How the World Works: A Compelling Case for Becoming an Engineer

How the World Flows

(Oxford University Press, by Albert Folch, now available)

What do rainbows, inkjet printers, human skin, pregnancy tests, and fish gills have in common?

To explore this, you must delve into what Albert Folch, a bioengineering professor at the University of Washington, terms the “liliptian fluid world.” Here, we encounter the fascinating realm of microfluidics, which manages liquids at a miniature scale—from tiny veins in the human body to microchannels etched into lab chips.

Folch’s new book, How the World Flows: Microfluids from Raindrops to COVID Tests, is an astonishing journey through the numerous ways microfluidics influence our world. He credits his neurobiologist wife in the acknowledgments for encouraging him to write about not just microfluidic chips, which have become crucial in chemistry, biology, and medical research, but also about the “device” of microfluidics found in nature.

This allows the book to paint broader pictures, examining both current technologies and historical examples, from handheld DNA sequencing devices to how the tallest trees draw nutrients from the soil. Folch also explains phenomena like capillarity in paper—enabling writing—and discusses the fundamental mechanics of a candle and the workings of an automobile engine.

Each of the 18 chapters is brief and introductory, starting with a personal story about a historical figure, such as inventors, athletes, and chefs, making the material more relatable.

Physics concepts in How the World Flows, like viscosity, surface tension, and gravity, are presented without complex equations but instead through straightforward explanations rooted in real-world contexts.

At times, I’ve yearned for deeper detail regarding the devices and processes Folch discusses. Additionally, the coverage of recent innovations, including chip-sized devices that replicate entire organs, feels somewhat limited compared to the wealth of historical context.

Nevertheless, as I read, I felt I was absorbing a wealth of knowledge about everyday phenomena. Microfluids have become essential in understanding our bipedalism due to sweat, why lakes don’t drain into the Earth, and how all vertebrates can perceive each other’s calls. There’s even a section on the complex engineering found in a mosquito’s proboscis!

Folch’s writing exudes enthusiasm and warmth, though he occasionally slips into the realm of popular science writing that can obscure the overall tone of the book. For instance, many scientific contributions are intertwined with childhood anecdotes, which can shift from relatable to hagiography.

I also found it remarkable that a book could make microfluidics accessible to those without rigorous educational backgrounds.

Despite this, the strength of How the World Flows lies in its diverse cast of characters and its emphasis on the significance of microfluidics in shaping our world.

Above all, this book has the potential to inspire young readers to consider a future in engineering. It also serves as a reminder of the intricate complexity and wonder of any object under a microscope, fueling our curiosity.