Masters of Microscopy

Microscopy, Microdroplets and Sustainability with Kazi Rabbi and Xiao Yan

Welcome to Masters of Microscopy: The People Behind the Lens, where we showcase and celebrate the individuals who are the heart of the Nikon Small World competitions. They are scientists, artists, researchers, educators and everyday curious individuals who uncover the fascinating microscopic world around us.

What does condensation have to do with sustainability? As it turns out, quite a bit. The winners’ of this year’s Nikon Small World in Motion competition are giving the world an inside look at the important role this everyday phenomenon has in creating a more energy-efficient future, while inspiring awe from the 2020 judging panel for its visual appeal.

Mr. Kazi Fazle Rabbi and Dr. Xiao Yan captured the video in their lab at University of Illinois at Urbana-Champaign (UIUC). The movie features micro-droplets (made of 80% water and 20% ethanol) coalescing on top of a functionalized surface (a surface that has been engineered to interact with its environment in response to defined triggers such as contact with water. Think water-proof materials used in a smart phone).

The droplets, spherical in shape, ripple as they coalesce on top of the highly superhydrophobic surface that was designed by Rabbi and Yan. Creating surfaces that trigger this type of reaction is one of the pair’s research goals – creating materials that increase condensation and coalescence could be used to engineer more energy efficient products. For example, if the material used in water pipes can better repel water, the pipes will not freeze over when the temperature drops. Then, it wouldn’t require the excess use of heat and energy in a building just to keep said pipes from freezing.

Rabbi and Yan’s video of micro-droplets coalescing won the 2020 Nikon Small World in Motion competition

Yan and Rabbi teamed up at UIUC’s Department of Mechanical Science and Engineering where Yan is a Post-Doc and Rabbi is pursuing his Ph.D. To capture the video, the pair used transmitted light microscopy. The biggest challenge, they said, was controlling the micro-droplet generation and growth. They had to use a frequency-controlled micro-droplet dispenser and a high-speed camera interfaced with a microscopic lens to accomplish the task – all while focusing on the perfect plane and maintaining perfect lighting. It was a two-person job.

Rabbi and Yan conduct many experiments to see how liquids react to the functionalized surfaces they have created, which is how they were able to capture this year’s top video.

“Much of our microscopy is focused on visualizing how liquid droplets or condensate droplets interact with such surfaces at micro scale.” Yan said. This visualization is no easy feat to capture. The surface the droplets in the video are reacting to is one of Rabbi and Yan’s own designs.

Rabbi is passionate about his research in sustainability. “I am from Bangladesh, and one of the major concerns my country has been facing is the depletion of natural resources. I grew up knowing the importance of sustainability. Since my undergraduate days, I have always wanted to work on development of energy efficient systems,” Rabbi shared.

Mr. Kazi Fazle Rabbi

Presently, his research is focused on trying to develop surfaces for energy efficient condensers and heat exchangers to reduce energy consumption in power plants, transportation, HVAC, and petroleum industries. He is also working to create surfaces that can instantly defrost. This is important for winter dominant areas where frosting is a major concern. “Imagine not having to wait to defrost your car’s windshield or not having transportation delays due to frosting on planes or railways,” Rabbi explained.

Dr. Xiao Yan conducting research in his lab.

Yan, too, is interested in sustainability. He is focused on micro-scale droplet dynamics, which is critical during energy transport and heat transfer such as condensation, frosting, and icing. “I enjoy this research because I’m very motivated by the goals of this type of science, but the science itself is so beautiful. We get to create some pretty amazing videos in this line of work.” Yan said.

Beyond sustainability, Yan’s work with micro-droplets can help other researchers better understand how COVID-19 is spread. “We know the virus spreads through droplets, so if we can better understand how droplets move, interact with the air, etc., we could potentially better control the spread,” said Yan.

When Rabbi is not working in his lab, he enjoys traveling and photography. Yan also has a taste for fine art, particularly calligraphy. The pair’s appreciation for art and aesthetic beauty helps them to capture microscopy videos that not are not only helpful visualizations of their research, but also visually stunning.

Rabbi on a trip to the Rocky Mountains in Colorado and Yan visiting Chicago.

Rabbi and Yan hope that their video inspires the public to appreciate the beauty and microscopic intricacies of everyday occurrences.

“The beauty of this video definitely catches attention, but I hope it makes people curious, I hope it’s educational and pushes people to want to learn more or to think about how the real world and the microscopic world interact,” said Yan.

“When we saw this video, we were fascinated by it because we were just trying to observe what would happen to the droplet and ended up creating something very cool.” Rabbi added. “That’s why I say to anyone interested in microscopy, be patient and focus on the research, you never know what you will see under the microscope.”

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