Integrated sieving microstructures on microchannels for biological cell trapping and droplet formation

Area of Science:

• Materials Science and Engineering
• Microfluidics
• Biotechnology

Background:

• Microfabrication techniques are crucial for developing advanced microfluidic devices.
• Existing methods for creating microstructures can be complex and costly.
• The need for accessible and scalable methods for producing micro-sieving structures is growing.

Purpose of the Study:

• To develop a simple, single-step microfabrication method for creating constriction microstructures.
• To demonstrate the utility of these structures as microsieves for size-dependent applications.
• To enable the use of widely available printing industry equipment for microfabrication.

Main Methods:

• A single-step microfabrication process was employed on a printed circuit board (PCB) master.
• Etching time of two microchannels was precisely controlled to form constriction microstructures.
• Polydimethylsiloxane (PDMS) replicas of these structures were generated to create microsieves.

Main Results:

• Successfully fabricated constriction microstructures on a PCB master using a controlled etching process.
• Generated PDMS replicas exhibiting effective sieving microstructures (microsieves).
• Demonstrated the potential for size-dependent trapping of microspheres and biological cells.

Conclusions:

• The developed single-step method offers an accessible and scalable approach to microfabrication.
• The resulting microsieves are suitable for various applications, including particle/cell sorting and droplet microfluidics.
• This technique leverages existing printing industry technology for micro-device fabrication.