Micromechanical Electric Field Sensor with Segmented Electrodes
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Solution Overview
Problem
Existing electric field measurement devices, such as field mills and electro-optical sensors, face challenges including distortion of the electric field, large size, and temperature sensitivity, particularly when measuring static or quasistatic electric fields.
Innovation Solution
A micromechanical structure with a conductive frame and movable portion, connected elastically, that is designed to detect electric field components without grounding, allowing for precise measurement of static or quasistatic electric fields without distorting the field, and is temperature-stable due to well-defined mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If field mills are used to measure electric fields, then measurement capability is achieved, but the device size becomes large and unwieldy
Solution Approach 1:
The sensor electrode is divided into multiple segments arranged in a comb-like structure, allowing the measurement function to be distributed across smaller components rather than requiring a single large electrode
Solution Approach 2:
The patent transitions from the traditional rotating impeller mechanism to a comb-like structure where measurement occurs along the length of multiple fingers, effectively utilizing dimensional redistribution to reduce overall device footprint
2Reliability
If grounding is provided for field mill components, then electrical stability is improved, but the electric field to be measured is distorted
Solution Approach 1:
The grounding connection is completely removed from the sensor electrode, extracting the harmful grounding element from the system while maintaining measurement functionality through capacitive coupling alone
Solution Approach 2:
The patent introduces a dielectric layer as an intermediary between the sensor electrode and the environment, allowing capacitive coupling for measurement while preventing direct electrical connection that would cause field distortion
3Object-generated harmful factors
If electro-optical sensors are used for electric field measurement, then no grounding is required and field distortion is reduced, but temperature stability deteriorates due to pyroelectric effects
Solution Approach 1:
The patent uses homogeneous dielectric materials with matched thermal expansion coefficients for all insulating components, ensuring uniform thermal behavior and minimizing temperature-induced measurement drift
Solution Approach 2:
The patent carefully selects dielectric materials with specific electrical and thermal parameters, including breakdown voltage, permittivity, and thermal expansion coefficient, to optimize both electrical performance and temperature stability
4Volume of moving object
If micromechanical structures are miniaturized, then device size is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The comb-like sensor structure is integrated with the substrate as a single monolithic component, merging multiple elements into one fabrication process to eliminate alignment and assembly tolerances
Solution Approach 2:
The substrate serves multiple functions simultaneously: mechanical support, electrical insulation, and structural framework, reducing the number of separate components and their associated manufacturing tolerances
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 device provides accurate, non-distorting measurements of static or quasistatic electric fields with high sensitivity and temperature stability, enabling compact and miniaturized designs for various applications, including weather monitoring and occupational safety.
Implementation Method 1
the micromechanical structure is designed so that at an arrangement of the micromechanical structure in the electric field with a first field strength component parallel to the first direction uneven zero an electrical polarization of the micromechanical Structure, which results in a movable portion first force component parallel to the first direction
Implementation Method 2
the movable portion with the frame portion is electrically conductive and mechanically elastically connected and movable relative to the frame portion
Data Source
Figure 1~2
Figure 3~5
Figure 6~8
AI summary
The invention relates to a device for measuring an electric field (E), the device comprising a micromechanical structure (1) made of a material that is electrically conductive at an operating temperature, wherein the micromechanical structure (1) has a frame portion (2) and a movable portion (3); the movable portion (3) is electrically conductively and mechanically elastically connected to the frame portion (2) and can be moved relative to the frame portion (2); the micromechanical structure (1) is designed in such a way that, when the micromechanical structure (1) is arranged in the electric field (E), an electrical polarization of the micromechanical structure (1) occurs by means of a first field intensity component (Ex) not equal to zero, which first field intensity component is parallel to a first direction (x), said electrical polarization causing a first force component (Fx) acting on the movable portion, which first force component is parallel to the first direction (x), and a change in the spatial arrangement of the movable portion (3) relative to the frame portion (2), which change is dependent on the first force component (Fx); and wherein detection means (9, 11, 15, 16) are provided for determining said change.