Piezoelectric Ultrasonic Transducer Array with Switched Modes

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Solution Overview

Problem

Existing micromachined transducer arrays face challenges in operating in multiple modes due to complex device interconnection and fixed single-mode architectures, which limits their performance and applications.

Innovation Solution

Integration of MEMS switches with transducer elements to enable switchable operational modes, allowing transducers to be interconnected in various electrical configurations, such as parallel and series, through MEMS switches, which can be controlled by a switch controller to adapt to different operational modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If transducer arrays are designed with fixed single-mode operation architecture, then device interconnection complexity is reduced, but adaptability and versatility are limited

Engineering Contradiction:
Improvedevice interconnection complexityVSAvoidoperational mode adaptability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic reconfiguration of transducer array interconnect topologies using MEMS switches that can change the electrical connection configuration between transducer elements based on operational mode requirements. The system transitions from fixed single-mode operation to multi-mode operation by dynamically switching between series and parallel connections, allowing the same physical array to adapt to different operational modes without increasing permanent interconnection complexity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent creates a universal transducer array architecture that can perform multiple operational modes (e.g., transmit, receive, full duplex) using the same physical transducer elements and interconnection structure. By incorporating MEMS switches, the system achieves multi-functionality where a single array design serves multiple purposes, eliminating the need for separate dedicated arrays for different modes

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

2Adaptability or versatility

If transducer arrays are designed for multi-mode operation, then adaptability and versatility are improved, but device interconnection complexity increases

Engineering Contradiction:
Improveoperational mode adaptabilityVSAvoiddevice interconnection complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the interconnection function by introducing separate MEMS switch elements that control individual connection paths between transducer elements. Instead of complex monolithic interconnection structures, the system divides the switching function into discrete controllable segments, where each MEMS switch independently manages specific connection states, thereby reducing overall interconnection complexity while enabling multi-mode operation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces MEMS switches as intermediary elements between transducer elements and control circuitry. These intermediary switches simplify the direct interconnection complexity by providing controlled access points that manage signal routing between different operational modes, acting as mediators that reduce the burden on both transducer elements and control systems

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If MEMS switches are integrated with transducer elements, then multi-mode operation is enabled, but manufacturing complexity increases

Engineering Contradiction:
Improveswitchable operational modesVSAvoidfabrication complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent merges the MEMS switch fabrication process with the existing transducer array manufacturing process. By integrating switch element deposition, patterning, and bonding steps into the established micromachining workflow, the system achieves multi-mode functionality without requiring separate complex fabrication lines. The combined process leverages common materials and techniques from both transducer and MEMS manufacturing

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent utilizes parameter changes in the fabrication process, such as adjusting deposition conditions, etch parameters, and bonding temperatures, to optimize the integration of MEMS switches with transducer elements. By carefully controlling these parameters, the system maintains manufacturing feasibility while achieving the desired functional integration, avoiding excessive complexity in the fabrication process

Inventive Principle:
Principle #35Parameter changes

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 complexity of interconnection and allows for multi-mode operation, enhancing the performance and versatility of transducer arrays by dynamically reconfiguring interconnect topologies, thereby supporting both drive and sense modes with reduced overhead.

Implementation Method 1

piezoelectric transducer elements include a piezoelectric membrane capable of mechanical deflection of the membrane in response to a time-varying driving voltage

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

The same piezoelectric membrane can also receive reflected pressure waves from the propagation media and convert the received pressure waves into electrical signals

Methodology Applied
Scientific EffectPiezoelectric effect: Converse Piezoelectric Effect

Implementation Method 3

one or more first piezoelectric transducer element of an array is interconnected to one or more second piezoelectric transducer element of the array through at least one MEMS switch to provide switchable operational modes of the array

Methodology Applied
Scientific EffectMEMS switching: Microelectromechanical Systems

Data Source

PatentEP3053203B1Piezoelectric ultrasonic transducer array with switched operational modes
Publication Date: 2019.08.07 FUJIFILM DIMATIX INC
  • EP3053203B1 patent drawingFigure 1A
  • EP3053203B1 patent drawingFigure 1B~1E
  • EP3053203B1 patent drawingFigure 2A~2C

AI summary

Switchable micromachined transducer arrays are described where one or more switches, or relays, are monolithically integrated with transducer elements in a piezoelectric micromachined transducer array (pMUT). In embodiments, a MEMS switch is implemented on the same substrate as the transducer array for switching operational modes of the transducer array. In embodiments, a plurality of transducers are interconnected in parallel through MEMS switch(es) in a first operational mode (e.g., a drive mode) during a first time period, and are then interconnected through the MEMS switch(es) with at least some of the transducers in series in a second operational mode (e.g., a sense mode) during a second time period.