When I was a kid, I used to dream of a world where everything was small. I think it all started when I visited Madurodam in the Netherlands one summer. The scaled-down replicas of famous buildings from all around Holland looked so realistic. The nine foot long Boeing 747 in the airport, the tiny boats in the canals bringing cheese to the cheese market. All the details. Perfect and beautiful. But then I noticed that nothing was really working. Some boats, airplanes and cars would move, but they used tracks to pull them along. Not exactly realistic. This got me dreaming about an improved version of Madurodam where everything, every last detail, actually worked. It turns out this is really hard to do. Most of the parts that make things go stop working when you scale them down in size. Why? You guessed it, Physics. When Madurodam scaled everything to be 25 times smaller than actual size, the volume decreased by a factor of 15,625 (25 cubed), but surface area only decreased by a factor of 625 (25 squared). If a car in Madurodam were a true replica of a life sized automobile, the engine inside this car would have fifteen thousand times lower engine power (volume), but only six hundred times smaller friction (surface area). In other words, surface effects would dominate and the car would not work.
As an adult with thinning gray hair, I still fancy a world where everything is small. It’s just that I now realize that the inner workings of devices in such a world are forced to be different from the man-sized technology we use today. This is not a personal revelation. I have learned this from the numerous scholars, engineers, and scientists that have dedicated their lives to miniaturization ever since Feynman’s famous presentation “There is Plenty of Room at the Bottom: an Invitation to Enter a New Field of Physics”. Through their work, I have learned that there are certain aspects of Physics that, unlike surface to volume ratio, scale favorably with size. This means that smaller devices can work if you use completely different mechanisms to build them. Going back to the car engine example, it turns out that there are some forces that get proportionately larger the smaller the device becomes. For example, electrostatic force, the force between electrically charged surfaces, is largely independent of scale. This means an electrostatic engine gets relatively stronger the smaller it becomes. If someone were to make a super small car, it may sport a powerful electrostatic engine under the tiny hood.
Every once in a while I visit an elementary school to give a presentation about miniaturization. After the kids compete to see who can write their name the smallest and I declare them all winners, I ask the kids to draw what they would choose to make tiny, if they could. Pages filled with cars, houses, boats, TVs, airplanes, people, animals, and less pleasant real-life things like guns and missiles soon fill the room, along with excited chatter as they compare their tiny creations. It turns out that making things small is not only my obsession. Kids are truly excited about the prospect of making everything around them small. Miniaturization is engrained in our genes. Literally. Indeed, Mother Nature uses miniaturization for everything she makes. As incomprehensively immense as the Universe is, life is composed of tiny cells, which contain even smaller organelles, themselves formed out of molecules, in turn made out of truly miniature atoms, and on it goes. Miniaturization is in our makeup. It’s what we are. Furthermore, Nature’s example shines a path forward for technological miniaturization, and often teaches us how to go about making something small. Going back to the car engine example, Mother Nature already figured out that electrostatics is a good way to generate force. From the tiny muscles that flap the wings of a mosquito to the muscles in our own bodies, muscle cells create force by taking advantage of the relatively large force between electrical charges at the microscale. That’s what I mean when I say that miniaturization is meant to be.
I think it may be time for me to return to Madurodam. I have not been there since 1978, and I now see miniaturization from a new perspective. This time, I probably will pay close attention to all the ways that Physics stood in the way of making things work inside this diminutive city. Unfortunately, miniaturization is not meant to be easy. But as my teenage daughter’s favorite author Nicholas Sparks said for completely different reasons, “nothing that’s worthwhile is ever easy.”