Flat Compressible Volume Capacitive Sensor for Pressure Distribution
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Solution Overview
Problem
Current pressure and deformation sensors are inadequate for measuring pressure distributions on flexible, deformable surfaces due to low sensitivity and high complexity, making them unsuitable for broad applications such as seat occupancy detection, decubitus prevention, and diabetic foot pressure monitoring.
Innovation Solution
A flat, capacitive, volume-compressible sensor with flexible outer surfaces that increases capacitance upon pressure application, featuring compressible cavities and elastomeric materials for enhanced sensitivity and adaptability, allowing for precise measurement of pressure distributions on deformable surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional pressure sensors are used to measure pressure distributions on flexible surfaces, then measurement capability is provided, but sensitivity is insufficient and device complexity increases
Solution Approach 1:
The patent changes the physical parameters of the sensor by using compressible cavities that deform under pressure, altering the capacitance value. This allows high sensitivity pressure measurement through simple capacitance detection without complex sensor arrays, resolving the contradiction between measurement precision and device complexity
Solution Approach 2:
The patent replaces complex mechanical pressure sensor systems with a simplified capacitive sensing system. Instead of using multiple mechanical pressure sensors, a single capacitive sensor with compressible cavities detects pressure through electrical capacitance changes, reducing device complexity while maintaining measurement precision
2Measurement precision
If multiple sensors are used to cover large measurement areas, then spatial resolution is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent segments the sensor into multiple compressible cavities distributed across the measurement area. Each cavity acts as an independent sensing element, providing spatial resolution through localized deformation detection while using a single integrated sensor structure rather than multiple separate sensors
Solution Approach 2:
The patent transitions from measuring pressure in one dimension with multiple sensors to measuring pressure distribution across two dimensions using a single planar sensor with distributed cavities. The cavities are arranged in a pattern that enables spatial mapping of pressure distributions without requiring multiple stacked or sequential sensors
3Ease of manufacture
If rigid sensor structures are used, then manufacturing is simplified, but adaptability to flexible surfaces is reduced
Solution Approach 1:
The patent uses a flexible substrate that can conform to deformable surfaces such as human skin. The compressible cavities are formed within this flexible structure, allowing the sensor to adapt to curved and moving surfaces while maintaining a relatively simple manufacturing process using flexible circuit board technology
Solution Approach 2:
The patent employs composite material structures combining flexible substrates, conductive materials for electrodes, and compressible cavity structures. This composite approach enables both flexibility for adaptability and structured design for ease of manufacture, resolving the contradiction between structural simplicity and surface adaptability
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 pressure sensitivity and spatial resolution, enabling effective measurement of pressure distributions on flexible surfaces, such as seats and beds, with simple and cost-effective production, suitable for various applications including airbag control, decubitus prevention, and diabetic foot monitoring.
Implementation Method 1
the electrical capacitance is measurably increased when pressure is applied to the sensor
Implementation Method 2
flat, capacitive, volume-compressible sensor that is flexible on at least one of its outer surface sides
Data Source
Figure 1a~2b
Figure 3a~4c
Figure 5a~5b
AI summary
The sensor has a planar elastomer film (6) that is formed between electrodes for measuring electric capacitance. The elastomer film is arranged above or below in flexible or rigid surface. A cavity (5) is formed between elastomer film and flexible or rigid surface in an unstressed state of main portion. The outer surface side of main portion is deformed, such that distance between electrodes is reduced by reducing the volume of the cavity to increase measuring of electric capacitance. An independent claim is included for a receptacle.