Galvanic Dryness Sensor with Hydrophobic Coating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional dryness/wetness responsive sensors face limitations in sensitivity, stability, and functionality, particularly in detecting fine liquid droplets and operating under conditions of dew condensation, with issues such as breakdown in humid environments, high temperature dependency, and inability to measure droplet size.
Innovation Solution
A small-sized dryness/wetness responsive sensor is developed with thin wires of different metals on an insulating substrate, where the surface state between the wires is hydrophilic or hydrophobic, and an insulating film is formed to enhance sensitivity and detection capabilities, allowing for droplet size measurement and operation in dew condensation conditions without external power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a polymer, ceramics, or other material is used as the sensor element in an electric resistance type humidity sensor, then the structure is simple and mass production is achieved, but the sensor element breaks down when wet with water and cannot be used under dew condensation conditions
Solution Approach 1:
The patent introduces a hydrophobic coating layer as an intermediary between the sensor element and the liquid water environment. This coating acts as a protective mediator that prevents direct contact between water and the sensor element, thereby maintaining reliability in humid conditions while preserving the simple structure and mass production capability of electric resistance type sensors
2Adaptability or versatility
If the measurement humidity range is extended to low humidity environment of 10% RH or less and high humidity environment of over 90% RH, then the sensor can operate under dew condensation conditions, but the sensor element breaks down
Solution Approach 1:
The hydrophobic coating serves as a protective intermediary that enables the sensor to operate across the full humidity range (0-100% RH) including dew condensation conditions. The coating prevents water penetration to the sensor element while allowing humidity sensing, thus extending adaptability without compromising reliability
3Measurement precision
If conventional humidity sensor structures are used, then the sensor can detect humidity, but the sensor cannot detect the size of water droplets attached to the surface
Solution Approach 1:
The patent applies a multi-functional coating that simultaneously provides hydrophobic protection for accurate humidity sensing and incorporates droplet size detection capability. The coating structure enables both traditional humidity measurement and additional droplet characterization, achieving universality without sacrificing measurement precision
4Measurement precision
If a polymer membrane is used in an electrostatic capacitance type humidity sensor, then the response speed is faster and precision is higher, but the production cost is higher than electric resistance type
Solution Approach 1:
The patent employs a cost-effective hydrophobic coating material that can be applied through simple processes to maintain low production costs. The coating uses economical materials and application methods that preserve the manufacturing advantages of electric resistance type sensors while achieving the precision and response characteristics of more expensive sensor types
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 high sensitivity and quick response without the need for external power, functioning effectively in various humidity levels and enabling accurate detection of water droplets, improving detection accuracy and sensitivity.
Implementation Method 1
a dryness/wetness responsive sensor based on galvanic action has been developed... detecting a current flowing between the metal wirings when the minute spacing is touched with a water droplet
Implementation Method 2
a surface state of a part between the thin wire of the first metal and the thin wire of the second metal is hydrophilic or hydrophobic
Data Source
AI summary
The present invention is to provide a small-sized dryness/wetness responsive sensor that detects a galvanic current with a high sensitivity as a principle of operation. According to one embodiment of the present invention, a dryness/wetness responsive sensor comprises a thin wire made of a first metal and a thin wire made of a second metal, the second metal is different from the first metal, the thin wire of the first metal and the thin wire of the second metal are disposed in juxtaposition with each other on an insulating substrate, and a surface state of a part between the thin wire of the first metal and the thin wire of the second metal is hydrophilic or hydrophobic.