Elastic Protrusion Pressure Sensor Linearity via Segmented Capacitance

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Solution Overview

Problem

Pressure sensing elements face challenges in maintaining linearity across low-load and high-load applications due to the increase in load necessary for deformation of elastic electrodes, requiring complex structures for control, which complicates their design.

Innovation Solution

A pressure sensing element with a simple structure achieves high linearity by incorporating two capacitances with different characteristics, utilizing a first capacitor with a contact area between an elastic protrusion and a dielectric, and a second capacitor with a non-contact area, where the elastic protrusion and dielectric deform in response to load, allowing for controlled sensitivity adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conventional pressure sensing element uses a single capacitance structure, then the device complexity is low, but the linearity across different load ranges deteriorates

Engineering Contradiction:
ImprovelinearityVSAvoidstructure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The pressure sensing element is segmented into two distinct capacitance structures: a first capacitance with a first electrode and first dielectric, and a second capacitance with a second electrode and second dielectric. Each capacitance structure has different geometric characteristics (different areas and/or thicknesses), allowing them to contribute differently to the overall capacitance change under load. This segmentation enables independent optimization of each capacitance's response characteristics, achieving high linearity across both low-load and high-load sections without requiring a complex single-structure design.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If the elastic electrode deforms under load, then the sensitivity of load detection is improved, but the load necessary for deformation increases, deteriorating the linearity control

Engineering Contradiction:
Improveload detection sensitivityVSAvoidlinearity control complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention changes the parameters of the capacitance structures by providing at least two capacitances with different geometric parameters (different electrode areas, different dielectric thicknesses). This allows each capacitance to have different sensitivity characteristics to load deformation. The first capacitance can be optimized for low-load detection while the second capacitance is optimized for high-load detection, and their combined effect achieves high linearity across the full load range without requiring complex control mechanisms.

Inventive Principle:
Principle #35Parameter changes

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

This configuration enables high linearity in capacitance change characteristics across both low-load and high-load applications without the need for complex structures, improving sensitivity control and maintaining accurate load detection.

Implementation Method 1

a pressure sensing element having a capacitance... the pressure sensing element has a capacitance which includes a first capacitance and a second capacitance

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

a first electrode including at least one protrusion having elasticity... the at least one protrusion and the first dielectric are both deformed when the load is applied

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3037797B1Pressure sensing element comprising an electrode including a protrusion having elasticity
Publication Date: 2018.02.07 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3037797B1 patent drawingFigure 1
  • EP3037797B1 patent drawingFigure 2A~2C
  • EP3037797B1 patent drawingFigure 3

AI summary

A pressure sensing element of an aspect of the present disclosure includes a first electrode including at least one protrusion having elasticity; a second electrode facing the at least one protrusion; and a dielectric disposed between the first electrode and the second electrode and including a first dielectric and a second dielectric. The first dielectric is disposed between a top of the at least one protrusion and the second electrode, and is in contact with each of the top of the at least one protrusion and the second electrode. The second dielectric is disposed between a first portion of the first electrode, the first portion not including the at least one protrusion, and the first dielectric.