OFET Gas Sensor Current Acquisition With Dual Detection Modes
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Solution Overview
Problem
Existing gas sensing technologies based on organic field effect transistors (OFETs) face challenges in achieving high sensitivity, selectivity, and stability for real-time monitoring of harmful gases, particularly in miniaturized forms and special environments, and require improved methods for accurate current detection and long-term energy supply.
Innovation Solution
A drain-gate voltage excitation and source-drain current acquisition system for gas-sensitive OFETs, comprising a microcontroller module, power supply management, voltage excitation, transimpedance amplifier, fully-differential low-side current detection, voltage acquisition, signal transmission, and array switching modules, which utilize weighted sum current detection methods and rapid switching technology to enhance accuracy and range of current detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional current detection methods are used for gas-sensitive OFETs, then the detection system is simple, but the measurement accuracy and detection range are insufficient
Solution Approach 1:
The patent divides the current detection function into two separate modules: a transimpedance amplifier (TIA) module for low-current detection and a fully-differential low-side current detection module for high-current detection. Each module is optimized for specific current ranges, allowing the system to achieve high measurement precision across different orders of magnitude while managing complexity through functional segmentation
Solution Approach 2:
The patent implements dynamic switching between different current detection methods based on the actual current magnitude. The microcontroller automatically selects the appropriate detection mode (TIA or low-side detection) and adjusts weighting factors in real-time, enabling the system to adapt to varying gas concentrations and maintain optimal measurement accuracy without requiring a fixed complex architecture
2Adaptability or versatility
If a single current detection method is used, then the system is simple, but the detection range is limited and overflow occurs
Solution Approach 1:
The patent employs dynamic detection mode switching where the microcontroller monitors current magnitude and automatically transitions between TIA mode (for low currents) and low-side detection mode (for high currents). This dynamic adaptation expands the detection range across multiple orders of magnitude while avoiding overflow, with the system intelligently selecting the appropriate detection pathway based on real-time conditions
Solution Approach 2:
The patent implements a weighted sum approach that combines results from both detection methods, using adjustable weighting factors to optimize the contribution of each method. This allows the system to utilize information from both TIA and low-side detection even when one method is primary, effectively expanding the usable detection range and providing redundancy without requiring a single overly complex detection circuit
3Productivity
If rapid switching technology is not used, then the system is simpler, but real-time monitoring capability is reduced
Solution Approach 1:
The patent implements periodic scanning of the OFET array with rapid switching between different sensors and detection modes. The microcontroller cycles through multiple sensors in the array, switching detection methods based on current magnitude, and aggregates results to provide real-time gas concentration monitoring. This periodic action enables comprehensive monitoring coverage while maintaining real-time response capability
Solution Approach 2:
The patent incorporates automatic mode selection and adaptive weighting adjustment where the system self-regulates without external intervention. The microcontroller automatically determines the appropriate detection mode based on measured current levels, dynamically adjusts weighting factors for optimal accuracy, and manages the switching between sensors and methods, reducing the need for complex external control circuitry while maintaining high productivity
Data Source
AI summary
The present disclosure provides a drain-gate voltage excitation and source-drain current acquisition system and method for gas-sensitive organic field effect transistors (OFETs). The system includes an acquisition device and a gas-sensitive OFET array. The device includes a microcontroller module, a power supply management module, a voltage excitation module, a voltage regulation module, a transimpedance amplifier (TIA) module, a fully-differential low-side current detection module, a voltage acquisition module, a signal transmission module and an array switching module. In the present disclosure, the real-time monitoring of various harmful gases and the performance testing of the gas-sensitive OFETs are realized. The device has two current detection modes, thereby not only stabilizing drain electric potentials, but also enabling drain-source currents to be measured with sufficient accuracy.