Maximizing fluid delivered by bubble-free electroosmotic pump with optimum pulse voltage waveform

Area of Science:

• Microfluidics
• Electrochemistry
• Fluid Dynamics

Background:

• Faradaic reactions at electrodes limit high electric field electroosmotic (EO) flow in microfluidic pumps.
• Gas generation from these reactions reduces pump efficiency and performance.
• Optimizing parameters like voltage, fluid, and pulse duration is crucial for high current density EO pumping.

Purpose of the Study:

• To develop a novel numerical model for predicting gas generation during EO pumping.
• To optimize pulse voltage waveforms for enhanced EO pump performance.
• To enable higher current densities than previously reported in EO pumping.

Main Methods:

• A novel numerical model was developed to predict the onset of gas generation.
• Optimized pulse voltage waveforms were calculated using theoretical models.
• Experimental measurements of fluid volume displaced and flow rate were used to validate the model.

Main Results:

• The numerical model successfully predicts the onset of gas generation.
• Optimized pulse voltage waveforms allow for delayed gas generation.
• Higher current densities were achieved, leading to improved EO pumping efficiency.
• Experimental results confirmed the effectiveness of the optimized waveforms.

Conclusions:

• The developed numerical model and optimized pulse voltage waveforms effectively mitigate gas generation in EO pumping.
• This approach allows for significantly higher current densities, enhancing microfluidic pump performance.
• The findings provide a pathway for more efficient and effective microfluidic devices.