High-precision modular microfluidics by micromilling of interlocking injection-molded blocks.

Area of Science:

• Microfluidics
• Mechanical Engineering
• Materials Science

Background:

• Microfluidic system development is limited by infrastructure, expertise, and time.
• 3D printing of microfluidics faces challenges in achieving necessary feature size, smoothness, and optical properties.

Purpose of the Study:

• To present a novel approach for designing and constructing high-precision, modular microfluidic systems.
• To overcome limitations of existing microfluidic fabrication methods.

Main Methods:

• Utilizing standard injection-molded blocks modified with micromilling.
• Employing elastically averaged contacts for assembly and O-ring seals for fluidic connections.
• Achieving channel dimensions as small as 50 μm depth and 150 μm width with high sealing reliability (>99.9%).

Main Results:

• Demonstrated droplet generation systems with rates >9000 min⁻¹ and coefficient of variation <3%.
• Integrated optical sensors and reconfigurable interfaces with glass microfluidic devices and imaging hardware.
• Achieved mechanical locating repeatability of ~1 μm and fluidic pressure resistance >400 kPa.

Conclusions:

• The modular block-based microfluidic system offers a cost-effective, widely available platform for research and education.
• This approach surpasses the dimensional quality of FDM and SLA 3D printed microfluidics.
• Enables easier construction and reconfiguration of complex microfluidic experiments.