Electrostatic Actuator Layout for Stable Resonance Amplitude

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Electrostatic actuators face instability in vibration due to non-linear amplitude changes with input voltage, leading to complex control requirements for gyro sensors, as resonance frequency shifts with amplitude increases, resulting in multiple solutions for amplitude frequency relationships.

Innovation Solution

The introduction of an attractive force between the movable and fixed electrodes reduces non-linear vibration by combining a slide-type and squeezed-type electrostatic actuator configuration, allowing for linear amplitude control with respect to input voltage through specific electrode arrangements and voltage application methods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If voltage is applied to the fixed electrode and movable electrode to increase vibration amplitude, then the vibration amplitude increases, but non-linear vibration increases and resonance frequency shifts causing multiple solutions

Engineering Contradiction:

Improvevibration amplitudeVSAvoidresonance frequency stability

Core Design Contradiction:

SpeedVSStability of the object's composition

Solution Approach 1:

A third electrode is introduced as an intermediary element between the fixed electrode and movable electrode. This third electrode applies an attractive force that acts as a mediator to suppress non-linear vibrations of the movable electrode, allowing larger vibration amplitudes to be achieved while maintaining resonance frequency stability and avoiding multiple solution problems

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the electrostatic field configuration by introducing a third electrode with specific voltage application. This parameter change in the electric field distribution creates an attractive force that modifies the vibration characteristics, suppressing non-linear effects and stabilizing the resonance frequency across different amplitude levels

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If vibration amplitude is increased for better sensor performance, then sensitivity improves, but controllability deteriorates due to non-linear amplitude-frequency relationships

Engineering Contradiction:

Improvesensor sensitivityVSAvoidamplitude controllability

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The third electrode serves as a mediator that provides stabilizing attractive force, enabling the movable electrode to achieve larger vibration amplitudes required for high sensitivity while maintaining predictable and controllable amplitude-frequency relationships, thus improving both sensitivity and controllability simultaneously

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If a simple electrostatic actuator configuration is used, then device complexity is reduced, but non-linear vibration causes control difficulties

Engineering Contradiction:

Improveelectrode configurationVSAvoidvibration control

Core Design Contradiction:

Device complexityVSEase of operation

Solution Approach 1:

By introducing a third electrode as an intermediary, the system adds a controlled element that suppresses non-linear vibrations. This moderate increase in complexity directly improves vibration control characteristics, making the actuator more predictable and easier to control while maintaining reasonable device simplicity

Inventive Principle:

Principle #24Intermediary (Mediator)

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 stabilizes the amplitude control of the movable electrode, widening the amplitude range for unique frequency solutions, thereby improving controllability and reducing resonance curve inclination towards high frequencies.

Implementation Method 1

vibrates the movable electrode by an electrostatic force that acts between the electrodes

Methodology Applied

Scientific EffectElectrostatic force: Electrostatics

Implementation Method 2

an attractive force acts between the movable electrode and the fixed portion. Non-linear vibration of the movable electrode when a voltage is applied to the fixed electrode and the movable electrode is reduced by the attraction force

Methodology Applied

Scientific EffectAttractive force: Electrostatics

Data Source

PatentUS11846651B2Electrostatic actuator and physical quantity sensor

Publication Date: 2023.12.19 DENSO CORP

AI summary

An electrostatic actuator includes a fixed electrode and a movable electrode arranged to face the fixed electrode. The movable electrode is configured to be displaceable with respect to the fixed electrode and a fixed portion. An attractive force acts between the movable electrode and the fixed portion. In the electrostatic actuator, a non-linear vibration of the movable electrode when a voltage is applied to the fixed electrode and the movable electrode is reduced by the attractive force acting between the movable electrode and the fixed portion.