MEMS Microphone Lever Tilting Mechanism
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Solution Overview
Problem
Existing MEMS microphones face challenges in achieving high sensitivity, low noise, and good linearity while maintaining robustness against media and particles, and they often require complex designs to prevent membrane damping and ensure signal quality.
Innovation Solution
The design incorporates a membrane anchored to a substrate, a lever element coupled to the membrane and signal transduction element, which generates a tilting movement to transmit sound pressure deflections, allowing for a thin, lightweight membrane with high robustness and efficient signal transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a membrane is used to detect sound pressure, then sensitivity is improved, but the membrane movement becomes damped and signal quality deteriorates
Solution Approach 1:
A lever element is introduced as an intermediary between the membrane and the signal transduction element. The lever element converts the membrane's linear deflection into a tilting movement that is transmitted to the signal transduction element, thereby improving signal quality while maintaining sensitivity.
2Reliability
If a thick membrane is used to increase robustness, then media robustness is improved, but the membrane becomes heavier and less sensitive
Solution Approach 1:
The lever element acts as a mechanical amplifier that compensates for the thin membrane's reduced robustness. By converting small deflections into amplified tilting movements, the system achieves high sensitivity without requiring a thick, heavy membrane.
Solution Approach 2:
The membrane thickness is reduced to less than 4 μm (e.g., 2 μm) to decrease mass and improve sensitivity, while the lever element's mechanical advantage compensates for the reduced structural robustness, maintaining overall system reliability.
3Reliability
If the membrane is anchored all around to the substrate, then robustness is improved, but the membrane cannot stabilize itself
Solution Approach 1:
The lever element serves as a mediator that decouples the membrane from direct rigid anchoring requirements. The membrane can be fully anchored to the substrate for robustness, while the lever element provides the necessary mechanical freedom to convert deflections into tilting movements without requiring membrane self-stabilization.
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 configuration results in a sensitive MEMS microphone with low noise and good linearity, offering robustness against media and particles, while simplifying production and reducing costs.
Implementation Method 1
a membrane (103) for absorbing sound pressure
Implementation Method 2
a lever element (109), coupled to the membrane (103) and the signal transduction element (111), wherein the lever element (109) is configured, when the membrane (103) is deflected, to generate a tilting movement and to transmit the generated tilting movement to the signal transduction element (111)
Implementation Method 3
Based on the transmitted tilting movement, such a signal transduction element generates, for example, a capacitive signal, which depends on the deflection and thus on the sound pressure
Data Source
AI summary
A MEMS microphone. The MEMS microphone includes: a membrane for absorbing sound pressure; a signal transduction element; and a lever element, coupled to the membrane and the signal transduction element. The lever element is configured, when the membrane is deflected, to generate a tilting movement and to transmit the generated tilting movement to the signal transduction element.