Stretchable Strain Sensor With Periodic Incisions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing strain sensors face challenges in achieving a balance between sensitivity, sensing range, and robustness, often requiring multiple sensors for different strain ranges and being prone to failure under adverse conditions.
Innovation Solution
A soft stretchable resistive strain sensor is developed using a silver nanowire network embedded in a poly(dimethylsiloxane) matrix with periodic mechanical cuts, allowing for crack propagation and blunting, which increases resistance with strain but remains constant beyond a certain point, enhancing sensitivity and range while maintaining robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional strain sensors are used to achieve high sensitivity, then the gauge factor is improved, but the sensing range is limited and robustness deteriorates
Solution Approach 1:
The sensor surface is segmented into multiple regions by introducing periodic incisions that create isolated conductive islands. This segmentation allows cracks to be confined within individual islands rather than propagating across the entire sensor, thereby maintaining sensitivity while improving robustness against complete failure
Solution Approach 2:
The sensor design changes the structural parameters by introducing periodic incisions with specific spacing and depth, transforming the continuous conductive network into a segmented architecture. This parameter change enables the sensor to maintain high gauge factor while extending sensing range and improving robustness through controlled crack propagation
2Reliability
If multiple sensors are used to cover different strain ranges, then the sensing range is improved, but the device complexity increases
Solution Approach 1:
A single sensor design with periodic incisions performs multiple functions: it maintains high sensitivity for small strains through the conductive island structure, extends sensing range to large strains through controlled crack propagation, and provides robustness through the segmented architecture. This universal design eliminates the need for multiple specialized sensors
3Ease of manufacture
If the sensor structure is simplified for ease of manufacture, then the manufacturing process is improved, but the sensitivity and robustness deteriorate
Solution Approach 1:
The periodic incisions are created during the fabrication process using simple techniques such as laser cutting or mechanical scribing, before the sensor is deployed. This preliminary action establishes the crack confinement structure in advance, enabling high sensitivity and robustness to be achieved without complex manufacturing steps
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 sensor achieves a high gauge factor of 290.1 with a sensing range of 22% and reversible range, demonstrating excellent tunability and robustness, suitable for wearable applications and human-machine interfaces.
Implementation Method 1
A soft stretchable resistive strain sensor is developed using a silver nanowire network embedded in a poly(dimethylsiloxane) matrix with periodic mechanical cuts, allowing for crack propagation and blunting, which increases resistance with strain
Data Source
AI summary
An exemplary method for producing a strain sensor using crack propagation includes opening and blunting includes applying conductive nanowires to a substrate to form a conductive nanowire network on the substrate. The method also includes applying an elastomer to the nanowire network to form a composite layer on top of the conductive nanowire network. The method also includes removing the substrate from the conductive nanowire network, wherein removing the substrate at least partially exposes a surface of the conductive nanowire network. The method further includes cutting intervallic incisions in the surface of the conductive nanowire network, wherein the intervallic incisions extend alternatingly and inwardly from one of two opposing edges of the conductive nanowire network.