Balanced Flexural Resonator Structure for Low Energy Loss

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing flexural-vibration resonators suffer from vibrational energy losses and symmetry defects due to asymmetries caused by crystalline etching, leading to degraded quality factors and measurement biases in force sensors and gyrometers.

Innovation Solution

A resonator design with a vibrating portion having symmetrical extensions and a foot connection, featuring longitudinal slots and balanced momentum components, allowing for reduced vibrational energy loss and improved symmetry, utilizing monocrystalline piezoelectric materials like quartz.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If wet chemical etching is used to fabricate the resonator, then manufacturing simplicity and etching speed are improved, but symmetry defects and vibrational energy losses occur due to crystalline orientation asymmetries

Engineering Contradiction:
Improveetching process simplicityVSAvoidresonator symmetry
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies asymmetry by intentionally designing the resonator structure to compensate for the inherent asymmetry caused by wet chemical etching. The foot connection and extension geometries are specifically configured to counterbalance the etching-induced asymmetries, allowing the use of simple wet etching processes while achieving the required symmetry for high-quality factor operation.

Inventive Principle:
Principle #4Asymmetry

2Device complexity

If the resonator structure is simplified for ease of manufacture, then production complexity is reduced, but vibrational energy losses increase due to asymmetries

Engineering Contradiction:
Improveresonator structureVSAvoidvibrational energy loss
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent converts the harmful effect of etching asymmetries into a beneficial design feature. By analyzing the specific asymmetries introduced by wet etching, the design incorporates a foot connection and extension structure that transforms these asymmetries into balanced momentum components, thereby reducing vibrational energy losses while maintaining manufacturing simplicity.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Manufacturing precision

If symmetrical extensions are added to compensate for etching asymmetries, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:
Improveresonator symmetryVSAvoidresonator structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges the compensation function into the existing resonator structure by integrating the foot connection and extension design with the primary resonating elements. This unified structure achieves symmetry compensation without adding separate compensation components, thereby improving manufacturing precision while limiting the increase in device complexity.

Inventive Principle:
Principle #5Merging (Combining)

4Reliability

If the foot connection is optimized for dynamic balance, then quality factor is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvequality factorVSAvoidfoot connection symmetry
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The foot connection design incorporates geometric features that enable self-alignment and self-balancing during fabrication. The symmetrical extension geometry and foot configuration allow the structure to automatically compensate for minor manufacturing variations, achieving high quality factor performance without requiring extremely tight manufacturing tolerances.

Inventive Principle:
Principle #25Self-service

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 resonator achieves high quality factors with minimal energy loss and improved symmetry, enhancing the precision and accuracy of force sensors and gyrometers by compensating momentum components and maintaining dynamic balance.

Implementation Method 1

the piezoelectric tensor of trigonal class crystals offers optimal coupling for deformation Syy, i.e. along the axis of the beam, with an electrical field Exx. For this, the flexural vibration of the beam is excited by a direct piezoelectric effect using electrodes which are located along the beam in order to generate the electrical field Exx, and to detect deformations Syy via electrical charges generated by an indirect piezoelectric effect on these same electrodes.

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS12498222B2High-quality-factor flexural-vibration resonator for producing time references force sensors or gyrometers
Publication Date: 2025.12.16 OFFICE NAT DETUDES & DE RECH AEROSPATIALES
  • US12498222B2 patent drawing
  • US12498222B2 patent drawing
  • US12498222B2 patent drawing

AI summary

A resonator is suitable for reducing or suppressing a force transmitted by a vibrating portion of the resonator to a support part. To this end, the vibrating portion includes two extensions which are each meander shaped such that two segments of each extension have respective speed components that are oriented in opposite directions. Such a resonator, which is balanced, can advantageously be used within a rate gyro or a force sensor.