Piezoelectric Braid Structure for Signal Extraction and Durability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing piezoelectric elements, such as those using polylactic acid fibers or carbon fibers, struggle to generate sufficient electrical output from shearing stress and are prone to degradation, making them unsuitable for applications requiring repeated durability and precise shape information measurement.
Innovation Solution
A piezoelectric structure comprising a braid of conductive fibers coated with piezoelectric polymers, featuring bent sections and knots, which allows for increased electrical signal extraction from small deformations and improved durability through the use of polylactic acid fibers with high optical purity and uniaxial orientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a piezoelectric sheet comprising polylactic acid is used to detect pressure and positional information, then the sheet can simultaneously detect both pressure and positional information with a single element, but sufficient electrical output cannot be obtained by tension or compression stress alone
Solution Approach 1:
The invention uses a composite structure combining piezoelectric polymer fibers (polylactic acid) with conductive fibers. The piezoelectric polymer provides detection capability while the conductive fiber enhances electrical output through its piezoelectric effect under shearing stress, resolving the contradiction between versatility and power output.
Solution Approach 2:
The invention changes the structural parameters by creating a braided composite where piezoelectric polymer fibers are oriented at specific angles (15-75 degrees) relative to the conductive fiber axis. This angular orientation optimizes the piezoelectric response to shearing stress, enabling sufficient electrical output while maintaining detection versatility.
2Power
If piezoelectric fibers are used to generate electrical output through shearing stress by rubbing, then electrical output can be obtained, but the fibers are prone to breaking and degradation
Solution Approach 1:
The conductive fiber serves as a structural reinforcement within the composite. It provides mechanical strength and resistance to breaking while the piezoelectric polymer fibers generate electrical output through shearing stress. This composite structure resolves the contradiction between power generation and durability.
Solution Approach 2:
The conductive fiber acts as a protective core that cushions and protects the piezoelectric polymer fibers from direct mechanical stress and breaking. This beforehand protection ensures long-term durability while maintaining the ability to generate electrical output through controlled shearing stress.
3Ease of manufacture
If a simple covered fiber structure is used, then the structure is simple and easy to manufacture, but insufficient electrical signal is extracted from small deformations
Solution Approach 1:
The braided composite structure of piezoelectric polymer fibers and conductive fibers provides enhanced electrical signal extraction from small deformations compared to simple covered fiber structures. The multiple fibers arranged in a braid configuration create cumulative piezoelectric effect, improving measurement precision while remaining manufacturable.
Solution Approach 2:
The piezoelectric element is segmented into multiple piezoelectric polymer fibers braided around a conductive core. This segmentation allows the cumulative effect of multiple fibers to generate sufficient electrical signal from small deformations, improving measurement precision while maintaining ease of manufacture through standard braiding techniques.
4Power
If polylactic acid fibers with high optical purity and uniaxial orientation are used, then electrical output is improved, but manufacturing complexity increases
Solution Approach 1:
The invention specifies precise parameter ranges for the piezoelectric polymer fibers, including optical purity of 99% or higher and uniaxial orientation with crystal orientation factor of 0.8 or higher. These controlled parameter changes ensure high electrical output while the parameters are achievable through established polymer fiber manufacturing techniques, balancing performance with manufacturability.
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 proposed structure enables the extraction of larger electrical signals from small deformations, enhances durability, and maintains design aesthetic quality, making it suitable for applications requiring high design properties and precise stress detection.
Implementation Method 1
A piezoelectric polymer, for example, polylactic acid, is used as the piezoelectric fiber A, and the surface of the conductive fiber B is covered with the piezoelectric fiber A in a braided form
Data Source
AI summary
Provided is a piezoelectric structure including a braid composed of a conductive fiber and piezoelectric fibers, the braid being a covered fiber having the conductive fiber as the core and the piezoelectric fibers covering the periphery of the conductive fiber, wherein the covered fiber has at least one bent section, and when the piezoelectric structure is placed on a horizontal surface, the height from the horizontal surface to the uppermost section of the piezoelectric structure is greater than the diameter of the covered fiber.