Metal Oxide Sensor Assemblies for Breath Analysis
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Solution Overview
Problem
Current sensor technologies for detecting low concentrations of specific gases in human breath, such as acetone in diabetic patients, lack sensitivity, selectivity, and durability, and are often invasive, expensive, and not suitable for home-based monitoring.
Innovation Solution
Development of metal oxide based sensor assemblies using dopant-free metal oxide films, specifically WOx and CeOx films, fabricated by Reactive Spray Deposition Technology (RSDT), which are porous, have amorphous phase boundaries, and are deposited on micro-electro-mechanical-system substrates with gold or platinum inter-digitated electrodes, enabling detection of gases like acetone, NO2, and NO with high sensitivity and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional sensor technologies are used for detecting low concentration gases in breath, then the detection can be performed, but the sensitivity is insufficient to detect low concentrations (down to 0.2 ppm)
Solution Approach 1:
The patent employs porous metal oxide films (WOx, CeOx) with controlled pore structures to increase the surface area available for gas adsorption. This porous structure enables higher sensitivity detection of low concentration gases while maintaining reliable and stable detection performance through the material's inherent properties
Solution Approach 2:
The patent uses composite metal oxide systems (WOx-CeOx) where two different metal oxides work synergistically. CeOx provides oxygen storage and release capabilities while WOx offers high sensitivity to specific gases, together achieving both high sensitivity and reliable detection
2Measurement precision
If conventional sensor technologies are used, then detection can be performed, but the selectivity for specific gases is insufficient
Solution Approach 1:
The patent modifies the local chemical properties of the metal oxide film surface through controlled synthesis conditions, creating specific active sites with tailored properties. This local quality enhancement provides high selectivity for target gases without requiring complex multi-component sensor structures
Solution Approach 2:
The patent optimizes synthesis parameters (temperature, composition ratios, deposition conditions) to control the film's crystalline structure, grain size, and surface chemistry. These parameter changes enable the material to inherently distinguish between different gases based on their unique adsorption and reaction characteristics
3Duration of action of stationary object
If conventional sensor technologies are used, then detection can be performed, but the durability and long-term stability are insufficient (up to 450 hours)
Solution Approach 1:
The patent develops thin film sensors that can be easily replaced or regenerated. The metal oxide films are designed to maintain stability for extended periods (up to 450 hours) and then can be replaced through simple processes, ensuring continuous reliable operation without requiring complex maintenance of durable components
Solution Approach 2:
The patent optimizes the metal oxide film composition and synthesis parameters to achieve optimal stability. By controlling the metal oxide ratios, crystalline phases, and surface properties, the sensors achieve enhanced long-term stability and resistance to degradation under operating conditions
4Measurement precision
If invasive testing methods are used for breath analysis, then accurate measurements can be obtained, but the ease of operation and patient comfort are reduced
Solution Approach 1:
The patent replaces invasive mechanical blood sampling with non-invasive breath collection. The metal oxide sensors directly detect gas-phase biomarkers in exhaled breath, eliminating the need for needles, blood draws, or complex sample preparation while maintaining diagnostic accuracy
Solution Approach 2:
The patent utilizes changes in electrical properties (analogous to color changes in optical detection) of the metal oxide films when they interact with target gases. This provides a simple, direct readout method that requires minimal sample preparation and is easy to operate
5Measurement precision
If expensive sensor technologies are used, then high performance can be achieved, but the cost-effectiveness for home monitoring is reduced
Solution Approach 1:
The patent employs thin film deposition techniques that use minimal amounts of metal oxide materials, significantly reducing material costs. The sensors are designed as cost-effective devices suitable for disposable or frequent replacement applications in home monitoring, achieving high performance without expensive components
Solution Approach 2:
The patent optimizes synthesis parameters to achieve high-performance films at lower processing temperatures and with simpler equipment requirements. This reduces manufacturing costs while maintaining detection performance, making the sensors economically viable for home-based monitoring applications
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 sensors demonstrate rapid response times, high sensitivity to low concentrations of gases (down to 0.2 ppm), long-term stability (up to 450 hours), and resistance to humidity, making them suitable for non-invasive, cost-effective, and portable breath analysis for multiple disease monitoring.
Implementation Method 1
Metal oxides have been used as sensing materials for gas sensors due to their high surface area to volume ratio, which enhances their sensitivity to gas molecules
Implementation Method 2
A flame based process for the synthesis of metal oxide based sensor assemblies is provided
Implementation Method 3
nanoparticles generated in the flame are then directly deposited on the substrate as a film
Data Source
AI summary
Improved sensor assemblies are provided. More particularly, the present disclosure provides improved and highly advantageous metal oxide based sensor assemblies configured to sense low concentration of specific gases, and related methods of use. The present disclosure provides improved physical forms of metal oxide films (e.g., WOx films, CeOx films). The exemplary metal oxide films can be fabricated by a Reactive Spray Deposition Technology (RSDT). The highly advantageous films/materials can be utilized in sensor assemblies to detect simple chemical components of the breath that correlate with human health conditions (e.g., the presence of acetone in diabetic patients). These films/materials demonstrate improved thermal stability under the sensor's operating conditions, as well as improved sensitivity to low concentration of the analyte, selectivity and quick responsiveness.