A Surface Acoustic Wave Pumped Lensless Microfluidic Imaging System for Flowing Cell Detection and Counting

Area of Science:

• Biomedical Engineering
• Microfluidics
• Optics

Background:

• Point-of-care diagnostics require miniaturization of bulky bioanalysis instruments.
• Lab-on-CMOS-chip technology offers a promising solution for miniaturization.
• Existing lensless systems often rely on external, bulky syringe pumps for fluid manipulation.

Purpose of the Study:

• To develop a miniaturized, lensless microfluidic imaging system for flowing cell detection and counting.
• To integrate a surface acoustic wave (SAW) pump directly onto a CMOS image sensor chip.
• To implement an efficient algorithm for continuous cell detection and counting.

Main Methods:

• Integration of a SAW pump onto a CMOS image sensor chip for microfluidic driving.
• Development of a temporal-differencing-based motion detection algorithm.
• Experimental validation using human bone marrow stromal cells in a microfluidic channel.

Main Results:

• The SAW pump successfully drove microfluidic flow at varying powers.
• The system maintained channel temperature below 40°C, ensuring cell viability.
• Automated detection and counting of flowing cells achieved a low statistical error rate of -6.53%.

Conclusions:

• The developed lab-on-CMOS-chip system offers a compact and efficient solution for cell detection and counting.
• SAW pump integration eliminates the need for external pumps, enhancing portability.
• The system demonstrates significant potential for point-of-care diagnostic applications.