Low Resistance Sensor Film Using Crosslinked Polymer and Nanotubes
Solution Overview
Problem
Existing sensor films face challenges in maintaining sensitivity to chemical analytes while being stable against temperature fluctuations and mechanical stress, particularly in low resistance applications, where conductive particles often experience phase separation and migration within the polymer matrix.
Innovation Solution
A conductometric sensor film with a crosslinked polymer matrix incorporating conductive axial-geometry particles such as graphene, carbon nanotubes, and carbon black, which are homogeneously distributed to enhance sensitivity and stability, reducing resistance and minimizing temperature cross-sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conductive particles are distributed throughout the polymer film to enhance sensitivity to resistance changes, then sensitivity to chemical analytes is improved, but the particles experience phase separation and migration within the polymer matrix, reducing stability
Solution Approach 1:
The patent uses a composite material system consisting of a polymer matrix combined with conductive particles (such as metal particles, carbon particles, or conductive polymers). This composite structure allows the conductive particles to be distributed throughout the polymer film, enhancing sensitivity to resistance changes while the polymer matrix provides structural stability to prevent phase separation and migration, thereby resolving the contradiction between sensitivity and stability.
Solution Approach 2:
The patent applies local quality by creating regions within the polymer film that have different properties - the polymer matrix provides stability and structural integrity, while the conductive particles provide sensitivity to chemical analytes. The conductive particles are strategically distributed throughout the polymer film, with their local concentration and distribution optimized to enhance sensitivity while maintaining overall stability through the polymer matrix structure.
2Use of energy by moving object
If the sensor film resistance is reduced for low current applications, then energy efficiency is improved, but temperature cross-sensitivity increases, affecting measurement accuracy
Solution Approach 1:
The patent applies parameter changes by carefully selecting and optimizing the resistance range of the sensor film. By reducing the resistance to levels suitable for low current applications (improving energy efficiency), the patent simultaneously adjusts other parameters such as the polymer matrix composition, conductive particle type and concentration, and film thickness to compensate for and minimize temperature cross-sensitivity effects, thereby maintaining measurement accuracy across different temperature conditions.
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 film achieves improved sensitivity to chemical analytes, increased durability, and reduced resistance, enabling robust and accurate detection with long-term performance in low resistance applications.
Implementation Method 1
The polymer absorbs target analytes and this results in a volumetric change of the film, and hence the electrical resistance of the film
Implementation Method 2
A conductometric sensor film for detecting one or more chemical analytes comprises a polymer matrix comprising a crosslinked polymer and a plurality of particles comprising a conductive axial-geometry particle homogeneously distributed within the matrix. In the presence of one or more chemical analytes, the sensor film exhibits a change in resistance.
Implementation Method 3
Many sensor films swell, increasing in volume, while in the presence of the analytes
Implementation Method 4
enhancing the sensitivity to chemical analytes is desirable. Additionally, there are many applications where only a low amount of current is available and require low resistance sensors. There is a need for a low resistance sensor film composition that enhances sensitivity to desired chemical analytes, while further increasing its stability during temperature fluctuations.
Data Source
AI summary
Compositions for sensor films used for detecting chemical analytes within sensors, such as polymer-absorption chemiresistors (i.e., conductometric sensors) are provided. Robust sensor film compositions that have low resistance, high conductivity, and greater temperature stability and sensitivity to chemical analytes are provided, as well as methods of making these sensor films. Such sensor film compositions include a matrix having a polymer resin and a plurality of conductive particles comprising an axial-geometry conductive particle. Exemplary axial-geometry conductive particles comprise graphene, such as a carbon nanotube. Blends of conductive particles are also contemplated, including blends of axial-geometry conductive particles, such as carbon nanotubes, and carbon black.