Capacitive Movable Electrode Structure to Prevent Pull-In Loss
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Solution Overview
Problem
Existing capacitive detection microphones suffer from energy loss and pull-in phenomena due to deformation of the transmission device and frame, which compromises the detection of dynamic pressure variations and increases the risk of electrode failure.
Innovation Solution
An electromechanical system with a movable electrode secured to the transmission device via pivot hinges, reducing energy loss by minimizing transformation elements and incorporating an elastic device to counteract pull-in, while maintaining a compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the transmission device and frame are used to transmit movement between the movable element and capacitive detection means, then the displacement can be measured, but energy is lost in the deformation of these components
Solution Approach 1:
The patent extracts the movable electrode from the deformation-prone transmission device by directly anchoring it to the piston, eliminating the intermediate transmission arms and shafts that cause energy loss through deformation while preserving the capacitive measurement function
Solution Approach 2:
The piston is given multiple functions: it serves as both the movable element for pressure detection and as the support structure for the movable electrode, eliminating the need for separate transmission components and reducing energy loss
2Reliability
If a high bias voltage is applied to the movable electrode to prevent pull-in, then reliability improves, but energy losses increase
Solution Approach 1:
The patent changes the mechanical parameter of the support structure by directly anchoring the movable electrode to the piston, which alters the electrical parameter (bias voltage requirement) and reduces energy loss while maintaining reliability
3Stability of the object's composition
If the movable electrode is anchored to the transmission device, then the structure is stable, but mechanical force transformation causes energy losses
Solution Approach 1:
The patent removes the intermediate transmission components (transmission arms and shafts) that cause force transformation and energy loss, while maintaining structural stability by directly anchoring the movable electrode to the piston
Solution Approach 2:
The patent merges the support function with the piston itself, combining the movable element and the electrode support into a single integrated structure, thereby eliminating energy loss in force transformation while maintaining stability
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 system enhances signal output by minimizing energy loss and reducing the risk of electrode failure, maintaining sensitivity and flexibility for dynamic pressure detection.
Implementation Method 1
the movable electrode 152 and the counter-electrode 153, 154 form armatures of one or more capacitors whose capacitance varies as a function of the displacement of the movable element 13
Implementation Method 2
an elastic device connected to the movable electrode 152 and configured to generate an elastic force which opposes the electrostatic force
Implementation Method 3
This pull-in phenomenon is caused by the electrostatic force, which tends to bring the movable electrode closer to the fixed electrode
Data Source
AI summary
An electromechanical system includes a frame; a movable element; a capacitive measurement or actuation system including a movable electrode and at least one fixed electrode, referred to as a counter-electrode, the movable electrode including a membrane and a membrane rigidifying structure; a device for transmitting movement between the movable element and the movable electrode, the transmission device being rotatably movable relative to the frame by a plurality of pivot hinges; and an elastic device connected to the movable electrode and configured to generate an elastic force which opposes movement of the movable electrode; the rigidifying structure of the movable electrode being secured to the transmission device and anchored to the transmission device at at least one part of the pivot hinges.