Graphene Varactor Analyte Sensing via CDC
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Solution Overview
Problem
Measuring chemical analytes, such as volatile organic compounds, in a clinically practical manner remains technically challenging due to the limitations of existing measurement systems.
Innovation Solution
A system comprising a capacitance to digital converter (CDC) and multiple graphene varactors, where the CDC measures capacitance over a range of DC bias voltages, and a multiplexor selectively provides electrical communication between the CDC and the graphene varactors, enabling rapid and accurate measurement of analyte presence.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional measurement systems are used to detect analytes, then the system structure is simple, but the measurement precision and detection accuracy are insufficient
Solution Approach 1:
The system segments the measurement task by using multiple graphene varactors, each functionalized to detect specific analytes (acetone, ethanol, isopropyl alcohol). This segmentation allows parallel detection of multiple analytes with high precision while maintaining manageable system complexity through modular architecture
Solution Approach 2:
The CDC device serves multiple functions: it provides excitation signals to the graphene varactors, measures their capacitance values, and processes the signals to generate analytical data. This multi-functionality improves measurement precision without proportionally increasing system complexity
2Productivity
If existing sensing methods are used, then the device complexity is low, but the productivity and data richness are limited
Solution Approach 1:
The system continuously measures capacitance values of multiple graphene varactors across different bias voltages, generating rich datasets in real-time. This continuous measurement approach significantly improves productivity and data richness compared to discrete sampling methods
Solution Approach 2:
The system adds measurement dimensions by varying bias voltages and measuring capacitance responses across multiple graphene varactors simultaneously. This multi-dimensional approach enriches the dataset without linearly increasing system complexity
3Measurement precision
If capacitance measurements are taken over multiple DC bias voltages, then the measurement precision and diagnostic information increase, but the measurement time and complexity increase
Solution Approach 1:
The system applies periodic excitation signals at different bias voltages to the graphene varactors and measures capacitance responses in a systematic sequence. This periodic measurement approach maintains high precision while optimizing measurement time through efficient signal cycling
Solution Approach 2:
The system pre-establishes capacitance-voltage characteristics by measuring at multiple bias voltages before actual analyte detection. This preliminary characterization improves measurement precision and enables faster real-time detection by reducing the need for repeated full-sweep measurements
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 system allows for precise and quick detection of various analytes in a single sample, generating a rich data set that can provide valuable diagnostic information, overcoming the limitations of existing systems.
Implementation Method 1
measuring the capacitance of the graphene varactors in response to an excitation signal over a plurality of DC bias voltages
Data Source
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AI summary
Embodiments herein relate to systems and devices for measuring analyte presence on graphene varactors, which can be used for analyte sensing in physiological gas samples. In an embodiment, a system for measuring analyte presence on a graphene varactor is 5 included having a capacitance to digital converter (CDC) and a graphene varactor. The CDC can be in electrical communication with the graphene varactor and can be configured to measure the capacitance of the graphene varactor in response to an excitation signal over a plurality of DC bias voltages. Other embodiments are also included herein.