Cartier is rare among watch manufacturers because it releases concept watches that reveal its future plans for all to see. The latest concept, called ID Two, looks like something teleported to us from the year 2020. Click here to read WatchTime technical editor Mike Disher’s report on the ID Two, along with a video animation of how it works.
With Ph.D. presenters and demonstrations worthy of a physics class, the ID Two press event in Neuchâtel was more like a science fair than a watch launch. To illustrate some of the ID Two’s features, Cartier’s think-tank team boiled water at room temperature, created a vacuum in a watch case, and made a piece of paper drop like a stone. In a series of four workshops, the team showed off the ID Two’s features, including a crystal-clear case, mainsprings fashioned from optical fibers, and a movement that exists in a vacuum. This is the future according to Cartier. (Click below the photos for Cartier’s video animation that introduces the concept watch.)
The Case of the Missing Air
The ID Two’s most visually striking feature is its clear case, which is made from a material that is new to watchmaking. Cartier calls the material Ceramyst. It’s a polycrystalline ceramic consisting of magnesium, aluminum and oxygen. Unlike synthetic sapphire, Ceramyst can be molded – it does not require laborious machining and polishing. If you’re wondering whether the clear case is tough, Cartier says it’s the same material used for the bulletproof windows at the White House.
The case is manufactured in two parts: The main case, including the lugs and crystal, are formed as a single unit. The second part is the caseback. Because the material can be molded, it can be formed into complex shapes.
The case material is extremely dense, and the two-part construction reduces the gasket length by 48 percent compared with a traditional design. These features facilitate another intriguing ID Two feature: a 99.8-percent vacuum inside the case.
Why a vacuum? Because the air inside a watch case has a greater effect on the movement than you might think. It is common knowledge that air pushes against, or resists, things trying to move through it. To demonstrate this general principle, Cartier placed a small piece of paper, about the size of a quarter, at one end of a long glass tube about 3 inches in diameter. When the tube was turned to the vertical position, the piece of paper drifted slowly to the bottom, taking several seconds to make the trip. Then the demonstration was repeated, this time after the air in the tube was removed with a pump. With the air gone, the piece of paper dropped like a stone.
To illustrate how the air inside a watch case affects the balance wheel, specifically, Cartier performed another of its science-class demonstrations. The results were surprising. A Calibre de Cartier watch with 1904 caliber – minus the bracelet – was mounted on a stand, dial down. The balance wheel was tuned to oscillate at a lower-than-average amplitude of 140 degrees (we will see why in a minute). A plastic hose ran from the watch case to an air pump.
The watch was also connected to a Witschi timing machine and to an air pressure gauge, and the Witschi timer and pressure gauge readings were displayed on a computer monitor, along with a video image of the balance wheel. Together, the various devices could pump the air out of the watch while displaying the air pressure inside the case and the effect on the balance wheel’s performance.
The air pump was turned on and the air pressure inside the watch began to fall. As it did, the balance wheel’s amplitude increased. When the pump had removed as much air as it could, the amplitude had increased by a full 67 degrees. When the pump was turned off, the air pressure inside the watch slowly returned to normal, and as it did, the balance’s amplitude dropped, eventually returning to 140 degrees. (The amplitude had to begin at a below-average value to leave room for the significant increase.)
Given the balance wheel’s small size and aerodynamic shape, the fact that removing the air from the case generated a nearly 50-percent improvement in amplitude came as a big surprise. It’s like finding out that in a vacuum, a Honda Civic can do over 200 mph.
In addition to improving the escapement’s performance, the vacuum inside the case has an aesthetic benefit: It holds the caseback firmly in place without the use of screws or threads.
Maintaining the vacuum inside the watch case presented another technical challenge. Traditional rubber gaskets designed to protect against water are largely ineffective against air, because tiny air molecules pass right through standard gaskets. Cartier needed a new gasket material. Its solution, dubbed “nanoparticle” gaskets, involves infusing rubber with tiny particles to increase the rubber’s density, and so its ability to block air molecules. The particles added to the rubber are made from a decidedly low-tech material: clay. Cartier says that the Ceramyst case and nanoparticle gaskets will maintain the near-total vacuum inside the case for “several years.”