Piezoelectric Electric Field Sensing with Frequency-Shift Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric field detectors are bulky, expensive, and energy-consuming, making them unsuitable for applications such as electrostatic field measurement on airplanes, drones, or satellites, and they often produce biased measurement results due to the implementation of electric fields to vibrate MEMS devices.
Innovation Solution
The development of an electric field detector using an electromechanical oscillator with a piezoelectric element that vibrates at an oscillation frequency, coupled with a frequency measurement device and an electric masking set. The electric masking set limits the exposed part of the piezoelectric element, allowing the electric field to modify the oscillation frequency, which is then measured to determine the electric field intensity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional electric field detectors with movable masks and electrodes are used, then measurement functionality is achieved, but the device becomes bulky, expensive and energy-consuming
Solution Approach 1:
The patent replaces the traditional mechanical/electrical detection system (movable masks, electrodes, current detectors) with a piezoelectric oscillator-based system. The piezoelectric element vibrates mechanically and its oscillation frequency changes in response to electric field variations, eliminating the need for complex mechanical masking and electrical current detection systems while maintaining measurement functionality.
Solution Approach 2:
The patent utilizes the piezoelectric effect where mechanical stress on the piezoelectric element changes its electrical properties, and conversely, electrical fields change its mechanical oscillation frequency. By measuring the frequency shift of the piezoelectric oscillator, the system detects electric field variations without requiring complex measurement circuits, thus reducing device complexity while preserving measurement precision.
2Volume of moving object
If MEMS devices are used to detect electric fields, then device size is reduced, but measurement bias is introduced due to electric field generation during vibration
Solution Approach 1:
The patent introduces an electrical masking assembly as an intermediary between the piezoelectric oscillator and the electric field to be measured. This masking assembly selectively blocks portions of the electric field from reaching the piezoelectric element, allowing the device to measure only specific field components while eliminating self-generated field interference. The masking assembly enables accurate measurements in a compact form factor by controlling field interaction rather than relying on complex shielding.
3Measurement precision
If high-resolution analog-to-digital converters are used to measure electrical charges, then measurement precision is improved, but cost and energy consumption increase significantly
Solution Approach 1:
The patent replaces the electrical charge measurement approach (requiring high-resolution ADCs) with a mechanical oscillation frequency measurement approach. The piezoelectric element's natural oscillation frequency shifts in response to electric field variations, and this frequency can be measured using simple frequency counters or phase-locked loops that consume minimal energy and cost very little, while maintaining high measurement precision.
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 solution provides a compact, inexpensive, and low-energy-consuming electric field detector with accurate and reliable measurement results, as it eliminates the need for generating electric fields that could introduce biases in the measurements.
Implementation Method 1
an electromechanical oscillator, at least a part of which is constituted by a piezoelectric element intended to vibrate at an oscillation frequency during use of the detector
Implementation Method 2
The electric field to be measured which acts on the exposed and variable part of piezoelectric element during use of the detector, produces a change in the oscillation frequency which is measured by the frequency measuring device
Data Source
Figure 1~5
Figure 2a~3
Figure 6a~6b
AI summary
An electric field detector (20) comprises an electromechanical oscillator, part of which is formed by a piezoelectric element (1), a frequency measurement device (4) which is coupled to the oscillator so as to measure the oscillating frequency, and an electrical masking assembly (5). The electrical masking assembly is arranged close to the piezoelectric element (1) such that, when using the detector, the piezoelectric element moves by vibrating in relation to the electrical masking assembly. A variable part of the piezoelectric element is thus exposed to the electric field to be measured. A modification of the oscillating frequency (f) then forms an electric field measurement result.