Ultrasound-Enabled Spatial Multi-Droplet Manipulation on Slippery Surfaces

Area of Science:

• Microfluidics and Nanotechnology
• Biomedical Engineering
• Energy Harvesting

Background:

• Controllable droplet manipulation is vital for microfluidics, biomedicine, and energy harvesting.
• Synchronous control of multiple droplets on single or spatially separated surfaces remains a significant challenge.

Purpose of the Study:

• To develop a novel droplet ultrasonic bowl (DUB) for advanced multi-droplet manipulation.
• To enable programmable and contactless control of droplets on slippery liquid-infused surfaces.

Main Methods:

• Utilizing multiple twin-trap ultrasonic fields with dynamic quantity and position modulation.
• Implementing the DUB on monolayer and double-layer surfaces for droplet control.
• Demonstrating precise movement, synchronous position exchange, and simultaneous transport of multiple droplets.

Main Results:

• Achieved programmable manipulation of single and multiple droplets, including precise movement and synchronous position exchange.
• Successfully demonstrated synchronized manipulation of droplets on double-layer surfaces and steady control of pendant droplets.
• Showcased applications in intelligent droplet circuits, spatial chemical reactions, and obstacle avoidance.

Conclusions:

• The developed DUB offers a promising strategy for contactless multi-droplet manipulation.
• This technology significantly advances capabilities in microfluidic applications.
• The DUB system provides precise control for complex droplet operations.