Controlling drop movement on superhydrophobic surfaces is important in a number of technologies. For example, self-cleaning, superhydrophobic surfaces, microfluidics devices, and digital microfluidics can benefit from advances in developing non-wetting drops.

To move water-based droplets, magnetic fields have been applied across a surface, but droplet movement is typically retarded by the low contact angle between the droplet and the surface.

Researchers at Arizona State University have developed a magneto-fluidic device composed of a superhydrophobic surface and a fluid sample with magnetic particles coated with a passivating layer. Not only have the researchers shown controlled drop movement in a magnetic field, but also corrosion resistance against oxidizing agents.

The ability to control discrete fluid droplets at fixed locations offers new opportunities for the micro-scale control of protein chemistry, detection, and measurement.

Potential Applications

• Micro-scale fluidics
• Digital microfluidics
• Self-cleaning superhydrophobic surfaces

Benefits and Advantages

• Controlled movement of droplets in magnetic field
• Corrosion resistant magnetic particles
• Able to fix droplet position for measurement and detection

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For more information about the inventor(s) and their research, please see
Dr. Gust's departmental webpage
Dr. Gust's research webpage
Dr. Hayes' departmental webpage
Dr. Hayes' research webpage