Science With a Smile

The choice of career path—from teacher to musician to engineer—often results from experiences during one’s formative years. For children born after 1985, it’s likely a certain bow-tied, rumple-haired figure wearing a blue lab coat figured prominently in the lives of those who went on to pursue science and technology. “I really admire Bill Nye due to his ability to inject a lot of entertainment and fun into teaching,” says Caltech graduate student Sho Takatori. He was one of those kids who grew up watching Bill Nye the Science Guy, the long-running and award-winning science education series that originally aired on PBS Kids. “His wacky blend of engaging science concepts, wild experimentation, and humor was very compelling. His enthusiasm really got me fired up about science."

Growing up in Sacramento, California, in the 1990s, Takatori was a loyal fan of the show’s fast-paced blend of science and amusement. This appreciation would later inspire him in ways he could have never guessed. After realizing the depth of his zeal for science in high school, Takatori moved on to UC Berkeley to earn a bachelor’s degree in chemical engineering. While there, he worked with the California Environmental Protection Agency to help draft regulatory policies for the California Green Chemistry Initiative, a regulatory effort to develop safer chemicals and consumer products through the principles of green chemistry.

Takatori now works in the lab of John F. Brady, Chevron Professor of Chemical Engineering and Mechanical Engineering, where his work focuses on the fluid mechanics of particles suspended in liquids. “I’m looking at self-propelled microscopic particles suspended in a solution, in an area referred to as active soft matter,” he says. “I’m interested in how these tiny bodies move, and in analyzing their mechanics and dynamics.”

Microorganisms often move collectively, much like swarming bees, schools of fish, or flocks of birds. Takatori is studying what he and Brady call “swim pressure,” a unique pressure (or stress) required to confine or contain active bodies inside a region. This kind of research may help explain the pattern formation in all active matter, which can include both living and nonliving entities, including bacteria, certain polymers, and potentially even nanorobots. The primary requirement to be classified as active matter is simply that the particles or organisms be capable of independent motion.

In some cases constituents of active matter, such as bacteria, are propelled by their own bodies. “A perfect example is E. coli bacteria,” Takatori says. “They are only a few microns in size, yet are still able to move using a whiplike appendage, or flagellum.” But in other instances, such as inanimate particles that can be used for focused  drug delivery in the body, there are effects that randomize motion and are independent of larger external forces such as gravity, magnetism, and thermal gradients.

While nonliving particles have different mechanisms behind their movement than living ones, the outcomes are not necessarily that different. “Movement can be biological in nature or due to inanimate interactions, but in both cases the actions can be collective. A passive inanimate object placed into a swarm will move with that swarm,” he says.

Although Takatori is involved in fundamental research, there are a lot of practical applications for this kind of work, he says. By studying how active bodies such as bacteria and molecular proteins move in fluid environments, researchers can better understand how to control the motion of active systems.

“This type of information could lead to the development of new delivery systems for pharmaceuticals and to novel materials,” he says.

For example, Takatori is currently working in the laboratory to fabricate soft, compressible materials that can have their size, shape, and motion manipulated by loading the material  with active matter. He hopes to create materials that can compress or expand, elongate, and move on command, and that could one day be used to create micro- or nanomechanical devices and motors that could have multiple applications in medicine and other fields.

If watching Bill Nye as a kid sparked Takatori’s interest in science, his enthusiasm for teaching was positively ignited by the performer and engineer. “To keep people engaged, especially students, you need to make science fun, and I really admire Bill Nye’s ability to do that,” he says.

It appears that students admire Takatori’s ability to do it as well. In spring 2015, his own teaching style in a fluid dynamics class resulted in the Excellence in Teaching as a Teaching Assistant award from Caltech’s Graduate Student Council.

Reactions from his students range from enthusiastic to downright effusive. “Sho is perhaps the best TA I’ve ever had. He explained everything with crystalline clarity and was always available and happy to help,” said one. And Takatori’s personal favorite? “You may have to fire Sho because he makes every other instructor look bad. I do not think it would be possible for him to improve his performance without coming to our rooms at night and whispering course material in our ears as we fell asleep.”

“When I read that one, I thought it was hilarious,” Takatori says. “When you get a comment like that, from even one student, it makes it all worthwhile.”

Making science fun may look easy to his students, but it takes a lot of preparation, Takatori says. “A few hours before a class, I will copy all of my lecture notes by hand. Since the equations are fresh in my head, I can write them on the chalkboard without referring to notes. This way, I think I appear more confident and seem like I know what’s going on from the students’ perspective.”

Like any grad student, Takatori has faced challenges. But one goes well beyond the norm and continues to apply pressure to his performance as a student, teacher, and researcher.

“In my sophomore year of high school, I was diagnosed with ulcerative colitis, a chronic autoimmune disease,” he remembers. “I continue to have flare-ups every year or two, and they might last a couple of months. When it gets bad, I can’t even leave home, and I might lose 10 or 12 pounds.”

Takatori’s medical condition has resulted in a lot of time spent in clinics and hospital rooms, experiences he says have contributed to his desire to help others through teaching and mentoring. But this drive also extends to the lab, where he hopes his work might enable better delivery of medicines. “I’ve always enjoyed teaching and public speaking, but there’s something about the act of doing, of creating something that will help people, that’s just incredibly rewarding,” he says.

—Rod Pyle

Header Photo by Mario de Lopez Photography