Flexible Device Adhesive Layer with Region-Specific Viscoelasticity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing flexible devices face issues with pressure-sensitive adhesive layers due to varying forces applied during folding or rolling, leading to defects like lifting, peeling, and bubble generation, as conventional methods struggle to effectively differentiate physical properties across different regions of the adhesive layer.
Innovation Solution
A pressure-sensitive adhesive layer with distinct first and second regions having different physical properties, such as elastic modulus and creep strain rate, is developed, allowing for controlled differences in properties to enhance deformation handling and stability while minimizing defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a pressure-sensitive adhesive layer with uniform physical properties is applied across all parts, then manufacturing is simple, but defects like lifting, peeling, and bubble generation occur in folding or rolling parts
Solution Approach 1:
The adhesive layer is designed with different physical properties in different regions: the first region (folding/rolling part) has lower elastic modulus and higher creep strain rate to accommodate deformation, while the second region (other parts) has higher elastic modulus and lower creep strain rate for stability. This local differentiation eliminates defects like lifting and peeling in folding areas while maintaining manufacturing feasibility through a single-layer structure.
Solution Approach 2:
The patent changes physical parameters (elastic modulus and creep strain rate) of the adhesive material across different regions of the same layer. By controlling the ratio of creep strain rate to elastic modulus differently in the first and second regions, the adhesive can simultaneously handle deformation in folding parts and maintain stability in other parts, resolving the contradiction between uniform manufacturing and region-specific performance.
2Manufacturing precision
If the pressure-sensitive adhesive layer is made with high elastic modulus and low creep strain rate for cuttability and workability, then manufacturing precision improves, but the adhesive cannot accommodate deformation forces in folding or rolling parts
Solution Approach 1:
The adhesive layer is divided into two regions with different mechanical properties. The second region (non-folding parts) has high elastic modulus and low creep strain rate for good cuttability and workability during manufacturing. The first region (folding/rolling parts) has lower elastic modulus and higher creep strain rate to accommodate deformation forces, thus resolving the contradiction between manufacturing precision and deformation adaptability.
Solution Approach 2:
The adhesive layer is segmented into a first region and a second region with distinct physical properties. This segmentation allows each region to be optimized for its specific function: the second region for manufacturing operations requiring high stiffness, and the first region for deformation accommodation during folding or rolling, eliminating the need to compromise overall performance.
3Adaptability or versatility
If the pressure-sensitive adhesive layer is made with low elastic modulus and high creep strain rate for deformation accommodation, then adaptability to folding or rolling improves, but cuttability and workability deteriorate
Solution Approach 1:
The adhesive layer is designed with spatially varying properties: the first region (folding/rolling part) has low elastic modulus and high creep strain rate to accommodate deformation forces effectively. The second region (other parts) has high elastic modulus and low creep strain rate to ensure good cuttability and workability during manufacturing. This local quality differentiation resolves the contradiction between deformation adaptability and manufacturing precision.
4Adaptability or versatility
If electromagnetic waves are used to create physical property differences in the adhesive layer, then region-specific properties are achieved, but the difference in physical properties between regions cannot be greatly increased
Solution Approach 1:
The patent utilizes electromagnetic wave irradiation to induce cross-linking in the pressure-sensitive adhesive layer, creating regions with different cross-linking densities. By controlling the irradiance level and irradiation conditions, the patent achieves significant differences in physical properties (elastic modulus and creep strain rate) between the first and second regions. This approach overcomes the limitation of conventional methods by enabling greater physical property deviation through optimized cross-linking parameters.
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 effectively relieves stress during folding or rolling, maintains stability, and prevents defects like lifting and peeling, ensuring consistent performance across temperature and usage conditions.
Implementation Method 1
A pressure-sensitive adhesive layer with distinct first and second regions having different physical properties, such as elastic modulus and creep strain rate, is developed, allowing for controlled differences in properties to enhance deformation handling and stability
Implementation Method 2
The solution effectively relieves stress during folding or rolling, maintains stability, and prevents defects like lifting and peeling, ensuring consistent performance across temperature and usage conditions
Data Source
AI summary
The present application may provide a flexible device comprising a pressure-sensitive adhesive layer comprising at least first and second regions having different physical properties, wherein the difference in physical properties, such as an elastic modulus or creep strain rate, which are advantageous as the difference in physical properties between the regions increases, is maintained relatively large for each region, and the difference in physical properties, such as a peel force or recovery rate, which are advantageous as the difference in physical properties between the regions decreases, is maintained relatively small for each region.