Resonant Contactless Electric-Field Sensing for Higher DC Sensitivity

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional DC electric-field sensors face issues such as low sensitivity, limited measurement range, and malfunctions due to foreign matter, particularly in semiconductor-based electrometers and rotatable electrode type electrometers.

Innovation Solution

A contactless DC electric-field sensor utilizing a variable capacitor, inductor, and RF generator forms a resonance circuit to enhance sensitivity by measuring alternating electric current variations based on capacitance changes induced by the DC electric field.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a variable capacitor is used in a semiconductor-based DC electrometer, then the device can operate without moving parts and reduce malfunctions, but the sensitivity is reduced due to small capacitance variation

Engineering Contradiction:

ImprovereliabilityVSAvoidsensitivity

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent changes the operating parameters of the variable capacitor by applying a DC electric field to modify its capacitance characteristics. This allows the capacitor to operate in a regime where small physical changes produce measurable electrical effects, thereby improving sensitivity while maintaining the reliability of contactless operation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies an oscillating DC electric field to the variable capacitor, inducing periodic changes in capacitance that amplify the measurement signal. This vibration-like modulation transforms static capacitance changes into dynamic signals that are easier to detect and measure with high precision

Inventive Principle:

Principle #18Mechanical vibration

2Measurement precision

If the capacitance of the variable capacitor is increased to improve sensitivity, then the measurement range is limited and calibration is required frequently

Engineering Contradiction:

ImprovesensitivityVSAvoidmeasurement range

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent makes the capacitor value dynamic by applying a time-varying DC electric field rather than using a fixed capacitor. This dynamic adjustment allows the system to adapt to different measurement ranges and eliminates the need for frequent calibration, as the capacitor can be electronically reconfigured for different measurement conditions

Inventive Principle:

Principle #15Dynamics

3Measurement precision

If a rotatable electrode type electrometer is used to achieve high sensitivity, then the measurement range is wide, but the device requires electric power for motor operation and has limited measurement speed

Engineering Contradiction:

ImprovesensitivityVSAvoidelectric power consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent replaces the mechanical rotation system with an electronic field-based system. Instead of physically rotating electrodes to change capacitance, the invention uses a DC electric field to modulate the capacitance of a fixed variable capacitor, thereby eliminating motor power requirements while maintaining sensitivity through electronic means

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Adaptability or versatility

If a rotatable electrode type electrometer is used to achieve wide measurement range, then high sensitivity is secured, but foreign matter often causes malfunction during long-term operation

Engineering Contradiction:

Improvemeasurement rangeVSAvoidreliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent eliminates the mechanical rotating electrode system entirely and replaces it with a contactless field-based measurement system. This substitution removes the vulnerability to foreign matter infiltration while preserving the ability to measure across a wide range of electric field conditions through electronic capacitor modulation

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 wide measurement range while reducing malfunctions by increasing alternating electric current variations through resonance, facilitating easy integration with IC circuits and size reduction.

Implementation Method 1

a variable capacitor having a capacitance value varying depending upon the magnitude of voltage of the DC electric field applied to the sensor plate

Methodology Applied

Scientific EffectCapacitance variation due to electric field: Capacitance

Implementation Method 2

an inductor connected in series to the variable capacitor to form a resonance circuit; measuring the magnitude of alternating electric current flowing through the resonance circuit according to a resonance frequency

Methodology Applied

Scientific EffectResonance: Resonance

Data Source

PatentUS12510579B2Contactless DC electric-field sensor

Publication Date: 2025.12.30 KOREA ELECTROTECH RES INST

AI summary

Disclosed herein is a contactless DC electric-field sensor having improved sensitivity. The contactless DC electric-field sensor has a circuit composed of a variable capacitor and an RF generator and improves sensitivity through resonance of the circuit by connecting an inductor to the sensor.