A Hybrid Microfluidic Electronic Sensing Platform for Life Science Applications.

Area of Science:

• Microfluidics
• Electronic Sensors
• Semiconductor Devices

Background:

• Life science applications require precise and reliable sensing platforms.
• Existing sensors may lack the sensitivity or integration capabilities for complex biological and chemical analyses.
• Hybrid approaches combining microfluidics and electronic sensing offer potential for enhanced performance.

Purpose of the Study:

• To present a novel hybrid microfluidic electronic sensing platform.
• To design and implement an Open-Gate Junction Field-Effect Transistor (OG-JFET) sensor integrated with a microfluidic structure.
• To demonstrate the platform's functionality and applicability for chemical sensing, specifically pH variation.

Main Methods:

• Fabrication of an OG-JFET sensor with a large sensing area (0.7 mm²) using a foundry process.
• Integration of a polydimethylsiloxane (PDMS) microfluidic structure with the OG-JFET chip.
• Characterization of sensor performance using chemical solutions with varying pH values and mathematical modeling of charge sensitivity.

Main Results:

• The OG-JFET sensor demonstrated controllable gain via a back-gate voltage.
• Maximum transconductance gain reached ~1 mA/V at Vgs = 0 and Vds = 5.
• Sensitivity increased from ~40 mV/pH to ~55 mV/pH with back-gate voltage variation from 1.0 V to 0.0 V.

Conclusions:

• The proposed hybrid microfluidic OG-JFET sensor is a reliable and high-precision platform.
• The sensor is suitable for diverse life science and industrial applications.
• The integration of microfluidics and advanced FETs enables enhanced sample delivery and controlled sensing.