Corrugated MEMS Speaker for Compact Electrostatic Sound Generation
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Solution Overview
Problem
Existing electronic devices, particularly compact devices, face challenges in providing high-quality sound output due to space constraints and the need for efficient sound generation without traditional speaker components like magnets and coils.
Innovation Solution
A low-power, compact speaker utilizing an electrostatically driven, corrugated MEMS structure that moves air without a magnet or coil, featuring corrugated MEMS structures between substrates to generate sound through pressure differentials, with adjustable electrode spacing and multiple layers for enhanced sound production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If traditional speaker components (magnets and coils) are used, then sound generation is achieved, but device size increases and power consumption rises
Solution Approach 1:
The patent replaces the traditional electromagnetic speaker system (magnets and coils) with an electrostatic MEMS-based system. The electrostatic actuation uses electric fields between electrodes to deform the diaphragm, eliminating the need for heavy magnetic components and reducing power consumption while achieving the same sound generation function
Solution Approach 2:
The patent introduces corrugated folds in the MEMS diaphragm structure, adding a third dimension to the otherwise planar membrane. This corrugation increases the acoustic surface area without increasing the planar footprint, allowing more air to be moved for sound generation within a smaller device volume
2Volume of moving object
If traditional speaker components are used, then sound output is generated, but the device form factor increases
Solution Approach 1:
The corrugated MEMS structure folds the diaphragm into multiple layers, dramatically increasing the acoustic surface area within a compact footprint. This allows the speaker to move more air and generate higher quality sound output while maintaining a small device form factor
Solution Approach 2:
The multi-layer corrugated MEMS structure nests multiple acoustic surfaces within a compact volume. The folded diaphragm creates inner and outer surfaces that both contribute to sound generation, effectively packing more acoustic functionality into a smaller space
3Area of moving object
If electrode spacing is increased, then acoustic surface area increases, but device volume increases
Solution Approach 1:
The corrugated MEMS structure utilizes the third dimension (vertical folding) to increase acoustic surface area. By folding the diaphragm into corrugations, the design achieves large acoustic area without increasing the planar footprint or overall device volume
Solution Approach 2:
The patent employs adjustable electrode spacing that can be dynamically controlled. By varying the voltage applied to different electrode pairs, the spacing between diaphragm layers can be adjusted, allowing optimization of acoustic surface area while maintaining compact device volume through electrostatic control
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
The MEMS speaker achieves high-quality sound output in a small form factor by efficiently utilizing a MEMS structure with corrugated folds and electrostatic actuation, providing a large acoustically active area in a small volume.
Implementation Method 1
A low-power, compact speaker includes an electrostatically driven, corrugated microelectromechanical systems (MEMS) structure
Implementation Method 2
deforming the corrugated MEMS structure to generate sound by moving air without a magnet or coil
Data Source
AI summary
Aspects of the subject technology relate to electronic devices having speakers such as microelectromechanical systems (MEMS) speakers. A MEMS speaker can include an electrostatically driven, corrugated MEMS structure to move air without a magnet, coil, or traditional speaker membrane, and thus provide a low-power, compact speaker with a large acoustically active area in a small volume. Neighboring folds in the corrugated MEMS structure may form pairs of MEMS electrodes that can be pushed together and/or pulled apart to deform the MEMS structure in a breathing motion that generates pressure differentials on opposing sides of the corrugated MEMS structure to generate sound. Additional modes of operation are described.