Protected Sensor FETs Using Enclosed Analyte Channels
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Solution Overview
Problem
Sensor field effect transistors (SFETs) are prone to electronic drift due to contact with ambient environment materials, which affects their calibration and measurement accuracy.
Innovation Solution
Implementing a partial fluid isolation of the analyte-receiving region and sense electrode from the ambient environment by using an enclosed analyte channel or a cover structure that can be permanent or soluble, reducing contact with contaminants and stabilizing the calibration of SFETs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the sense electrode and analyte-receiving region are exposed to the ambient environment, then the SFET can be easily manufactured and operated, but electronic drift occurs due to contact with environmental contaminants
Solution Approach 1:
The device is segmented into distinct functional regions: an enclosed analyte-receiving region for fluid contact and a protected sense electrode region. The enclosure physically separates the sense electrode from the ambient environment while maintaining electrical connectivity, thereby reducing electronic drift without completely isolating the sensing function.
Solution Approach 2:
An intermediate enclosed channel structure serves as a mediator between the analyte fluid and the sense electrode. This enclosure allows analyte contact with the electrode while blocking harmful environmental contaminants, acting as a protective interface that maintains both sensing capability and calibration stability.
2Measurement precision
If the SFET is calibrated at the point of use, then measurement accuracy can be maintained, but user convenience decreases due to required calibration procedures
Solution Approach 1:
The enclosure structure performs preliminary protection by preventing environmental contaminants from reaching the sense electrode before they can cause drift. This pre-protective measure maintains calibration stability over time, reducing or eliminating the need for on-site calibration procedures.
Solution Approach 2:
The enclosed structure provides self-service by automatically protecting the sense electrode from environmental contaminants without requiring user intervention. The physical barrier continuously maintains calibration stability, allowing the device to operate without periodic user calibration actions.
3Reliability
If the sense electrode is enclosed to protect from contaminants, then electronic drift is reduced, but device complexity increases
Solution Approach 1:
The device is segmented into distinct functional regions: an enclosed analyte-receiving region for fluid contact and a protected sense electrode region. The enclosure physically separates the sense electrode from the ambient environment while maintaining electrical connectivity, thereby reducing electronic drift without completely isolating the sensing function.
Solution Approach 2:
The enclosure may utilize thin-film or flexible membrane structures that provide contaminant protection while allowing analyte permeation. These thin-film enclosures minimize added structural complexity while effectively blocking harmful environmental contaminants from reaching the sense electrode.
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 decreases electronic drift and stabilizes the calibration of SFETs, enhancing their accuracy and reducing the need for frequent calibration, thereby improving measurement reliability.
Implementation Method 1
The microfluidic drive structure can include an electroosmotic drive structure. The electroosmotic drive structure can include a plurality of electrical lines. The plurality of electrical lines can be formed across the enclosed analyte channel.
Data Source
AI summary
Protected sensor field effect transistors (SFETs). The SFETs include a semiconductor substrate, a field effect transistor, and a sense electrode. The SFETs further include an analyte-receiving region that is supported by the semiconductor substrate, is in contact with the sense electrode, and is configured to receive an analyte fluid. The analyte-receiving region is at least partially enclosed. In some embodiments, the analyte-receiving region can be an enclosed analyte channel that extends between an analyte inlet and an analyte outlet. In these embodiments, the enclosed analyte channel extends such that the analyte inlet and the analyte outlet are spaced apart from the sense electrode. In some embodiments, the SFETs include a cover structure that at least partially encloses the analyte-receiving region and is formed from a cover material that is soluble within the analyte fluid. The methods include methods of manufacturing the SFETs.