Conductive Fluororesin Earth Ring for Static Dissipation in Pressure Sensors
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Solution Overview
Problem
Conventional pressure sensors face defects due to static electricity accumulation on the housing and pressure-sensitive portions, leading to damage when discharged to aluminum foil, causing issues with fluid contact and sensor malfunction.
Innovation Solution
A pressure detection device with a contact portion made of conductive fluororesin material, maintained at ground potential, is used to dissipate static electricity, preventing accumulation on the pressure detection and flow channel surfaces, and an annular seal member is employed to ensure fluid containment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If aluminum foil is attached to the pressure-sensitive portion to discharge static electricity, then static electricity on the pressure-sensitive portion is removed, but static electricity on the housing can still discharge to the sensor element causing damage
Solution Approach 1:
A contact portion made of conductive fluororesin material is introduced as an intermediary between the housing and the pressure-sensitive portion. This contact portion serves as a mediator that safely conducts static electricity from the housing to ground potential without allowing it to discharge to the sensor element, thus protecting the sensor while maintaining static discharge capability
Solution Approach 2:
The contact portion is formed using composite material consisting of fluororesin material combined with conductive material (such as carbon black or graphite). This composite structure provides both the chemical resistance of fluororesin and the electrical conductivity needed to dissipate static electricity, preventing accumulation on both the housing and pressure-sensitive portion
2Reliability
If fluorine-contained resin is used for the housing and pressure-sensitive portion to achieve chemical resistance, then chemical resistance is improved, but static electricity accumulation occurs due to friction with liquid
Solution Approach 1:
Different materials are applied to different parts of the device: fluorine-contained resin is used for the housing and pressure-sensitive portion to provide chemical resistance, while conductive fluororesin material is specifically used for the contact portion to provide static electricity dissipation. This local differentiation allows each component to have the optimal material properties for its specific function
Solution Approach 2:
The electrical conductivity parameter of the contact portion is changed by incorporating conductive material into the fluororesin. This parameter change allows the contact portion to actively dissipate static electricity while the rest of the housing maintains its insulating properties for chemical resistance
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 solution effectively prevents static electricity-induced defects, ensuring reliable pressure detection and fluid containment by maintaining the contact portion at ground potential and using a conductive fluororesin material with carbon nanotubes for conductivity, while minimizing fluid contamination.
Implementation Method 1
The contact portion is formed of a conductive fluororesin material including a fluororesin material and a conductive material dispersed in the fluororesin material, and is maintained at a ground potential
Implementation Method 2
static electricity is likely to be accumulated on the housing and the pressure-sensitive portion due to a friction with the liquid
Data Source
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AI summary
Provided is a pressure detection device 100 including: a pressure sensor 11 including a pressure detection surface for detecting a pressure of a fluid; and a flow channel unit 20 having a flow channel 21a formed therein to guide the fluid to the pressure detection surface. The flow channel unit 20 includes a flow channel body 21 having the flow channel 21a formed therein, and an earth ring 22 disposed in contact with the pressure sensor 11. The earth ring 22 is formed of a conductive fluororesin material including a fluororesin material and a conductive material in which the fluororesin material is dispersed, and is maintained at a ground potential.