Acoustic Wave Array Sensor for Liquid Phase Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing surface-launched acoustic wave sensors face limitations in liquid phase sensing due to energy leakage and difficulty in creating a physical interface between the fluid sample and the device surface, particularly for Rayleigh wave sensors, and require protective coatings over electrode regions, which complicates manufacturing and assembly.
Innovation Solution
The development of a layer-guided shear horizontal acoustic plate mode (LG-SH-APM) array device using thinned single crystal piezoelectric substrates with integrated microfluidic channels, where guiding layers are placed opposite the electrodes, allowing for simultaneous measurement of multiple parameters without protective coatings, and utilizing frequency diversity and coding for individual channel identification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If Rayleigh wave sensors are used for chemical sensing, then gas phase detection is achieved, but liquid phase sensing is limited due to energy leakage and damping
Solution Approach 1:
The patent changes the wave mode parameter from Rayleigh wave to Love wave to eliminate energy leakage into liquid. Love waves are confined to the surface and do not radiate energy into the liquid medium, enabling liquid phase sensing while maintaining gas phase capability.
Solution Approach 2:
The patent uses a composite structure with a piezoelectric substrate and a guiding layer with lower acoustic velocity. This composite configuration creates Love wave modes that are confined to the surface region, preventing energy leakage into the liquid while enabling chemical sensing in both liquid and vapor phases.
2Adaptability or versatility
If STW or SH-SAW devices are used, then liquid phase sensing is enabled, but complex interfaces and constrained fluid contact are required
Solution Approach 1:
The patent extracts the sensing function to the surface of the device where the acoustic wave propagates. The analyte interacts directly with the sensor surface without requiring complex fluid containment interfaces, simplifying the overall device structure while enabling liquid phase sensing.
3Productivity
If arrays of multiple acoustic wave sensors are used for simultaneous measurement, then multiple parameters can be detected, but identification and differentiation of individual sensor responses becomes difficult
Solution Approach 1:
The patent introduces asymmetry in the form of unique frequency offsets for each sensor element in the array. This frequency diversity allows each sensor's response to be uniquely identified and differentiated, preventing information loss while enabling simultaneous multi-parameter measurement.
Solution Approach 2:
The patent assigns unique frequency codes to each sensor element in advance, before the measurement process. This preliminary coding enables straightforward identification and differentiation of individual sensor responses during simultaneous multi-parameter detection without requiring complex post-processing.
4Measurement precision
If conventional acoustic wave sensors are used, then basic sensing is achieved, but sensitivity is limited compared to LG-SH-APM devices
Solution Approach 1:
The patent changes the acoustic wave mode parameter to LG-SH-APM (layer-guided shear horizontal acoustic plate mode), which provides enhanced sensitivity through stronger interaction between the acoustic wave and the sensing layer. This parameter change achieves over an order of magnitude sensitivity improvement while maintaining practical device structure.
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 approach enhances sensor sensitivity by over an order of magnitude compared to conventional devices, enables simultaneous measurement of multiple parameters, and simplifies manufacturing and assembly, making it suitable for chemical and biological sensing in both liquid and vapor phases.
Implementation Method 1
acoustic wave array sensor device... surface acoustic wave transducer... surface acoustic wave reflector... acoustic tracks of the surface acoustic wave device
Implementation Method 2
layer-guided shear horizontal acoustic plate mode (LG-SH-APM) array device... The sensor material layer has a shear acoustic wave speed lower than a shear acoustic wave speed in the substrate
Implementation Method 3
thinned single crystal piezoelectric substrates... surface acoustic wave transducer... surface acoustic wave reflector
Data Source
AI summary
An acoustic wave sensor array device is provided for the detection, identification, and quantification of chemicals and biological elements dispersed in fluids. The sensor array device is capable of the simultaneous characterization of a fluid for multiple analytes of interest. A substrate has a plurality of channels formed therein and a sensor material layer applied in a bottom of the channels. The sensor material layer has a shear acoustic wave speed lower than a shear acoustic wave speed in said substrate. The channels may have the same material in each channel or different materials in at least two of the channels. A surface acoustic wave transducer and at least one surface acoustic wave reflector, or at least two transducers is formed on a surface of the substrate opposite the channels at a portion of the substrate that is thinned by the channels, so that the acoustic tracks of the surface acoustic wave device extend along the channels. The response of the surface acoustic wave depends on the response of the sensor material to a sensed fluid supplied to the channels.