Piezoelectric MEMS Switch with Segmented Electrodes for Low-Voltage Actuation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Micro-electromechanical switches (MEMS) face challenges in achieving low switching voltages while maintaining mechanical stability, particularly for applications requiring voltages below 5 V, which limits their use in mobile telecommunications and other low-voltage scenarios.

Innovation Solution

The design involves structuring at least one electrode layer to create a displacement area within the piezoelectric element, allowing for localized deformation and movement of the first MEMS electrode relative to the substrate, enabling strong displacement at low actuating voltages without deflecting the entire element, thus enhancing mechanical stability and reducing switching voltages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the entire piezoelectric element is deflected, then the switching voltage is reduced, but the mechanical stability deteriorates

Engineering Contradiction:

Improveswitching voltageVSAvoidmechanical stability

Core Design Contradiction:

Use of energy by moving objectVSStability of the object's composition

Solution Approach 1:

The piezoelectric element is divided into a deformable displacement area and a stable support area. The displacement area contains the piezoelectric layer with electrodes that are selectively deactivated in portions, creating a segmented structure that allows localized deformation while maintaining overall structural integrity and mechanical stability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the piezoelectric element are assigned different functional properties: the displacement area is designed to be deformable with selectively deactivated electrode portions to enable movement, while the support area maintains full electrode activation to provide mechanical stability and structural reinforcement.

Inventive Principle:

Principle #3Local quality

2Stability of the object's composition

If the piezoelectric element is made more rigid for stability, then mechanical stability improves, but the switching voltage increases

Engineering Contradiction:

Improvemechanical stabilityVSAvoidswitching voltage

Core Design Contradiction:

Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

The element is segmented into rigid support regions with fully active electrodes and flexible displacement regions with selectively deactivated electrodes, allowing the rigid portions to provide stability while the flexible portions enable movement at low voltages.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Local quality is applied by giving different regions different mechanical and electrical properties: the support area has high rigidity and full electrode activation, while the displacement area has reduced rigidity and partial electrode deactivation to facilitate low-voltage actuation.

Inventive Principle:

Principle #3Local quality

3Adaptability or versatility

If the switching voltage is reduced for low-voltage applications, then adaptability to mobile telecommunications improves, but the switching distance capability deteriorates

Engineering Contradiction:

Improveadaptability to low-voltage applicationsVSAvoidswitching distance

Core Design Contradiction:

Adaptability or versatilityVSLength of moving object

Solution Approach 1:

The electrode structure is segmented with selectively deactivated portions that create a localized displacement region, concentrating the deformation effect to achieve sufficient switching distance (over 1 μm) while using low actuating voltages suitable for mobile telecommunications.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Local quality is implemented by deactivating specific portions of the electrodes in the displacement area, which concentrates the piezoelectric effect in localized regions to generate adequate switching distance with low voltages, while maintaining full electrode coverage in support areas for structural integrity.

Inventive Principle:

Principle #3Local quality

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 approach allows for sufficient deformation to bridge switching distances of over 1 μm at low voltages, improving mechanical stability and reducing switching voltage requirements, making the MEMS switch suitable for mobile applications with minimized losses.

Implementation Method 1

a piezoelectric element with a piezoelectric layer located between a first and a second electrode layer, a first MEMS electrode being located on a surface of the piezoelectric element and said second MEMS electrode being located on the surface of a substrate, so that the first MEMS electrode moves away from and/or towards the second MEMS electrode under the application of an actuating voltage to the piezoelectric element

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS7952259B2Electronic apparatus with a micro-electromechanical switch made of a piezoeletric material

Publication Date: 2011.05.31 NXP BV

AI summary

The device improved according to the invention comprises a micro-electromechanical switch (MEMS) with a piezoelectric element connected to a mechanical support on both sides at the edges. The electrode design of this piezoelectric element is characterized by two electrodes mounted on at least one of the surfaces.