Fabrication of rigid microstructures with thiol-ene-based soft lithography for continuous-flow cell lysis

Area of Science:

• Microfluidics
• Biotechnology
• Materials Science

Background:

• Existing on-chip cell lysis methods require long residence times, hindering rapid, continuous-flow applications.
• Rigid silicon devices are complex to fabricate, while common polydimethylsiloxane (PDMS) devices lack rigidity and deform under pressure, impairing lysis efficiency.

Purpose of the Study:

• To develop a novel soft-lithography-based fabrication method for rigid microstructures.
• To introduce a simple bonding technique for creating continuous-flow cell lysis devices.
• To overcome the limitations of existing microfluidic cell lysis technologies.

Main Methods:

• Fabrication of microfluidic microstructures using off-stoichiometry thiol-ene (OSTE) polymer via soft-lithography replica molding.
• Utilizing a post-assembly cure for straightforward device bonding.
• Employing finite element simulations to analyze microstructure-generated energy dissipation.

Main Results:

• The OSTE microstructures generate an energy dissipation rate of approximately 10^7, sufficient for continuous-flow cell lysis.
• Achieved 85% lysis rate for highly deformable MDA-MB-231 breast cancer cells using the OSTE device.
• A comparable PDMS device achieved only a 40% lysis rate.

Conclusions:

• The OSTE-based microfluidic device enables efficient and rapid continuous-flow cell lysis.
• The developed fabrication and bonding technique offers a viable alternative to existing methods for microfluidic cell lysis devices.
• This advancement facilitates faster and more effective cell lysis in microfluidic systems.