MEMS Sensor Beam Meshwork Anchoring

Solution Overview

Problem

Existing MEMS sensors face challenges in ensuring 100% fixation of the sensor element against turning movements around the z-axis due to the critical nature of manufacturing long spring elements, which can lead to erroneous signal generation from shock movements.

Innovation Solution

The use of a beam meshwork that stabilizes the sensor element against turning movements around the driving axis while allowing torsion, enabling defined deflection around the sensor axis, with the meshwork extending along the x-y plane and designed to resist movements around the x-axis while facilitating tilting around the y-axis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If long spring elements are used to fasten the sensor element to the central anchor, then the sensor element can be connected to the substrate, but the manufacturing precision deteriorates because the spring elements are critical and cannot ensure 100% fixation against turning movements

Engineering Contradiction:

Improvefixation of sensor elementVSAvoidfixation accuracy

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The connecting element is divided into multiple individual beams arranged in a meshwork pattern, where each beam contributes to the overall stabilization. This segmentation allows for better manufacturing control and ensures reliable fixation without relying on single long spring elements

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The meshwork structure provides different levels of stiffness in different directions: high stiffness against turning movements around the z-axis (driving axis) and controlled flexibility allowing torsion around the y-axis (sensor axis). This local differentiation of mechanical properties achieves both stable fixation and necessary movement freedom

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If the sensor element is firmly fixed to prevent turning movement, then manufacturing precision improves, but the sensor element cannot deflect around the sensor axis when Coriolis force acts upon it

Engineering Contradiction:

Improvefixation accuracyVSAvoiddeflection capability

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The meshwork structure provides different levels of stiffness in different directions: high stiffness against turning movements around the z-axis (driving axis) and controlled flexibility allowing torsion around the y-axis (sensor axis). This local differentiation of mechanical properties achieves both stable fixation and necessary movement freedom

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The connecting element is designed to be dynamic rather than static - it automatically adjusts its deformation based on the direction and magnitude of applied forces, allowing torsion when needed while resisting unwanted turning movements

Inventive Principle:

Principle #15Dynamics

3Reliability

If the meshwork is made very stiff to prevent turning movement, then reliability improves, but the meshwork cannot allow necessary torsion for sensor element deflection

Engineering Contradiction:

Improveresistance to turning movementVSAvoidtorsion capability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The meshwork structure provides different levels of stiffness in different directions: high stiffness against turning movements around the z-axis (driving axis) and controlled flexibility allowing torsion around the y-axis (sensor axis). This local differentiation of mechanical properties achieves both stable fixation and necessary movement freedom

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The meshwork is designed with asymmetric beam arrangements and hole patterns that create different mechanical responses in different directions, allowing the structure to be stiff in one direction while flexible in another

Inventive Principle:

Principle #4Asymmetry

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 design effectively prevents sensor element movement around the driving axis while allowing precise deflection due to Coriolis forces, reducing erroneous signal generation and enhancing the sensor's resistance to shock movements.

Implementation Method 1

the meshwork has been executed to allow its torsion, which in turn allows a turning movement of the sensor element around the sensor axis

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

When the sensor turns around a predefined axis, a sensor element intended for the MEMS sensor is deflected owing to the Coriolis force that occurs when this is done

Methodology Applied

Scientific EffectCoriolis force: Coriolis Force

Data Source

PatentUS8322212B2MEMS rotational sensor with improved anchoring

Publication Date: 2012.12.04 HANKING ELECTRONICS HONGKONG CO LTD

AI summary

A MEMS sensor is provided with a substrate and a sensor element. The sensor element moves in response to an influence registered by the sensor primarily in an oscillating turn around a sensor axis that is parallel to the substrate. The sensor has an anchor arranged on the substrate in order to hold the sensor element onto the substrate. A connecting element arranges the sensor element on the anchor.