If it seems that modern wristwear is more Silicon Valley than Vallée de Joux, then take a closer look at the latest movement innovations coming out of Switzerland. You may be surprised to find that tiny slices of silicon are making their way into watches from the most traditional of manufacturers.
Although at the cutting edge of watch technology, silicon has a long, if patchy, history with watchmaking. Its first appearance was not as pure silicon but as the main constituent of glass; yes, that material we all assume to be fragile and brittle was explored to be both shock-resistant and flexible.
Robert Hook, along with Christiaan Huygens – the inventor of the balance spring – made a patent application for a glass version of the piece as far back as 1660. Glass was revisited for use in both springs and balances by those giants of English watchmaking Dent and Arnold which submitted timepieces for testing at Greenwich Observatory in the mid-19th century. Sadly, accuracy could not be improved to an acceptable level and the use of glass was subsequently abandoned.
In 2001, Ulysse Nardin shocked the watch world with the launch of ‘The Freak’. Its innovative construction, with the rotation of the movement itself showing the passage of time, was actually only half of the whole story. This watch was the first use of silicon in a modern watch; silicon in its pure form rather than mixed into glass.
Silicon has many of the attractive properties of glass, low density, hardness, flexibility and imperviousness to magnetism, but is much more manageable. Technology developed by the electronics industry such as ‘Deep Reactive Ion Etching’ (DRIE) allows tiny components to be cut in vast numbers with absolute precision.
The early 2000s saw an unlikely partnership between Patek Philippe, Swatch Group and Rolex to develop silicon watch components. Partnering with CSEM, the Swiss Center for Electronics and Microtechnology, each company developed its own components and used them in its own way.
Patek Philippe began with the escape wheel creating a silicon oxide it dubbed ‘Silinvar’, this was followed in 2006 by the brand’s flat hairspring with a patented terminal curve – ‘Spiromax’ and in 2008 the escapement was complete with both the pallet lever and escape wheel made from Silinvar – ‘Pulsomax’.
Breguet was the pioneer brand for the Swatch Group, and pursued different strategies for different models. The 5177 was initially equipped with only the pallets and escape wheel in silicon, while the 5197 received a silicon flat balance spring in addition.
Breguet wouldn’t be Breguet without a Breguet overcoil spring, but producing 3D shapes in silicon is hard, a challenge met by the brand using a minute joint to attach the horizontal and vertical sections together. Breguet has since produced a double silicon hairspring and introduced the original version into a wider range of models.
Watchmakers have used properties of silicon to develop radical movement concepts
Swatch Group has taken this technology and introduced it to more and more brands, initially Omega, then Longines and this year Hamilton received the first silicon-equipped 7750 chronograph movement.
Rolex, in typical fashion, took its time in introducing this innovation into its product line. It wasn’t until 2014 that the first component, a ‘Syloxi’ hairspring, made its appearance. Not only did it take an extra eight years, but it surreptitiously released this development into calibre 2236, a new movement for women’s watches.
Silicon had been used to create recognisable watch parts, albeit with slight tweaks. More recently, watchmakers have used properties of silicon to develop movement concepts as radical as the ‘Freak’. In 2013, Girard-Perregaux used a silicon blade six times thinner than a human hair as the key element in its ‘Constant Force Escapement’, while in 2017 Zenith used a single, intricate piece of silicon to replace 30 individual components.
The Zenith calibre ZO342, used in the Defy Lab, takes all the properties of silicon and harnesses them to produce a movement that runs at 15 hertz (more than three times as fast as a regular watch), this improves the rate stability and, in turn, timekeeping. The tiny vibrations of the silicon oscillator make the system highly efficient giving a power reserve of five days.
Many critics of this ‘wonder material’ have raised questions as to how future-proof these new movements will be. Certainly, it will be very difficult for traditionally trained watchmakers to work on these watches, and access to the silicon parts will be highly restricted, but as for parts availability: I am reminded of my visit to Nivarox-FAR in 2008 to see the production of silicon springs.
The conventional hairsprings were made by a rolling mill so sensitive that our presence in the room pushed it out of tolerance and that 20 minutes’ worth of production had to be scrapped.
The silicon springs by contrast, etched out in vast numbers, littered the presentation desk and the floor around it like wedding confetti. Future supply will never be a problem when they can produce and stockpile so many components so easily.