Auxetic Zipper Teeth for Durable Secure Interlocking
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Solution Overview
Problem
Conventional fasteners and closure devices, such as zippers, bottle caps, and rivets, often lack the necessary structural properties to efficiently and securely fasten objects due to limitations in material properties like Poisson's ratio, leading to issues with durability and long-term performance.
Innovation Solution
The use of negative Poisson's ratio (NPR) materials, either alone or in composite form with positive Poisson's ratio (PPR) materials, in the construction of fasteners, enabling efficient fastening and secure connections by incorporating NPR foam materials, such as metal, polymer, or ceramic foams, and PPR materials, which provide enhanced strength, durability, and deformation characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional positive Poisson's ratio materials are used in fasteners, then the fasteners can be manufactured with standard materials, but the fasteners lack the necessary structural properties to efficiently and securely fasten objects
Solution Approach 1:
The patent employs composite materials combining positive Poisson's ratio (PPR) materials and negative Poisson's ratio (NPR) materials to create fasteners with superior mechanical properties. The PPR material provides structural integrity and ease of manufacturing, while the NPR material enhances deformation characteristics and fastening security through its auxetic behavior of expanding laterally when compressed
Solution Approach 2:
The patent changes the Poisson's ratio parameter of the fastener materials by incorporating NPR materials with negative Poisson's ratio values. This parameter change fundamentally alters the deformation behavior of the fastener components, enabling them to expand in the lateral direction during compression, which improves interlocking and fastening security
2Reliability
If NPR materials are used to enhance fastening ability, then the fastening security improves, but the manufacturing process becomes more complex
Solution Approach 1:
By creating composite fasteners that integrate both PPR and NPR materials, the patent achieves enhanced fastening durability through the synergistic effects of the two material types. The PPR material maintains manufacturability and structural stability, while the NPR material provides superior deformation characteristics, together resolving the contradiction between performance enhancement and manufacturing complexity
3Reliability
If conventional materials are used in zippers, then the zipper can be manufactured easily, but the teeth lack the ability to maintain tight interlocking over time
Solution Approach 1:
The patent applies composite materials to zipper teeth, combining PPR and NPR materials to achieve tight and durable interlocking. The NPR material's auxetic property causes the teeth to expand laterally when compressed during zipping, creating a tighter fit and more stable interlocking that maintains performance over time, while the PPR material ensures 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 integration of NPR materials into fasteners enhances their ability to securely fasten objects, maintains performance over time, and offers improved strength and durability, ensuring effective interlocking even as they age.
Implementation Method 1
at least some of the zipper teeth comprise a negative Poisson's ratio (NPR) foam material having a Poisson's ratio of between 0 and −1
Implementation Method 2
Forming the zipper teeth from an NPR foam material comprises heating and compressing a positive Poisson's ratio (PPR) foam material to form the NPR foam material
Implementation Method 3
a smooth cylindrical shaft, the shaft configured to expand in diameter when deformed; wherein the shaft comprises a negative Poisson's ratio (NPR) material
Data Source
AI summary
The disclosure describes a zipper including two rows of zipper teeth, in which at least some of the zipper teeth include a negative Poisson's ratio (NPR) foam material having a Poisson's ratio of between 0 and −1, and a slider movably attached to one of the rows of the zipper teeth and configured to connect the two rows of zipper teeth when the slider is moved in a first direction and to disconnect the two rows of zipper teeth when the slider is moved in an opposite direction.