Graphene FET Sensor Arrays with Serpentine Source Routing
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Solution Overview
Problem
Traditional sensors face limitations in efficiently detecting and converting biological signals into electrical signals, particularly for nucleic acids, bacteria, and fungal agents, due to issues such as signal drift and low sensitivity.
Innovation Solution
A graphene-based FET sensor array is designed with a serpentine common source electrode, a separate gate layer, and a conductive cap to enhance signal detection, minimize silicon exposure, and reduce electrical drift, while using a multilevel resistive mask ROM for authentication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional sensors are used for detecting biological signals, then the device complexity is low, but the sensitivity and measurement precision are insufficient
Solution Approach 1:
The sensor array is divided into multiple independent sensor elements, each capable of detecting biological signals. This segmentation allows parallel processing of multiple samples or multiple detection channels, improving sensitivity and measurement precision while maintaining manageable device complexity through modular architecture
Solution Approach 2:
The patent employs graphene-based FETs as the core sensing element, utilizing the exceptional electrical properties of graphene (high electron mobility, high surface area to volume ratio) to achieve superior sensitivity. The composite structure combines graphene channel with gate electrodes and source/drain contacts to create a sensor array with enhanced detection capability
2Reliability
If traditional FET sensors are used, then the manufacturing process is simple, but signal drift occurs and stability is poor
Solution Approach 1:
The patent implements separate gate electrodes for each sensor element, allowing independent voltage control and compensation for each sensor. This local control enables correction of signal drift in individual sensors without affecting the entire array, improving stability while maintaining manufacturing feasibility through standardized fabrication processes
Solution Approach 2:
The sensor array incorporates reference sensors and compensation mechanisms that provide feedback signals to correct for drift and instability. By monitoring reference elements and comparing them with sensor outputs, the system can compensate for environmental variations and maintain stable measurements
3Measurement precision
If graphene-based FETs are used to improve sensitivity, then the measurement precision increases, but the device complexity increases
Solution Approach 1:
The graphene-based FET array is designed with universal functionality to detect multiple types of biological analytes (nucleic acids, proteins, cells) using the same sensor platform. The standardized sensor elements can be functionalized with different receptors or antibodies, allowing one device to perform multiple detection functions, thereby justifying the increased complexity through enhanced versatility
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 design improves sensitivity and stability of biological signal detection, allowing precise measurement of minute amounts of nucleic acids, bacteria, and fungal agents by maintaining consistent electrical signals and reducing signal drift.
Implementation Method 1
Since the charge carrier mobility of graphene is very high, the change of conductance with respect to the presence of charged molecules of a GFET sensor is extremely abrupt
Implementation Method 2
An electric field is applied at the gate terminal to measure the conductivity of a channel placed between source and drain
Data Source
AI summary
This disclosure describes a system for fabricating and method for using a graphene-based FET (GFET) sensor array. The GFET sensor array is fabricated on a silicon substrate and comprises an array of sensors, a plurality of drain terminals, a source terminal, and a gate terminal. Each drain terminal of the plurality of drain terminals is configured to be electrically connected to a sensor of the array of sensors. The source terminal is configured to be electrically connected, via a common line, to each sensor of the array of sensors. The common line traverses the array of sensors in a serpentine pattern.