Why We Love Objects With Moving Parts

We may envision the future as sleek and smooth, but we shouldn’t forget the value of cogs, switches, and buttons.

When we think of futuristic user interfaces, we often envision expansive, glossy, multi-touch surfaces. Whether we realize it or not, one of the most influential architects of these preconceptions is the television series Star Trek: The Next Generation. While designing what became known as LCARS, or Library Computer Access/Retrieval System, scenic art supervisor and technical consultant Michael Okuda was asked to come up with visuals that appeared more advanced than what the original Star Trek franchise depicted, but on a relatively paltry television budget. Rather than constructing intricate physical consoles, Okuda chose to use inexpensive backlit sheets of Plexiglas which, over time, became increasingly animated in order to reinforce the illusion of interactivity.


Our perceptions around both modern and futuristic device interactions are dramatically influenced by television and movies, but television and movies aren’t necessarily influenced by practical or carefully researched user experiences. Rather, networks and studios are far more concerned with things like budget, the need to quickly and effectively communicate futuristic settings to the audience, and the desire to present novel, engaging, and CGI-compatible visuals. In other words, fictional technology doesn’t actually have to be effective; it just has to avoid the appearance of being completely ineffective.

Morn/Wiki Commons

As we’ve seen from shows like The Next Generation, one of the easiest ways to place technology in the future—and, at the same time, create inexpensive effects—is to eschew as many moving parts as possible. But we need to be careful not to confuse actors carrying around slabs of Lucite that can be brought to life in post-production with the kinds of devices, interactions, and futures we actually want for ourselves.

Boston Public Library Flickr

The Allure of Cause and Effect
Anyone who has spent any time at all around toddlers knows that most have an inherent fascination with buttons, switches, and knobs, and specifically with the cause-and-effect relationships they usually encapsulate. As we grow older, we find ourselves captivated by grown-up versions of these toys: things like pneumatic tubes (probably the closest thing there is to a physical manifestation of the Internet), Rube Goldberg machines, and the insides of automatic watches glimpsed through transparent, synthetic sapphire case-backs.


There are even mechanisms known to industrial designers as “placebo buttons” sprinkled surreptitiously throughout our environments, non-functioning push-buttons in places like elevators, trains, and crosswalks designed to placate us by giving us the illusion of control in situations that have long since been entirely automated. If we pay close attention to these types of clues, and how they signify the ways in which we are not only compelled to interact with our environments, but indeed anatomically optimized to manipulate our surroundings, we can see that, despite what science fiction prophecies, there is still a great deal of value and satisfaction to be found in physical, tactile experiences.


Pushing Buttons
Technological progress has long been associated with the miniaturization, reduction, and the elimination of moving parts. Consider the evolution of devices like grandfather clocks and mechanical watches to quartz modules, and now to the microprocessors and touchscreens of smart watches; rotary phones, to touch-tone dial pads, to the capacitive multi-touch displays on our smartphones; mechanical typewriters, to computer keyboards, to virtual keyboards; the electromechanical split-flap displays of old alarm clocks and departure boards in train stations and airports, to LEDs, LCDs, and electronic paper. The list goes on and on.

One of the most interesting examples of where moving parts have managed to persist in the face of modern technology is the iPhone. I was initially surprised to see iPhones retain their physical “home” buttons throughout their evolution, since not only does it increases the overall length of the phone by at least a centimeter, but the mechanism also went through a period of being notoriously unreliable. Why, then, would a company seemingly so obsessed with simplification and clean design—one of the first companies to replace mechanical drives with flash storage, cords with Bluetooth, scroll wheels with multi-touch, physical latches with magnets, optical drives with gigabit Ethernet, and most recently, trackpads with an integrated button with static Force Touch trackpads—not only continue to tolerate all the disadvantages and complexities of such a critical and frequently used moving part, but even build additional functionality into it, such as a fingerprint sensor?


The easy answer is that physical mechanisms can be operated without looking (picture increasing the volume of a favorite track without having to interrupt your workout, or reaching down and dismissing an incoming call without having to break eye contact with a client). But there’s another less tangible yet more interesting explanation: the iPhone’s physical home button makes users feel secure, and that security is more important than simplifying the design and manufacturing process. No matter how lost you might find yourself in the hierarchical convolutions of an application’s menus, pressing the home button always takes you back to a safe and familiar location. Of course, a “soft” (or virtual) button such as those we’ve become accustomed to on many Android devices would serve the same purpose, so why go to all the trouble to make it not only physically depress, but also produce a very specific type of crisp, tactile actuation?

Because “clicking” requires physical force, and since that physical force provides tactile feedback, it’s much better for both communicating intent, and for preventing accidental activations. Additionally, mechanical moving parts somehow feel “lower level” and more robust than their virtualized counterparts—less likely to “freeze” or ignore user input when the device they’re connected to is acting glitchy. It takes us back to that same cause-and-effect relationship most of us practiced over and over again as infants with activity boards, and with every other tactile mechanism we could get our little fingers on.

Nataliya Hora via Shutterstock

The Future of Moving Parts
One of the mistakes in assuming that the evolution of technology will always lead to the elimination of moving parts is the assumption that moving parts themselves are somehow immune to that same evolutionary process. That’s almost certainly not the case. Rather than thinking of moving parts as largely obsolete mechanisms to be avoided at all costs, there’s an opportunity for us to fundamentally reimagine the nature of how components and materials interact with one another.


Nanomechanics might one day be used to assemble macroscopic systems that not only move and adapt in entirely novel ways, but are also capable of repairing themselves in real time. Advances in materials science and quantum chemistry could lead to mechanisms that are several orders of magnitude more resistant to wear than what we currently have, dramatically reducing—or even entirely eliminating—the maintenance requirements and unpredictability that we often associate with some of today’s moving parts. And finally, technologies like magnetic levitation could lead to the ability to transfer power between mechanical components, or switch on and off an electric circuit, without any physical contact whatsoever (imagine entirely frictionless magnetic gears suspended in permanent alignment, and buttons that float in their sockets on magnetic cushions). The future could be assembled out of entirely mechanical components with almost no material fatigue to limit their lifespans.

One way to solve the problems associated with moving parts is, of course, to simply eliminate those moving parts altogether. And in industrial contexts, where designing and engineering solutions that require fewer moving parts can save space, reduce costs, and increase durability, technologies like bladeless wind turbines can make a lot of sense. But when it comes to more personal technology—devices that we frequently touch, hold, or wear—figuring out how to mitigate the challenges of moving parts is a much more interesting approach, one that recognizes the value of the tactile experience.


About the author

Christian Cantrell is a science fiction author, freelance tech writer, and Engineering Manager on Adobe's Experience Design Team.