Piezoelectric Acoustic Device with Flexible Suspension
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Solution Overview
Problem
Conventional piezoelectric acoustic devices suffer from insufficient performance due to fixed clamping in a rigid frame, leading to high base frequency, small amplitude range, and restricted effective area, making them unsuitable for applications in mobile devices.
Innovation Solution
A piezoelectric speaker or microphone design where the piezoelectric active membrane is flexibly received on a frame, allowing translational motion in the x and y directions while inhibiting motion in the z-direction, using a soft foam ring and rigid pillars for suspension, which enhances mechanical flexibility and resonant frequency characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the piezoelectric membrane is rigidly clamped in a fixed frame, then the structural stability is improved, but the mechanical flexibility and resonant frequency characteristics deteriorate
Solution Approach 1:
The frame is segmented into fixed portions and movable portions, allowing different regions to serve different functions. The fixed portions provide structural stability while the movable portions enable mechanical flexibility and improved resonant frequency characteristics.
Solution Approach 2:
Different regions of the frame are given different mechanical properties - some regions are rigid for stability while others are flexible for resonant frequency optimization. This local differentiation resolves the contradiction between overall stability and local flexibility.
2Manufacturing precision
If the piezoelectric membrane is rigidly clamped, then the positional stability is improved, but the effective area and amplitude range deteriorate
Solution Approach 1:
The clamping structure transitions from a static rigid clamp to a dynamic system where the membrane can move within defined parameters. The movable portions of the frame allow the membrane to expand its effective area and amplitude range while maintaining positional stability through controlled boundaries.
3Strength
If the piezoelectric membrane is rigidly clamped, then the structural integrity is improved, but the audio detection and playback accuracy deteriorate
Solution Approach 1:
The clamping structure is divided into segments that independently maintain structural integrity while allowing localized membrane movement. This segmentation preserves overall strength while enabling the fine movements necessary for accurate audio detection and playback.
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 design significantly improves audio detection and playback accuracy, increases the effective area, and reduces resonant frequency, enabling the implementation of piezoelectric devices in portable devices like mobile phones with improved loudness and frequency response.
Implementation Method 1
a piezoelectric active membrane is flexibly received on/in a frame
Implementation Method 2
The suspension may comprise a soft foam ring in combination with, for instance, four rigid pillars
Data Source
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AI summary
An acoustic device (500), comprising an oscillatory membrane (501) which comprises a transducing element (503) and a frame (504) adapted for accommodating the membrane (501) in an accommodation plane, wherein the membrane (501) is accommodated in the frame (504) in such a manner that a translational motion of the membrane (501) in at least one direction of the accommodation plane is made possible.