Impedance Matching Body Microstructures Acoustic Energy Transfer
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Solution Overview
Problem
Existing acoustic impedance matching devices suffer from low efficiency in adjusting acoustic impedance between sound transducers and media, particularly in achieving low acoustic impedances without disrupting transmission behavior.
Innovation Solution
The use of microstructures with structural dimensions of at most 500 nanometers, featuring branched microchannels with varying numbers and tapering shapes, which monotonically adjust the effective material density to match acoustic impedances between sound transducers and media, enabling precise and efficient impedance matching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional materials with suitable acoustic impedance are used to adjust acoustic impedance, then the acoustic impedance can be matched, but the transmission efficiency is reduced due to significant impedance jump
Solution Approach 1:
The impedance matching layer is divided into multiple sub-layers with progressively different acoustic impedances. Each sub-layer has a thickness of 1-10 micrometers and creates a gradual impedance transition rather than a single abrupt step, reducing energy reflection at each interface and improving overall transmission efficiency
Solution Approach 2:
Different regions of the impedance matching layer have different acoustic impedances tailored to specific locations. The first sub-layer has acoustic impedance closer to the piezoelectric element, while subsequent sub-layers have progressively lower acoustic impedances, creating a localized gradient that optimizes energy transfer at each position
2Reliability
If aerogels are used to achieve very low acoustic impedance, then the acoustic impedance can be reduced significantly, but diffraction effects increase and transmission behavior is impaired
Solution Approach 1:
The impedance matching layer uses a porous composite structure with voids filled with acoustic matching material. The porosity provides a gradual impedance transition without the strong diffraction effects associated with aerogels, while still achieving significant acoustic impedance reduction through the controlled void fraction and material composition
3Reliability
If composite materials with embedded particles are used to adjust acoustic impedance, then the acoustic impedance can be modified, but transmission behavior is impaired due to intermediate bonding materials
Solution Approach 1:
The impedance matching layer uses a composite material consisting of a piezoelectric element matrix with embedded voids filled with acoustic matching material. This composite structure eliminates the need for intermediate bonding materials between different impedance layers, as the void-filled composite itself forms the gradual impedance transition, thereby improving transmission behavior
4Manufacturing precision
If microstructures with small dimensions are formed to achieve precise acoustic impedance adjustment, then the acoustic impedance can be precisely controlled, but manufacturing complexity increases
Solution Approach 1:
The impedance matching is achieved by varying the thickness of multiple sub-layers in the vertical dimension rather than requiring complex lateral microstructures. Each sub-layer has a controlled thickness between 1-10 micrometers, allowing precise impedance adjustment through simple thickness control during fabrication, thereby reducing manufacturing complexity while maintaining precision
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 continuous and efficient acoustic impedance adjustment, enhancing energy transfer between sound transducers and media by precisely controlling the acoustic impedance curve, thereby improving the transmission efficiency and reducing diffraction effects.
Implementation Method 1
The microchannels form cavities in the impedance matching body, wherein an effective material density of an impedance matching material of the impedance matching body varies monotonically between the first side and the second side due to a monotonous increase or decrease in the volume of the cavities, and effects the adaptation of the acoustic characteristic impedance
Implementation Method 2
This approach allows for continuous and efficient acoustic impedance adjustment, enhancing energy transfer between sound transducers and media by precisely controlling the acoustic impedance curve, thereby improving the transmission efficiency and reducing diffraction effects
Data Source
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AI summary
The invention relates to an impedance matching device for matching an acoustic characteristic impedance, comprising an impedance matching body having a first side an an opposite, second side. The impedance matching device is designed to match an acoustic characteristic impedance of a medium contacted on the first side to an acoustic characteristic impedance of a sound converter contacted on the second side. The impedance matching body comprises microstructures which have a structural extent of at least 500 nanometres in at least one spatial direction.