MEMS Motion Limiter With Flexible Shock Absorber for Rotor Impact

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing microelectromechanical (MEMS) devices face issues with undesired contact between mobile and stationary parts due to external shocks, leading to structural damage, stiction, and particle release, which are not adequately addressed by conventional motion limiters that are rigidly fixed to the rotor and can cause further damage.

Innovation Solution

A microelectromechanical device with a mobile rotor and fixed stator, featuring a flexible shock absorber extending from the rotor to the stator and a fixed stopper structure, which aligns vertically to absorb impacts before the rotor contacts the fixed wall, using flexible springs to soften the impact and prevent direct contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a motion limiter bump is rigidly fixed to the rotor, then the bump can prevent direct contact between the rotor and fixed structure, but the rigid connection causes particles to be released during hard impact and can cause short-circuiting or other damage

Engineering Contradiction:

Improveprevention of direct contactVSAvoidparticle release

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The motion limiter element is made flexible rather than rigid, allowing it to deform during impact. This flexibility prevents particle release while maintaining the ability to limit motion and prevent direct contact between the rotor and fixed structure.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The mechanical properties of the motion limiter element are changed from rigid to flexible by modifying its material properties or structural parameters. This parameter change allows the element to absorb impact energy through deformation rather than fracturing and releasing particles.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If the rotor and suspension structure are dimensioned to avoid direct contact, then normal operation is maintained, but exceptional external shocks can still displace the rotor causing structural damage or stiction

Engineering Contradiction:

Improvenormal operationVSAvoidresistance to external shocks

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

A motion limiter element is pre-positioned between the rotor and fixed structure to provide preliminary protection. This element is designed to engage before the rotor can contact the fixed structure during exceptional shocks, preventing damage while not interfering with normal operation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The motion limiter element acts as an intermediary component between the rotor and fixed structure. It mediates the interaction by providing a controlled contact interface that prevents direct contact between the rotor and fixed structure during abnormal conditions.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If space is allocated for motion limiters, then protection against direct contact is improved, but device complexity and design constraints are increased

Engineering Contradiction:

Improveprotection against direct contactVSAvoiddesign constraints

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The motion limiter element is designed to serve multiple functions: it limits motion during shocks, prevents direct contact between rotor and fixed structure, and can be integrated with existing device components. This multi-functionality reduces the need for separate protection mechanisms and minimizes design constraints.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The motion limiter element is designed to fit within the existing device geometry, nesting it within available spaces without requiring additional external volume. This nesting approach minimizes the impact on device complexity and design constraints.

Inventive Principle:

Principle #7Nested doll (Nesting)

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 solution effectively prevents direct contact between the rotor and fixed structures, reducing damage and particle release by absorbing impacts with a softer collision, thereby maintaining device functionality and integrity.

Implementation Method 1

The shock absorber includes an impact part that is aligned with the fixed stopper structure in the vertical direction, one or more first shock absorber springs extending from the mobile rotor to the impact part, and one or more second shock absorber springs extending from the impact part to the fixed stator

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS12600620B2Low-impact out-of-plane motion limiter MEMS device

Publication Date: 2026.04.14 MURATA MFG CO LTD

AI summary

A microelectromechanical device is provided that includes a mobile rotor and a fixed stator in a device plane. Moreover, a fixed wall defines a wall plane that is adjacent to the device plane and a motion limiter is provided to prevent the rotor from coming into direct physical contact with the fixed wall. The motion limiter includes a shock absorber that extends from the rotor to the stator and a fixed stopper structure that protrudes from the fixed wall toward the shock absorber.