A Hybrid Microfluidic/CMOS Capacitive Sensor Dedicated to Lab-on-Chip Applications.

Area of Science:

• Microfluidics
• Integrated Circuit Design
• Sensor Technology

Background:

• Lab-on-chips (LoCs) require highly integrated sensing solutions.
• Capacitive sensors offer potential for miniaturization and high sensitivity.
• Integrating microfluidics with CMOS circuitry presents fabrication challenges.

Purpose of the Study:

• To present a hybrid microfluidic/integrated circuit capacitive sensor for highly integrated lab-on-chips.
• To demonstrate the design and implementation of a charge-based capacitive sensor array in a 0.18-μm CMOS process.
• To integrate the sensor chip with a microfluidic channel using direct-write microfluidic fabrication process (DWFP).

Main Methods:

• Design and fabrication of a capacitive sensor array using 0.18-μm CMOS technology.
• Integration of the CMOS sensor chip with microfluidic channels fabricated via DWFP.
• Experimental validation using four chemical solutions with known dielectric constants.

Main Results:

• A highly sensitive CMOS capacitive sensor with a sensitivity of 530 mV/fF was achieved.
• Successful integration of microfluidic channels with the CMOS sensor chip.
• Demonstration of sensor functionality with different chemical solutions.

Conclusions:

• The hybrid microfluidic/CMOS capacitive sensor is a viable and sensitive solution for lab-on-chip applications.
• The combination of CMOS technology and DWFP offers a low-complexity approach for LoC development.
• The proposed sensor system shows significant promise for future microfluidic diagnostic and analytical systems.