High-thermal-conductivity integrated EWOD chip for ultra-fast, low-cost pathogen detection

Area of Science:

• Biotechnology
• Microfluidics
• Molecular Diagnostics

Background:

• Electrowetting on dielectric (EWOD) offers precise droplet control for nucleic acid detection.
• Current EWOD applications are limited by high costs, poor PCR compatibility, and inefficient heat transfer.

Purpose of the Study:

• To develop a low-cost, integrated EWOD system for rapid, on-site nucleic acid detection.
• To address challenges in heat transfer, droplet manipulation, and bubble suppression in EWOD devices.

Main Methods:

• Fabrication of a carbon-doped polycarbonate chip using a hybrid screen printing-injection molding process for enhanced thermal conductivity.
• Integration of hydrophilic sites for droplet pinning and bubble suppression during PCR.
• Implementation of a three-stage PID temperature control strategy for system optimization.

Main Results:

• Achieved 45-cycle PCR amplification in 10 minutes.
• Enabled full-process pathogen detection (10^3 CFU/mL) within 30 minutes.
• Maintained component costs under $1.

Conclusions:

• Developed a rapid and cost-effective EWOD solution for on-site nucleic acid detection.
• Significantly advanced the practical application of EWOD technology in diagnostics.