Multilayer Electret Actuator for Compact Long-Stroke Motion
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Solution Overview
Problem
Conventional electric actuators face limitations due to complex structures, high costs, and insufficient actuation stroke, primarily due to material physical properties, which restrict their size and performance.
Innovation Solution
The actuator design incorporates multiple conducting layers and electret layers with opposite preset electric fields, allowing for a simple structure, low element costs, and adjustable sizes, while achieving a sufficient actuation distance through the alternation of these layers and application of driving voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional electric actuator structures are used, then the actuator can perform basic actuation functions, but the structure becomes complex and manufacturing cost increases
Solution Approach 1:
The actuator is divided into multiple identical units, each comprising an electret layer sandwiched between two conducting layers. These segmented units are arranged in series to achieve the required actuation stroke while maintaining simple individual unit structures that are easy to manufacture
Solution Approach 2:
The patent changes the physical state of the dielectric material by using electret material with permanent polarization instead of conventional dielectric materials. This parameter change enables the actuator to achieve sufficient actuation stroke with simpler structure and lower manufacturing cost
2Reliability
If conventional electric actuator structures are used, then the actuator can operate, but the manufacturing cost increases due to complex structure and material requirements
Solution Approach 1:
The patent uses multiple copies of the same simple unit structure (electret layer between two conducting layers) to build the complete actuator. This copying approach reduces manufacturing cost by using identical, easily fabricated components rather than complex unique structures
Solution Approach 2:
The electret layers can be made from relatively inexpensive materials such as electret film or electrostatically charged dielectric layers. These layers are designed to be replaceable and inexpensive to manufacture, reducing overall system cost
3Device complexity
If conventional dielectric materials are used, then the actuator structure can be simple, but the actuation stroke is insufficient due to material physical properties
Solution Approach 1:
The patent transitions from using thick dielectric layers (one-dimensional approach) to using multiple thin electret layers arranged in series (multi-dimensional approach). This allows the actuator to achieve sufficient total actuation stroke while keeping each individual layer thin and the overall structure simple
Solution Approach 2:
The total actuation stroke requirement is segmented into multiple smaller contributions from individual electret layers. Each layer provides a small actuation displacement, but the cumulative effect of multiple layers in series achieves the required total stroke while maintaining structural simplicity
4Volume of moving object
If the actuator size is limited, then the device can be compact, but the actuation distance becomes insufficient with conventional designs
Solution Approach 1:
The patent uses a multi-layer stacked configuration where multiple electret-conducting layer units are arranged in series along the actuation direction. This vertical stacking enables sufficient actuation distance to be achieved within a compact overall volume, as the actuation strokes of individual layers accumulate in series
Solution Approach 2:
The actuator employs a nested multi-layer structure where electret layers and conducting layers are interleaved in a compact stacked arrangement. This nesting allows maximum actuation distance to be achieved within minimum device volume by efficiently utilizing the available space
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 results in a cost-effective actuator with a simple structure that can achieve a substantial actuation distance, even within limited sizes, facilitating its application in various devices such as speakers and keyboard modules with improved responsiveness and reduced distortion.
Implementation Method 1
a plurality of electret layers (120a, 120b)... each electret layer (120a, 120b) includes a preset electric field E1, E2
Implementation Method 2
Directions of preset electric fields of the adjacent electret layers are opposite... receive a driving voltage
Data Source
AI summary
An actuator is provided, including a plurality of conducting layers and a plurality of electret layers. The electret layers are respectively sandwiched between the conducting layers, and form gaps between the conducting layers. Directions of preset electric fields of the adjacent electret layers are opposite, and the adjacent conducting layers are respectively electrically connected to a first voltage end and a second voltage end to receive a driving voltage.