A programmable microfluidic platform for multisample injection, discretization, and droplet manipulation.

Area of Science:

• Microfluidics
• Biotechnology
• Chemical Engineering

Background:

• Microfluidic devices are crucial for precise control of small fluid volumes.
• Existing platforms often lack flexibility in sample handling and droplet manipulation.
• On-demand, programmable control over picoliter volumes is needed for advanced applications.

Purpose of the Study:

• To present a programmable microfluidic platform for on-demand sampling, compartmentalization, and manipulation of multiple aqueous volumes.
• To enable selective discretization of picoliter volumes from multiple sample inputs using a microtrap array.
• To demonstrate the platform's utility in biochemical synthesis and cell-based assays.

Main Methods:

• The platform integrates two interconnected chips with parallel T-junctions and multiplexed microvalves for programmable sample injection.
• Nanoliter volumes are transferred to a second chip with a microtrap array and membrane displacement actuators for picoliter droplet discretization.
• Two multiplexer designs were employed to reduce input signal requirements for injection and discretization.

Main Results:

• The system successfully achieved on-demand sampling, compartmentalization, and manipulation of multiple aqueous volumes.
• Selective discretization of picoliter volumes from multiple inputs was demonstrated using a random-access microtrap array.
• The platform facilitated the formation and manipulation of heterogeneous picoliter droplets, including cell encapsulation.

Conclusions:

• The developed microfluidic platform offers a versatile, programmable solution for droplet-based workflows.
• This technology provides flexible sample handling and precise manipulation of heterogeneous picoliter droplets.
• The platform is well-suited for applications in biochemical synthesis and cell-based assays requiring programmable, parallel, and multistep droplet processes.