Multi-Layer Piezoelectric MEMS Transducer for Frequency Versatility

Solution Overview

Problem

Current ultrasonic MEMS transducers operate at a single frequency due to their physical parameters, requiring multiple transducers of different sizes for applications needing various frequencies, which occupies space and compromises sensor resolution.

Innovation Solution

A MEMS device with multiple piezoelectric layers and electrode regions, where each layer receives a distinct electrical signal to generate vibrations, allowing for the superposition of frequencies through acoustic mixing, enabling the generation of multiple frequencies within the footprint of a single-frequency device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple transducers of different sizes are used to generate different frequencies, then frequency versatility is improved, but device area and sensor resolution deteriorate

Engineering Contradiction:

Improvefrequency versatilityVSAvoiddevice area

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The transducer is segmented into multiple piezoelectric layers (first piezoelectric layer, second piezoelectric layer) with different thicknesses, where each layer can be independently excited to generate different frequencies. This segmentation allows a single transducer to perform the function of multiple transducers with different sizes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The single transducer device is designed to perform multiple functions by generating different frequencies through different piezoelectric layers. The device can operate as a multi-frequency transducer, eliminating the need for separate transducers for different frequency requirements.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If multiple transducers of different sizes are used to generate different frequencies, then frequency versatility is improved, but sensor resolution deteriorates

Engineering Contradiction:

Improvefrequency versatilityVSAvoidsensor resolution

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The transducer is segmented into multiple piezoelectric layers (first piezoelectric layer, second piezoelectric layer) with different thicknesses, where each layer can be independently excited to generate different frequencies. This segmentation allows a single transducer to perform the function of multiple transducers with different sizes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The single transducer device is designed to perform multiple functions by generating different frequencies through different piezoelectric layers. The device can operate as a multi-frequency transducer, eliminating the need for separate transducers for different frequency requirements.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Device complexity

If a single piezoelectric layer is used, then device simplicity is improved, but frequency versatility deteriorates

Engineering Contradiction:

Improvedevice simplicityVSAvoidfrequency versatility

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The transducer is segmented into multiple piezoelectric layers (first piezoelectric layer, second piezoelectric layer) with different thicknesses, where each layer can be independently excited to generate different frequencies. This segmentation allows a single transducer to perform the function of multiple transducers with different sizes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The device structure is made dynamic by enabling selective activation of different piezoelectric layers based on the required frequency. The system can adapt its configuration by engaging only the necessary layers for the current operating frequency, optimizing performance while maintaining simplicity.

Inventive Principle:

Principle #15Dynamics

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

Enables the generation of multiple frequencies using a single MEMS device, reducing space requirements and improving sensor resolution by allowing the same device to operate in various frequency modes for different applications.

Implementation Method 1

a first piezoelectric layer arranged over the first electrode region; a second piezoelectric layer arranged over the first piezoelectric layer and the second electrode region

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS11185886B2Microelectromechanical systems, devices, and methods for fabricating a microelectromechanical systems device, and methods for generating a plurality of frequencies

Publication Date: 2021.11.30 VANGUARD INT SEMICON SINGAPORE PTE LTD

AI summary

A MEMS device may include a first electrode region; a first piezoelectric layer arranged over the first electrode region; a second electrode region arranged over the first piezoelectric layer; a second piezoelectric layer arranged over the first piezoelectric layer and the second electrode region; a third electrode region arranged over the second piezoelectric layer; a first input port coupled to the first electrode region and/or the second electrode region for providing a first electrical signal to the first piezoelectric layer to generate a first vibration in the first piezoelectric layer; a second input port coupled to the second electrode region and/or the third electrode region for providing a second electrical signal to the second piezoelectric layer to generate a second vibration in the second piezoelectric layer; and an output port configured to receive an output signal including a superposition of the first vibration and the second vibration.