Dual-Chamber FET Sensor Layout for Ionic Signal Noise Correction
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Solution Overview
Problem
Conventional FET-based biosensors struggle to separate signals from target biomolecules due to noise generated by surface reactions and pressure changes, leading to low sensitivity in detecting low concentrations of ionic materials.
Innovation Solution
A FET-based sensor system with a sensing chamber and a reference chamber, both containing FETs with the same structure and electrical characteristics, allows for signal correction by subtracting the current of reference FETs from sensing FETs, enabling effective separation of biomolecule signals from noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional FET-based biosensors are used to detect ionic materials, then the detection process is simple, but the sensitivity is low due to inability to separate signals from noise
Solution Approach 1:
The sensor system is divided into multiple FETs with different gate electrode configurations (some with probe biomolecules, some without). This segmentation allows parallel measurement of both target-specific signals and noise signals, enabling effective signal separation and improving detection sensitivity while maintaining manageable device complexity
Solution Approach 2:
Reference FETs without probe biomolecules serve as intermediaries that measure only the noise signals (drift signals from surface reactions and pressure effects). These reference measurements act as a mediator to subtract and eliminate noise from the total signal, thereby improving measurement precision without significantly increasing device complexity
2Measurement precision
If two FETs with different structures are used in a single chamber, then signal correction is attempted, but the reference FET cannot properly correct sensing FET signals due to different surface materials
Solution Approach 1:
All FETs in the system use the same gate electrode material and structure, ensuring homogeneous surface properties. This homogeneity guarantees that all FETs respond identically to noise signals (pressure changes and surface reactions), making the reference FET measurements reliable for correcting sensing FET signals and improving both measurement precision and correction effectiveness
3Measurement precision
If a single FET is used in the sensor, then the device is simple, but it cannot separate target biomolecule signals from noise signals
Solution Approach 1:
The single FET is segmented into multiple parallel FETs with different functional configurations (sensing FETs with probe biomolecules and reference FETs without probes). This segmentation enables simultaneous measurement of target-specific signals and noise signals, achieving signal separation while keeping the overall device complexity low through integrated fabrication
Solution Approach 2:
Reference FETs are created as copies of sensing FETs but without probe biomolecules. These copies measure only the common noise signals, allowing the system to subtract noise from sensing measurements. This copying approach enables signal separation without requiring complex additional components, balancing measurement precision with device simplicity
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
This approach enhances the sensitivity of the sensor system, allowing for the detection of low concentrations of ionic materials, such as biomolecules, by accurately correcting for noise-related signal interference.
Implementation Method 1
a gate that is formed on the substrate to connect the source and the drain... measuring a change in current according to the binding of a target biomolecule to a surface of the gate electrode
Implementation Method 2
a sensing chamber including a reference electrode and a plurality of sensing FETs
Data Source
AI summary
Provided are a FET-based sensor for detecting an ionic material, an ionic material detecting device including the FET-based sensor, and a method of detecting an ionic material using the FET-based sensor. The FET-based sensor includes: a sensing chamber including a reference electrode and a plurality of sensing FETs; and a reference chamber including a reference electrode and a plurality of reference FETs. The method includes: flowing a first solution into and out of the sensing chamber and the reference chamber of the FET-based sensor; flowing a second solution expected to contain an ionic material into and out of the sensing chamber while continuously flowing the first solution into and out of the reference chamber; measuring a current in a channel region between the source and drain of each of the sensing and reference FETs; and correcting the current of the sensing FETs.