Multispectral Optical Sensor Using Piezoelectric Acoustic Wave Frequency Shift
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Solution Overview
Problem
Current methods for detecting trace amounts of ultraviolet (UV) and visible light require advanced measurement circuits, leading to high costs and limited price competitiveness.
Innovation Solution
A multispectral optical sensor utilizing zinc oxide (ZnO), gallium nitride (GaN), or cadmium sulfide (CdS) nanoparticles to detect changes in frequency of acoustic waves, allowing for the measurement of UV and visible light intensity using a single sensor with improved sensitivity and reduced circuit complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If advanced measurement circuits are used to detect trace amounts of UV and visible light, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces complex electronic measurement circuits with a piezoelectric-based acoustic wave sensing system. The piezoelectric material converts light-induced changes directly into acoustic wave frequency changes, which can be measured by simple frequency counters rather than complex current measurement circuits. This substitution of the measurement mechanism resolves the contradiction by achieving high detection sensitivity through physical transduction rather than electronic amplification.
Solution Approach 2:
The patent changes the measurement parameter from current (which requires complex circuits for trace detection) to acoustic wave frequency (which can be measured precisely with simple electronics). The piezoelectric material transduces light intensity changes into frequency modulations of acoustic waves, allowing trace light detection through frequency measurement instead of current measurement, thereby reducing circuit complexity while maintaining measurement precision.
2Device complexity
If a single sensor is used to measure both UV and visible light, then device complexity is reduced, but measurement precision for each spectrum may deteriorate
Solution Approach 1:
The patent segments the sensing function by placing different sensing layers (with different spectral responses) on the same piezoelectric substrate. Each sensing layer is optimized for specific wavelength ranges (UV, visible), and the piezoelectric material transduces the combined effects into acoustic wave frequency changes. This segmentation allows a single sensor structure to maintain high measurement precision for different spectra through layered functional specialization.
Solution Approach 2:
The piezoelectric material serves as a universal transducer for multiple spectral ranges. Instead of using separate sensors for UV and visible light, the same piezoelectric-acoustic wave system can detect both spectra by utilizing the different spectral responses of the sensing layers. This multi-functionality reduces device complexity while maintaining measurement precision through the universal transduction mechanism.
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 sensor achieves enhanced sensitivity and price competitiveness by detecting changes in frequency, enabling effective measurement of UV and visible light intensity even at trace levels without the need for highly advanced measurement circuits.
Implementation Method 1
a piezoelectric material, a first sensing layer and a second sensing layer spaced apart from each other on the piezoelectric material
Implementation Method 2
When the negative electrode is irradiated with UV light from the outside, photoelectrons are emitted by the photoelectric effect on the surface of the negative electrode
Data Source
AI summary
A multispectral optical sensor is disclosed. In one embodiment, the multispectral optical sensor includes a piezoelectric material, a first sensing layer and a second sensing layer spaced apart from each other on the piezoelectric material and configured to change the propagation speed of the acoustic wave propagated through the piezoelectric material by receiving ultraviolet light and visible light, respectively. The multiple optical sensor further includes a first acoustic wave output part and a second acoustic wave output part disposed on the piezoelectric material respectively corresponding to the first and second sensing layers and configured to generate an electrical signal based on the changed acoustic wave. The multiple optical sensor measures the intensity of ultraviolet and visible light using a single sensor by detecting the change in frequency, and measures the frequency change in the acoustic wave using zinc oxide, gallium nitride), or cadmium sulfide nanoparticles.