Boron-Doped Tungsten Oxide Gas Sensor for Room-Temperature Acetone Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing acetone sensors require high operating temperatures, making them unsuitable for portable devices used in diagnosing and self-monitoring of outpatient conditions such as diabetes, which necessitates a sensor that can operate at ambient temperatures.
Innovation Solution
A gas sensor element comprising a polycrystalline n-type semiconductor material, specifically boron-doped epsilon or gamma phase tungsten oxide (WO3), with a co-catalyst like CeO2, that detects acetone by changes in resistivity at room temperature, and is fabricated using combustion synthesis and surface area enhancement techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high operating temperatures are used to increase electron movement across the band gap, then sensitivity of the semiconductor material is improved, but portability and ease of operation deteriorate due to power consumption and thermal management requirements
Solution Approach 1:
The patent changes the operating temperature parameter from high (300°C+) to ambient/room temperature, fundamentally altering the sensor's operational characteristics. This is achieved through material composition changes (n-type semiconductor with specific band gap properties) that enable sufficient electron excitation and sensitivity without requiring thermal energy input, thus resolving the contradiction between sensitivity and portability
Solution Approach 2:
The patent replaces the thermal field (heating mechanism) with an alternative detection mechanism that operates at ambient temperature. Instead of using thermal energy to excite electrons across the band gap, the sensor utilizes the inherent electrical properties of the n-type semiconductor material at room temperature, eliminating the need for heating elements and thermal management systems, thereby enabling portability
2Difficulty of detecting and measuring
If high operating temperatures are used to enhance electron movement, then detection capability is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent extracts and eliminates the heating subsystem from the sensor design. By developing an n-type semiconductor material that provides sufficient detection capability at ambient temperature, the patent removes the need for temperature control systems, thermal insulation, power management for heating, and associated complexity, thereby simplifying the overall device architecture while maintaining detection capability
3Measurement precision
If high operating temperatures are used to provide energy for electron movement, then sensitivity is improved, but energy consumption increases
Solution Approach 1:
The patent fundamentally changes the energy parameter by operating at ambient temperature instead of high temperature. The n-type semiconductor material is specifically selected or engineered to have appropriate band gap energy that allows sufficient electron excitation and charge carrier generation at room temperature, eliminating the need for continuous thermal energy input while maintaining sensitivity for detecting changes in electron movement in response to target analytes
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 solution enables the detection of acetone at room temperature, enhancing sensitivity and operational efficiency for portable devices, allowing for effective diagnosis and monitoring of conditions like diabetes without the need for high-temperature operation.
Implementation Method 1
the presence of acetone is detected by a change in resistivity across the sensor
Implementation Method 2
combustion synthesizing a boron doped epsilon or gamma phase WO3 semiconductor
Data Source
AI summary
Described herein are sensor elements for detecting the presence of organic materials comprising a boron doped n-type semiconductor material with decrease in resistivity upon organic materials exposure with increase in resistivity upon organic materials exposure.