CMOS FET Biosensor Circuit for Low-Power Charge Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional techniques for detecting biological molecules, such as fluorescence or radioactive labeling, are labor-intensive and costly, limiting their effectiveness in disease diagnosis and treatment.

Innovation Solution

An apparatus and method using field-effect transistors (FETs) to automate the detection of biomolecules through an inverting gain amplifier circuit, where the gate of a first FET senses electric charge, and the output provides a measurement to identify the material, leveraging CMOS technology for efficient and cost-effective biomolecule detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional techniques (fluorescence or radioactive labeling) are used to detect biomolecules, then detection capability is achieved, but labor intensity and cost increase significantly

Engineering Contradiction:
Improvebiomolecule detection capabilityVSAvoidlabor intensity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces manual mechanical operations (labor-intensive conventional techniques) with an automated electronic system based on FET sensors and CMOS circuits. The FET gate automatically detects biomolecule binding events through electrical signal changes, eliminating the need for manual fluorescence or radioactive labeling operations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The FET-based sensor system performs self-detection without requiring external manual intervention. The sensor's gate automatically responds to biomolecule binding by changing its electrical properties, and the CMOS circuitry automatically converts these changes into readable signals, enabling autonomous detection.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If conventional techniques (fluorescence or radioactive labeling) are used to detect biomolecules, then detection capability is achieved, but cost increases significantly

Engineering Contradiction:
Improvebiomolecule detection capabilityVSAvoidcost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent employs inexpensive FET sensors that can be fabricated using standard CMOS technology. These sensors replace expensive radioactive or fluorescent labels, providing a cost-effective detection mechanism that does not require costly reagents or specialized materials.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention substitutes expensive conventional detection methods with an electronic detection system based on FET sensors and CMOS circuits. This electronic approach eliminates the need for costly fluorescence or radioactive labeling reagents and equipment.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If FET-based automated detection is implemented, then labor intensity and cost are reduced, but sensitivity and measurement precision must be maintained or improved

Engineering Contradiction:
Improveautomation levelVSAvoiddetection sensitivity
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent utilizes changes in electrical parameters (gate voltage, drain current) of the FET sensor to detect biomolecule binding. By monitoring these electrical parameter changes, the system achieves high sensitivity and precision while maintaining automation. The CMOS circuitry amplifies and processes these subtle electrical signals to ensure accurate detection.

Inventive Principle:
Principle #35Parameter changes

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 FET-based system enhances sensitivity and reduces costs by automating biomolecule detection, allowing for efficient and cost-effective identification of biomolecules, with the ability to confirm readings and optimize sensor cells for specific biomolecules, thereby improving disease diagnosis and treatment.

Implementation Method 1

a gate of the first FET is configured to sense the electric charge

Methodology Applied
Scientific EffectElectrostatic interaction: Electrostatics

Data Source

PatentEP2521909B1Ultra low-power CMOS based bio-sensor circuit
Publication Date: 2018.11.07 INTERNATIONAL BUSINESS MACHINE CORPORATION
  • EP2521909B1 patent drawingFigure 1~2
  • EP2521909B1 patent drawingFigure 3~4
  • EP2521909B1 patent drawingFigure 5~6

AI summary

An apparatus configured to identify a material having an electric charge, the apparatus having: an inverting gain amplifier including a first field-effect transistor (FET) coupled to a second FET; wherein a gate of the first FET is configured to sense the electric charge and an output of the amplifier provides a measurement of the electric charge to identify the material.