Piezoelectric Microspeaker Diaphragm Segmentation for Power Output
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Solution Overview
Problem
Piezoelectric microspeakers have lower power output compared to conventional voice coil microspeakers, limiting their adoption in mobile electronic devices despite their potential for miniaturization and lower voltage operation.
Innovation Solution
A piezoelectric microspeaker design featuring a substrate with a through hole, a diaphragm divided into actuating and non-actuating portions of different dielectric materials, and piezoelectric actuators with central and edge components, allowing for increased displacement and power output by optimizing the structure and materials used.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If piezoelectric microspeakers are designed for miniaturization and lower voltage operation, then device size and voltage requirements are reduced, but power output decreases
Solution Approach 1:
The diaphragm is divided into multiple regions with different materials: a first region with high elastic modulus (ceramic or glass) for structural support and a second region with low elastic modulus (polymer) for vibration. This segmentation allows the small device to maintain structural integrity while enabling effective vibration for power output.
Solution Approach 2:
The diaphragm uses a composite structure combining ceramic/glass materials (high elastic modulus) with polymer materials (low elastic modulus). This composite approach allows the miniaturized device to achieve both structural rigidity and vibration capability, resolving the power output limitation.
2Volume of moving object
If piezoelectric microspeakers are designed for miniaturization, then device size is reduced, but displacement capability decreases
Solution Approach 1:
Different regions of the diaphragm have different material properties optimized for their specific functions. The first region (ceramic/glass) provides local structural support while the second region (polymer) provides local vibration capability, enabling sufficient displacement in a miniaturized device.
Solution Approach 2:
The piezoelectric actuators are positioned to apply dynamic forces that maximize displacement of the diaphragm's second region. The combination of piezoelectric actuation with the compliant polymer region enables greater displacement capability in the miniaturized structure.
3Ease of manufacture
If conventional single-material diaphragms are used, then manufacturing is simpler, but power output and displacement are limited
Solution Approach 1:
The diaphragm is segmented into multiple material regions that can be manufactured using sequential deposition or lamination processes. This segmentation enables enhanced power output while maintaining compatibility with standard MEMS manufacturing techniques.
Solution Approach 2:
The composite diaphragm structure combines ceramic/glass and polymer materials in a layered or regioned configuration. This composite approach enhances power output and displacement while being manufacturable using existing multi-layer fabrication processes.
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 design achieves higher power output and displacement, maintaining performance over time, making it suitable for use in mobile electronic devices.
Implementation Method 1
The piezoelectric effect is the reversible conversion of mechanical energy into electrical energy using a piezoelectric material. In other words, the piezoelectric effect is a phenomenon in which an electric potential difference is generated when pressure or vibration is applied to a piezoelectric material, and the piezoelectric material deforms or vibrates when an electric potential difference is applied.
Data Source
AI summary
A piezoelectric microspeaker and a method of fabricating the same are provided. The piezoelectric microspeaker includes a substrate having a through hole therein; a diaphragm disposed on the substrate and covering the through hole; and a plurality of piezoelectric actuators including a piezoelectric member, a first electrode, and a second electrode, wherein the first and second electrodes are configured to induce an electric field in the piezoelectric member. The piezoelectric actuators include a central actuator, which is disposed on a central portion of the diaphragm and a plurality of edge actuators, which are disposed a predetermined distance apart from the central actuator and are formed on a plurality of edge portions of the diaphragm.