Though e-ink watches have been around for a few years now, most, like the Touch Time, tend to follow the same form factor as their LCD-screened cousins, which are themselves based on analog ancestors. The patent-pending CST-01 from Chicago-based Central Standard Timing is a different proposition altogether. Claimed to be the world's thinnest watch at just 0.8 mm thin, yet still managing to squeeze in a rechargeable battery, it makes use of segmented (rather than pixel-based) e-ink technology, has no buttons or knobs and has only one function ... to let its wearer know what time it is.

The brainchild of Dave Vondle (interaction designer and electrical engineer) and Jerry O'Leary (industrial designer and mechanical engineer), the CST-01 makes use of e-ink SURF segmented display technology from E Ink. Of the 64 available segments, the CST-01 watch uses up 63 to show the numbers. The stylish time piece comes with a white-on-black/black-on-white display (with a custom font) that's readable in sunlight with a 180-degree viewing angle.

The lack of a back-light does mean that you won't be able to see the display in total darkness, but a little ambient light should make the face visible.

"After wearing this for a while I can say that reading at night has not been an issue," Vondle told us. "The numbers are so large and the contrast so high that you would need to be in pitch dark to have trouble reading it. Reading it in places like outside at night in a city or dim bars/nightclubs is not an issue."

A single piece of flexible stainless steel has a 0.5 mm channel etched into its upper surface, into which the flexible e-ink components, the Seiko Epson SoC (system on a chip) processing powerhouse that drives the display, and an embedded Thinergy Micro-Energy Cell are laminated. The onboard battery charges in 10 minutes from an external dock, has a lifetime of 15 years (or 10,000 recharge cycles) and is expected to last a month between charges. The 12 g (0.4 oz) CST-01 is held in place on the charger using magnets.

"It uses pogo-pins on the charger and gold-plated contacts on the watch," explained Vondle. "This is somewhat similar to the way a magsafe connector attaches to Apple laptops. We are investigating inductive charging to further increase waterproofing. The charger is powered from micro-USB and all setting of time happens with the knob on the charger. We are investigating setting the time automatically with a helper app on a Mac/PC but this is still early in development."

"The Thinergy Micro-Energy Cell simply stops pulling current when the battery is charged," he added. "The charger can sense this and the LED lights up green when it's done. "

The project launched on Kickstarter on January 8 and was funded less than two days later. The campaign is set to run until February 22, and pledges of at least US$129 will now be needed to secure a production version of the CST-01 in either black or white (or $229 for one of each) plus a charging base station.

With funding secured, the designers are currently working on product revisions that will give the CST-01 as much waterproofing as possible, optimize its scratch resistance and are also looking into the development of a travel charger. At the close of the Kickstarter campaign, Central Standard Timing will continue to take pre-orders for the CST-01 on its website.

While the orientation of the display may take some getting used to, there's no denying that the CST-01 is one distinctive time piece.

"Early on in the development process we experimented with all sorts of different layouts and one of those was a vertical orientation," Vondle recently told backers. "We chose our design for a variety of reasons, one being that it is a more simple and classic layout for displaying the time. After wearing the watch for a few days, we found that we start to check the time differently and it is in many ways preferable. The numbers are so large and high contrast, we don't need to lift the watch close to our faces to read it, we can simply glance down at our wrists and read the time."

The Kickstarter campaign video from Central Standard Timing appears below.

Source: Central Standard Timing, Kickstarter page