Hitting the Books: What Wearables of Tomorrow Could Look Like

Apple's Watch Ultra, with its 2,000-nit digital display and GPS capabilities, is a far cry from its Revolutionary War-era self-winding ancestors. What kinds of wonderful body-mounted technologies might we see in a hundred years? In his new book, The Skeptic's Guide to the Future, Dr. Steven Novella (with help from his brothers, Bob and Jay Novella) examines the history of devices wearables and technologies that allow them to extrapolate where new advances in flexible circuits, wireless connectivity and thermoelectric power generation might lead.

Grand Central Publishing

Excerpt from The Skeptics' Guide to the Future: What Yesterday's Science and Science Fiction Tell Us About the World of Tomorrow by Dr. Steven Novella, with Bob Novella and Jay Novelle. Copyright © 2022 by SGU Productions, Inc. Reprinted with permission from Grand Central Publishing. All rights reserved.

As the name suggests, wearable technology is simply technology designed to be worn, so it will evolve as technology advances. For example, as timekeeping technology advanced, so did the wristwatch, leading to today's smartwatches. Some advances lend themselves particularly well to wearable technology. One of these developments is miniaturization.

The ability to make technology smaller is a general trend that benefits wearable devices by increasing the number of technologies that are small enough to be worn conveniently and comfortably. We are all now familiar with the incredible miniaturization of the electronics industry, and in particular computer chip technology. Postage stamp-sized chips are now more powerful than computers that would have filled entire rooms in previous decades.

As evidenced by the high-quality cameras on a typical smartphone, optical technology has already become significantly miniaturized. Research is underway into even smaller optics, using metamaterials to produce telephoto and zoom lenses without the need for bulky glass.

"Nanotechnology" is now a collective buzzword for machines built on a microscopic scale (although technically it's still much smaller), and of course nanotechnology will have incredible implications for wearable devices .

We are also at the dawn of flexible electronics, also called "flex circuits" and more collectively "flex tech". It involves printing circuits on a flexible plastic substrate, allowing for smoother technology that moves as we move. Flexible technology can be more easily incorporated into garments, even woven into their fabric. The advent of two-dimensional materials, such as carbon nanotubes, which can form the basis of electronics and circuits, are also very flexible. Organic circuitry is another technology that allows circuitry to be made in a flexible material, rather than just printed on a flexible material.

Circuits can also be printed directly on the skin, like a tattoo, using conductive inks that can act as sensors. One company, Tech Tats, already offers such a tattoo for medical follow-up purposes. The ink is printed into the upper layers of the skin, so they are not permanent. They can monitor things like heart rate and communicate that information wirelessly to a smartphone.

Portable electronic devices must be powered. Small watch batteries already exist, but they have finite energy. Fortunately, there are a host of technologies in development that can harvest small amounts of energy from the environment to power wearable devices (in addition to implantable devices and other small electronics). Perhaps the earliest example of this is the self-winding watch, the earliest evidence of which dates back to 1776. Swiss watchmaker Abraham-Louis Perrelet developed a pocket watch with a pendulum that would wind the watch from the walking movement normal. It would have taken a 15 minute walk to...