Load Sensor With Variable-Pore Dielectric for Linear Capacitance Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing load sensors with linearly shaped conductive members exhibit a curved wave relationship between load and capacitance, complicating the process of load detection.

Innovation Solution

A load sensor design featuring a first and second base member with conductive elastic bodies and a dielectric body that adjusts the contact area to achieve a linear change in capacitance with load, using a dielectric body with varying pore density or surface roughness to linearize the capacitance-load relationship.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a linearly shaped electrically-conductive member is used, then the structure is simple, but the relationship between load and capacitance becomes curved wave shape complicating detection

Engineering Contradiction:

ImprovestructureVSAvoidload detection process

Core Design Contradiction:

Device complexityVSDifficulty of detecting and measuring

Solution Approach 1:

The dielectric body is designed with non-uniform pore density distribution, where the density of pores varies in the contact surface direction. This local variation in pore density creates a corresponding variation in dielectric constant across different regions, which compensates for the non-linear contact area changes and linearizes the overall capacitance-load relationship.

Inventive Principle:

Principle #3Local quality

2Measurement precision

If the contact area increases with load, then capacitance detection is enabled, but the relationship becomes curved wave shape requiring complex processing

Engineering Contradiction:

Improvecapacitance detectionVSAvoiddetection process

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The dielectric constant of the dielectric body is made to vary spatially by controlling the pore density distribution. This parameter change in the dielectric property compensates for the non-linear mechanical contact area changes, transforming the curved wave relationship into a linear relationship between capacitance and load.

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

Enables simpler and more accurate load detection by establishing a linear correlation between capacitance and load, facilitating straightforward calculation.

Implementation Method 1

capacitance between the electrically-conductive elastic body and the electrically-conductive member

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

a dielectric body disposed between the electrically-conductive elastic body and the electrically-conductive member

Methodology Applied

Scientific EffectDielectric: Dielectric

Data Source

PatentUS12460977B2Load sensor

Publication Date: 2025.11.04 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A load sensor includes: a first base member and a second base member disposed so as to face each other; an electrically-conductive elastic body disposed on an opposing face of the first base member; an electrically-conductive member disposed between the second base member and the electrically-conductive elastic body; a dielectric body disposed between the electrically-conductive elastic body and the electrically-conductive member; and a component configured to change a contact area of the dielectric body in association with increase in a load, such that a form of change in capacitance between the electrically-conductive elastic body and the electrically-conductive member associated with change in the load becomes close to that of a straight line.