
A silver nanowire mesh electrode fabricated using selective laser welding with a mesh pattern of intersecting metal lines forming specific angles to enhance bending durability, combined with a polyurethane overcoat layer for improved mechanical stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wet sintering using roll-to-roll process is used to increase nanowire contact area, then conductivity is improved, but polymer substrate deformation occurs due to excessive heat
Solution Approach 1:
The patent replaces thermal sintering (heat-based mechanism) with laser welding (light-based mechanism). The laser welding process uses photothermal effect to locally melt and bond nanowires without generating excessive heat that would deform the polymer substrate, thus resolving the contradiction between improving conductivity through sintering and preventing substrate deformation.
Solution Approach 2:
The patent applies localized laser welding to specific regions where nanowire contacts need to be bonded, rather than applying heat uniformly across the entire substrate. This localized approach ensures that only the necessary areas undergo thermal processing, minimizing overall heat exposure and preventing substrate deformation while still achieving the required contact area improvement.
2Reliability
If high concentration of nanowires is deposited to increase contact area, then conductivity is improved, but optical properties are significantly degraded
Solution Approach 1:
The patent segments the nanowire network into a mesh pattern structure with controlled line widths and spacing. This segmentation allows the conductive pathways to be formed with sufficient contact area while maintaining open spaces between the mesh lines that preserve optical transmittance, thus resolving the contradiction between improving conductivity and maintaining optical properties.
3Reliability
If metal mesh is used to increase contact area, then conductivity and transmittance are improved, but flexibility is reduced and fabrication cost increases
Solution Approach 1:
The patent creates a composite structure combining metal nanowires with a polymer substrate. The nanowire mesh provides the conductive network while the flexible polymer substrate maintains bendability. This composite approach resolves the contradiction between achieving high conductivity through mesh structure and preserving flexibility inherent in polymer-based materials.
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 achieves high bending durability, maintaining excellent electrical conductivity and optical transmittance, with the ability to adjust line width and spacing for optimal performance, suitable for flexible electronic devices.
Implementation Method 1
a laser beam is selectively radiated on a silver nanowire mesh pattern
Implementation Method 2
fabricated using selective laser welding
Data Source
AI summary
According to one aspect of the present invention, a silver nanowire mesh (Ag NW-mesh) electrode and a fabricating method thereof. The Ag NW-mesh electrode includes a flexible substrate; and a mesh pattern layer which is disposed on the flexible substrate and in which a plurality of first meal lines and a plurality of second metal lines are composed of Ag NWs and intersect each other in an orthogonal or diagonal direction to form a grid pattern, wherein the first metal lines and the second metal lines of the mesh pattern layer form an angle of 35 degrees to 55 degrees with respect to a bending direction.