A handheld plug-and-play microfluidic liquid handling automation platform for immunoassays

Area of Science:

• Biomedical Engineering
• Microfluidics
• Analytical Chemistry

Background:

• Lab-on-a-chip and microfluidics enhance immunoassay efficiency through miniaturization and automation.
• Current microfluidic systems often require large external equipment, hindering point-of-care (POC) applications.
• There is a need for portable, automated liquid handling solutions for decentralized diagnostics.

Purpose of the Study:

• To develop a fully automated, handheld microfluidic liquid handling platform.
• To enable plug-and-play operation for point-of-care diagnostic assays.
• To demonstrate the system's capability with a SARS-CoV-2 antibody immunoassay.

Main Methods:

• A handheld platform with a clamshell cartridge socket and miniature electro-pneumatic controller was designed.
• Valveless plastic cartridges were utilized for multi-reagent switching, metering, and timing control via electro-pneumatic pressure.
• A SARS-CoV-2 spike antibody fluorescent immunoassay (FIA) was performed on an acrylic cartridge.

Main Results:

• The system achieved automated, human-free liquid handling after sample introduction.
• The SARS-CoV-2 FIA demonstrated a limit of detection of 31.1 ng/mL, comparable to ELISA.
• The platform also functions as a 6-port pressure source for external microfluidic chips.
• The battery-powered system operates for 42 hours and has a compact footprint (16.5 × 10.5 × 7 cm, 801 g).

Conclusions:

• The developed handheld platform provides a versatile, automated solution for microfluidic liquid handling.
• Its plug-and-play design and portability are suitable for diverse POC and research applications.
• The system facilitates complex liquid manipulation for diagnostics, cell analysis, and biomanufacturing.