Integrated SAW Sensor Assembly for Passive Multi-Sensor Differentiation
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Solution Overview
Problem
Existing sensor technologies face challenges in efficiently measuring environmental conditions such as pressure and temperature without active power sources and in distinguishing between multiple sensors on a single substrate.
Innovation Solution
A sensor device incorporating a surface acoustic wave (SAW) sensor assembly with integrated conductive elements like antennas, circuitry, and interdigitated transducers on a piezoelectric substrate, which generates SAWs to measure environmental conditions passively and distinguishes between sensors through unique frequencies and signal modulations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple SAW sensors are deployed to measure environmental conditions, then measurement coverage is improved, but signal differentiation between sensors deteriorates
Solution Approach 1:
Each SAW sensor is equipped with a unique dielectric coating configuration (different materials, thicknesses, or patterns) that creates localized property variations. This enables each sensor to have distinct resonant frequencies and signal characteristics while maintaining the same basic sensor structure, allowing multiple sensors to operate simultaneously without signal confusion
Solution Approach 2:
The patent varies physical parameters of the dielectric coatings (material composition, thickness, spatial distribution) to tune the resonant frequencies of different SAW sensors. By changing these parameters, each sensor produces a unique signal signature that enables differentiation and identification of individual sensors in a multi-sensor array
2Ease of manufacture
If integrated sensor assembly is implemented, then manufacturing complexity is reduced, but component integration density increases
Solution Approach 1:
The patent integrates multiple functional components (SAW sensors, dielectric coatings, interdigitated transducers, and signal processing elements) onto a single substrate or wafer. This merging of components into an integrated sensor assembly reduces the number of separate manufacturing steps, eliminates alignment issues between discrete components, and simplifies the overall fabrication process while enabling high integration density through planar processing techniques
3Use of energy by moving object
If passive measurement is used, then energy consumption is reduced, but signal differentiation capability deteriorates
Solution Approach 1:
The SAW sensors operate passively by utilizing the piezoelectric properties of the substrate and the resonant characteristics of the dielectric coatings to generate and detect acoustic waves without requiring active electronic components or external power sources. The sensors self-generate signals through applied mechanical or electrical excitation and self-detect changes in resonant frequency caused by environmental conditions, enabling passive measurement while maintaining signal differentiation through unique coating configurations
Solution Approach 2:
Even in passive operation, each sensor's unique dielectric coating parameters (material, thickness, pattern) create distinct resonant frequency responses. These parameter variations enable signal differentiation without requiring active electronics, as the passive sensors naturally produce distinguishable signals based on their physical 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
Enables passive measurement of extreme environmental conditions and differentiation between multiple sensors on a single substrate, reducing manufacturing costs and complexity while improving sensor performance and applicability.
Implementation Method 1
The transduction from electrical energy to mechanical energy (in the form of SAWs) is accomplished through the use of piezoelectric materials. Piezoelectric materials are materials that have the ability to generate internal electrical charge from mechanical stress as well as internally generate mechanical strain in response to an applied electric field.
Implementation Method 2
Surface acoustic waves (SAWs) are sound waves that travel parallel to the surface of an elastic material. SAWs are used in an electronic devices, particularly RF/IF filters.
Data Source
AI summary
A method for fabricating a sensor device that includes an integrated sensor assembly having a surface acoustic wave (SAW) sensor disposed on a piezoelectric substrate. The SAW sensor is adapted to measure an environmental condition of an environment in response to an RF signal. The SAW sensor includes an interdigitated transducer (IDT) formed on a substrate having at least a layer of a piezoelectric material. The SAW sensor includes either one or more SAW reflectors of a second IDT formed on the piezoelectric material. The SAW sensor further includes an RF antenna, a matching circuit and a waveguide are formed on the piezoelectric material. The SAW sensor and the RF antenna are integrated with one another on the piezoelectric material.