There’s one wearable technology that, for sheer amount of time on screen and number of uses, eclipses all others, so let’s start with that. Star Trek: The Next Generation introduced a technology called a combadge. This communication device is a badge designed with the Starfleet insignia, roughly 10cm wide and tall, that affixes to the left breast of Starfleet uniforms. It grants its wearer a voice communication channel to other personnel as well as the ship’s computer. (And as Memory Alpha details, the device can also do so much more.)

Chapter 10 of Make It So: Interaction Design Lessons from Science Fiction covers the combadge as a communication device. But in this writeup we’ll consider it as a wearable technology.

How do you use it?

To activate it, the crewman reaches up with his right hand and taps the badge once. A small noise confirms that the channel has been opened and the crewman is free to speak. A small but powerful speaker provides output that can be heard against reasonable background noise, and even to announce an incoming call. To close the channel, the crewman reaches back up to the combadge and double-taps its surface. Alternately, the other party can just “hang up.”

This one device illustrates of the primary issues germane to wearable technology. It’s perfectly wearable, social, easy to access, prevents accidental activation, and utilizes apposite inputs and outputs.

Wearable

Sartorial

The combadge is light, thin, appropriately sized, and durable. It stays in place but is casually removable. There might be some question about its hard, pointy edges, but given its standard location on the left breast, this never presents a poking hazard.

Social

Wearable tech exists in our social space, and so has to fit into our social selves. The combadge is styled appropriately to work on a military uniform. It is sleek, sober, and dynamic. It could work as is, even without the functional aspects. That it is distributed to personnel and part of the uniform means it doesn’t suffer the vagaries of fashion, but it helps that it looks pretty cool.

As noted in the book, since it is a wireless microphone, it really should have some noticeable visual signal for others to know when it’s on, so they know that there might be an eavesdropper or when they might be recorded. Other than breaking this rule of politeness, the combadge suits Starfleet’s social requirements quite well.

I don’t recall ever seeing scenes where multiple personnel try to use their combadges near each other at the same time and having trouble as a result. I don’t recall this from the show (and Memory-Alpha doesn’t mention it) but I presume the combadges are keyed to the voice of the user to help solve this sort of problem, so it can be used socially.

Technology

Easy to access and use

Being worn on the left breast of the uniform means that it’s in an ideal position to activate with a touch from the right hand (and only a little more difficult for lefties). The wearer almost doesn’t need to even move his shoulder. This low-resistance activation makes sense since it is likely to be accessed often, and often in urgent situations.

Tough to accidentally activate

In this location it’s also difficult to accidentally activate. It’s rare that other people’s hands are near there, and when they are, its close enough to the wearers face that they know it and can avoid it if they need to.

Apposite I/O

The surface of the body is a pretty crappy place to try and implement WIMP models of interface design. Using touch for activation/deactivation and voice for commands fit most common uses of the device. It’s easy to imagine scenarios where silence might be crucial. In these cases it would be awesome if the combadge could read the musculature of its wearer to register subvocalized commands and communication.

The fact that the combadge announces an incoming call with audio could prove problematic if the wearer is in a very noisy environment, is in the middle of a conversation, or in a situation where silence is critical. Rather than use an “ring” with an audio announcement, a better approach might build in intensity: a haptic vibration for the initial or first several “rings,” and adding the announcement only later. This gives the wearer an opportunity to notice it amidst noise, silence it if noise would be unwelcome, and still provide an audible signal that told others engaged with the wearer what’s happening and that he may need to excuse himself.

So, as far as wearable tech goes, not only is it the most familiar, but it’s pretty good, and pretty illustrative of the categories of analysis applicable to all wearable interfaces. Next we’ll take a look at other wearable communications technologies in the survey, using them to illustrate these concepts, and see what new things they add.