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High Speed Droplet-based Delivery System for Passive Pumping in Microfluidic Devices
Published on: September 2, 2009
Liquid DEP actuation and precision dispensing of variable volume droplets
Ravi Prakash1, Reginald Paul, Karan V I S Kaler
1Department of Electrical and Computer Engineering, University of Calgary, Calgary, AB, Canada. rprakash@ucalgary.ca
Lab on a Chip
|September 24, 2010
Summary
Precision microfluidic droplet dispensing is achieved using a tapered electrode structure and liquid dielectrophoresis (L-DEP). This method allows controlled, variable volume droplet generation, overcoming limitations of existing techniques.
Area of Science:
- Microfluidics
- Lab-On-a-Chip Technology
- Biotechnology
Background:
- Droplet-based microfluidic systems offer significant potential for Lab-On-a-Chip (LOC) applications.
- Precise control over droplet volume, concentration, and dispensing is crucial for realizing the full benefits of microfluidic technology.
Purpose of the Study:
- To demonstrate rapid and controlled microactuation and dispensing of variable volume droplets using a coplanar tapered electrode structure.
- To develop a generalized numerical model for tapered actuation schemes to explain experimental observations.
- To show proactive control over droplet density, overcoming Rayleigh's instability limitations.
Main Methods:
- Utilizing liquid dielectrophoresis (L-DEP) with a coplanar tapered electrode structure for droplet actuation.
- Developing and applying a generalized numerical model to analyze the transient behavior of tapered liquid jets.
- Implementing electrode structures with bumps and pinches to control droplet density.
Main Results:
- Demonstrated rapid and controlled dispensing of variable volume droplets in the nanolitre to picolitre range.
- Developed a numerical model that accurately accounts for experimental observations in tapered actuation.
- Showed that droplet density can be proactively controlled, overcoming Rayleigh's instability criterion.
Conclusions:
- The proposed L-DEP based droplet dispensing scheme offers superior control over droplet size and spacing compared to existing methods.
- The developed tapered electrode structure and numerical model enable precise manipulation of droplet characteristics.
- This technology advances microfluidic capabilities for LOC applications requiring variable volume and density droplet generation.
