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Picoinjection of Microfluidic Drops Without Metal Electrodes
Published on: April 18, 2014
Low voltage picoliter droplet manipulation utilizing electrowetting-on-dielectric platforms.
Yan-You Lin1, Erin R F Welch, Richard B Fair
1Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA.
Sensors and Actuators. B, Chemical
|April 6, 2013
Summary
Researchers demonstrated picoliter droplet actuation using scaled electrowetting-on-dielectric (EWD) devices. Precise electrode scaling enables dispensing and splitting of small droplets, showing EWD technology has not reached its scaling limit with good sealing.
Area of Science:
- Microfluidics
- Nanotechnology
- Surface Science
Background:
- Electrowetting-on-dielectric (EWD) technology enables precise liquid manipulation.
- Scaling down EWD devices is crucial for miniaturized applications.
- Achieving reliable droplet dispensing at the picoliter scale presents challenges.
Purpose of the Study:
- To demonstrate picoliter droplet actuation on scaled EWD devices.
- To investigate the effect of electrode dimensional scaling on droplet volume and dispensing.
- To explore droplet splitting and manipulation capabilities in microfluidic systems.
Main Methods:
- Fabrication of EWD devices with 33 μm and 21 μm electrodes.
- Utilized stacked multi-layer insulators (Ta2O5, parylene C, CYTOP).
- Investigated droplet dispensing voltages and splitting using varying electrode sizes and SU8 gaskets.
Main Results:
- Successfully dispensed 12 pl and 5 pl droplets using scaled EWD devices.
- Demonstrated droplet splitting (12 pl to 6 pl) with 33 μm electrode devices.
- Achieved droplet manipulation with paramagnetic beads and protein solutions.
Conclusions:
- Dimensional scaling of EWD devices has not yet met limitations for picoliter droplet dispensing.
- Effective sealing of the EWD structure is critical for successful device operation.
- Optimized electrode design and gasket features facilitate droplet dispensing in scaled EWD systems.
