Nanowire Oxide Oxygen Sensor for Fast Low-Temperature Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current oxygen gas sensors, including those with solid electrolytes and resistance-type oxide semiconductors, face challenges in sensitivity and response time, particularly at lower operating temperatures, and there is a lack of verification for hydrogen gas sensors' characteristics such as response speed and sensitivity to oxygen gas.
Innovation Solution
A gas sensor design combining a nanowire made of specific metals like platinum with an oxide layer of high-resistance semiconductors, creating two conduction paths for oxygen vacancies and electrons, enhancing response speed and sensitivity to oxygen gas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If oxygen gas sensors with solid electrolytes are used, then the sensor can detect oxygen gas, but the response time is slow (several tens of seconds) and sensitivity is insufficient
Solution Approach 1:
The patent combines a nanowire made of a specific metal (platinum, palladium, rhodium, ruthenium, osmium, or iridium) with an oxide layer made of a high-resistance semiconductor (such as zinc oxide, tin oxide, or cerium oxide). This composite structure creates two conduction paths: one through the nanowire and another through the oxide layer, enabling fast response and high sensitivity to oxygen gas without requiring high operating temperatures or reference gases.
2Loss of time
If resistance-type oxygen gas sensors using oxide semiconductors are used at very high temperatures (900°C or 600°C), then the response time is fast (10 seconds or less), but the operating temperature requirement is excessive for many applications
Solution Approach 1:
The patent changes the material parameters by using a nanowire-oxide composite structure with specific material combinations (metal nanowire + high-resistance semiconductor oxide). This allows the sensor to achieve fast response times at relatively low operating temperatures (around 300°C or lower), eliminating the need for very high temperatures while maintaining fast response characteristics.
3Temperature
If resistance-type oxygen gas sensors using oxide semiconductors are used at relatively low temperatures (around 300°C), then the operating temperature is suitable, but the response time becomes very slow (several hundred seconds or longer)
Solution Approach 1:
The patent uses a composite structure of metal nanowire and high-resistance semiconductor oxide that creates dual conduction paths. This composite material system enables the sensor to maintain fast response times even at relatively low operating temperatures (around 300°C), resolving the trade-off between operating temperature and response speed.
4Adaptability or versatility
If a platinum nanowire is used to detect hydrogen gas, then hydrogen detection is achieved, but there is no verification of response speed or sensitivity to oxygen gas
Solution Approach 1:
The patent enhances the versatility of the nanowire sensor by combining it with an oxide layer that enables the detection of multiple gas types including oxygen, hydrogen, and carbon monoxide. The oxide layer acts as a catalyst support and provides additional conduction paths, making the sensor universally applicable for detecting various gases with high sensitivity and fast response times.
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 gas sensor achieves fast response and high sensitivity to oxygen gas, capable of detecting oxygen even at low concentrations and low operating temperatures, with response and recovery times significantly improved.
Implementation Method 1
creates, in addition to a first conduction path where carriers (such as oxygen vacancies and electrons) pass through the nanowire, a second conduction path where carriers (such as oxygen vacancies and electrons) are injected from the nanowire into the oxide layer, travel through the oxide layer, and return to the nanowire
Data Source
AI summary
To provide a gas sensor with fast response and high sensitivity to oxygen gas. Disclosed is a gas sensor 100 including: a substrate 10; a first pad electrode 12A and a second pad electrode 12B; a nanowire 14 made of a specific metal; and an oxide layer 16 made of a high-resistance semiconductor that is an oxide of a metal different from a metal constituting the nanowire 14. The first pad electrode 12A and the second pad electrode 12B are formed on or above the substrate 10. The nanowire 14 connects the first pad electrode 12A and the second pad electrode 12B and is formed on or above the substrate 10.The oxide layer 16 is formed in contact with the nanowire 14. This contact between the nanowire 14 and the oxide layer 16 provides fast response and high sensitivity to oxygen gas.