Floating Electrode Acoustofluidic Transducer Circuit

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Solution Overview

Problem

Existing acoustofluidic devices using two ultrasound transducers require complex drive circuits and are prone to interference due to the need for separate drive signals, increasing complexity and potential crosstalk.

Innovation Solution

A method and device utilizing a common electrode configuration where the electrical potential of the first electrodes floats, allowing a single drive signal to be applied between the second electrodes of the transducers, which capacitively and resistively propagates through the piezoelectric material, achieving a 180° phase shift without additional components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate drive signals are used for two ultrasound transducers, then each transducer can be independently controlled, but the device complexity and potential crosstalk increase

Engineering Contradiction:
Improveindependent control of transducersVSAvoiddrive circuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines two separate drive signals into a single drive signal that is applied to a common electrode shared by both ultrasound transducers. This merging approach reduces the number of electrical connections and circuit components while maintaining the ability to independently control each transducer through the single signal, thereby resolving the contradiction between independent control and device complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The common electrode serves multiple functions: it acts as an electrode for the first ultrasound transducer, an electrode for the second ultrasound transducer, and a shared reference point for both transducers. This multi-functionality allows a single drive signal to control both transducers effectively, reducing circuit complexity while maintaining independent control capability

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of operation

If two separate drive signals are applied to two ultrasound transducers, then each transducer can be driven independently, but the number of electrical components increases

Engineering Contradiction:
Improveindependent transducer drivingVSAvoidnumber of electrical components
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges the electrical connections by having both ultrasound transducers share a common electrode. A single drive signal is applied to this common electrode, eliminating the need for separate electrical connections and components for each transducer, thus reducing the total number of electrical components while maintaining independent driving capability through signal processing

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If conventional transducer connections are used, then each transducer has dedicated electrodes, but manufacturing complexity increases

Engineering Contradiction:
Improveelectrode connection reliabilityVSAvoidmanufacturing simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges the electrode structure by implementing a common electrode that serves both transducers. This reduces the number of discrete components that need to be assembled and connected during manufacturing, simplifying the fabrication process while maintaining reliable electrical connections through the shared electrode structure

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The common electrode is designed to fulfill multiple roles simultaneously - serving as an electrode for both transducers and providing a shared reference potential. This universal design reduces manufacturing steps and assembly complexity compared to implementing separate dedicated electrodes for each transducer

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 reduces the number of electrical components needed, simplifies manufacturing, and maintains efficient acoustophoretic processes by eliminating the need for separate drive signals, thus lowering costs and environmental impact.

Implementation Method 1

a first and a second ultrasound transducer, each provided in acoustic contact with the substrate for transferring ultrasonic vibrations to the substrate and causing the substrate to vibrate, wherein the first and the second ultrasound transducers each comprise a first electrode and a second electrode in contact with a piezoelectric or electrostrictive material

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

a first and a second ultrasound transducer, each provided in acoustic contact with the substrate for transferring ultrasonic vibrations to the substrate and causing the substrate to vibrate, wherein the first and the second ultrasound transducers each comprise a first electrode and a second electrode in contact with a piezoelectric or electrostrictive material

Methodology Applied
Scientific EffectElectrostriction: Electrostriction

Implementation Method 3

applying a drive signal between the second electrodes of the first and second ultrasound transducers, wherein the drive signal has a frequency f that corresponds to an acoustic resonance peak of one or more of the substrate, the microfluidic cavity filled with a fluid, and the transducers

Methodology Applied
Scientific EffectElectrical field: Electric Field

Implementation Method 4

a standing wave may appear in the channel. This standing wave exerts a force on the particles in the suspension dependent on the acoustic contrast of each individual particle

Methodology Applied
Scientific EffectAcoustic radiation pressure: Acoustic Radiation Pressure

Data Source

PatentEP4347124B1Acoustofluidic methods and devices using floating electrode
Publication Date: 2025.06.25 ACOUSORT
  • EP4347124B1 patent drawingFigure 1A~1B
  • EP4347124B1 patent drawingFigure 1C~2A
  • EP4347124B1 patent drawingFigure 2B~3

AI summary

A method of performing an acoustofluidic operation, comprising the steps of: a. providing (1) an acoustofluidic device (10) comprising: - a substrate (12) in which a microfluidic cavity (30) is positioned, and - at least a first (50a) and a second (50b) ultrasound transducer (50), each provided in acoustic contact with the substrate (12) for transferring ultrasonic vibrations to the substrate and causing the substrate to vibrate, wherein the first and the second ultrasound transducers each comprise a first electrode (52) and a second electrode (56a, 56b) in contact with a piezoelectric or electrostrictive material (54), and wherein the first electrodes are in electric contact with each other, b. providing a fluid, such as a liquid (2) or liquid suspension in the microfluidic cavity (30), c. applying (56a, 56b) of the first and second ultrasound transducers (50a, 50b), wherein the drive signal has a frequency f that corresponds to an acoustic resonance peak of one or more of the substrate, the microfluidic cavity filled with a fluid, and the transducers (50a, 50b), and d. letting the electrical potential of the first electrodes (52) float.