Core-Shell Fiber Strain Sensor for Composite Structure Integrity
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Solution Overview
Problem
Existing strain sensors for composite structures face challenges in maintaining mechanical integrity, achieving low noise levels, and ensuring high linearity for accurate strain sensing, particularly when embedded within composite materials.
Innovation Solution
A core-shell structured fiber-type strain sensor is developed, featuring a fibrous support core with a multilayered shell comprising a first elastomer, a sandwich-structured conductive layer, and a second elastomer, which senses strain based on resistance changes, utilizing conductive particles like carbon nanotubes and varying their weight percentage for improved mechanical properties and signal linearity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a strain sensor is embedded in composite structures, then strain sensing capability is achieved, but mechanical integrity and strength are compromised
Solution Approach 1:
The sensor uses a flexible polymer coating layer containing conductive particles formed on a thin substrate. This thin-film structure allows the sensor to be embedded within composite laminates without significantly compromising the mechanical strength and integrity of the composite structure, while still providing effective strain sensing capability through the conductive particle network that responds to deformation.
Solution Approach 2:
The sensor employs a composite structure combining a polymer matrix with dispersed conductive particles (such as carbon black or metal particles). This composite material approach enables the sensor to achieve both mechanical compatibility with the host composite structure and sufficient electrical conductivity for strain measurement, resolving the contradiction between strength and sensing capability.
2Measurement precision
If conductive particles are used for strain sensing, then sensitivity is improved, but noise level increases
Solution Approach 1:
The sensor optimizes the concentration, size distribution, and type of conductive particles within the polymer matrix to achieve an optimal balance between sensitivity and noise. By carefully controlling these parameters, the sensor achieves sufficient sensitivity for strain detection while minimizing electrical noise and signal instability that would otherwise occur with suboptimal particle configurations.
Solution Approach 2:
The polymer matrix acts as an intermediary medium that distributes and stabilizes the conductive particles. This intermediary structure prevents particle aggregation and provides a stable matrix that reduces noise while maintaining the sensitivity needed for accurate strain sensing, effectively mediating between the conductive particles and the external environment.
3Ease of manufacture
If a simple sensor structure is used, then ease of manufacture is improved, but linearity of measurement signals deteriorates
Solution Approach 1:
The conductive particles are pre-dispersed and uniformly distributed within the polymer matrix before the coating is applied to the substrate. This preliminary dispersion action ensures that the conductive network is formed with appropriate uniformity and structure, which maintains signal linearity while allowing the overall manufacturing process to remain simple and compatible with existing coating techniques.
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 configuration enhances the sensor's strength, stiffness, and noise reduction, enabling stable and reliable strain measurement within composite structures while maintaining structural integrity and reducing defects, with potential for broader applications and lower manufacturing costs.
Implementation Method 1
the sensor senses the strain of a structure including the sensor based on the change in resistance of the conductive layer
Data Source
AI summary
The core-shell structured fiber-type strain sensor of the present disclosure, which includes a fibrous support forming a core and a multilayered shell layer formed on the fibrous support, exhibits improved strength and stiffness due to the core fiber, exhibits improved noise level due to an elastomer layer and allows manufacturing of a fiber-type sensor with improved linearity of measurement signals due to a sandwich-structured conductive layer, is advantageous in that stable strain measurement is possible without acting as a defect in a composite structure.