For those who care only for a watch’s precision, there is no other choice than quartz technology. For other people, mechanical warches are worth some inconveniences. And today the mechanical watch industry is thriving, even though back in the 1970s the Quartz Revolution forced already weakened watchmakers to drive prices down – sometimes even below cost of production – at the expense of quality. Since then the industry has been restructuring and recovering. “The profit margins, nearly nil twenty-five years ago, allow us today to reintroduce techniques, studies, tests and research and development into mechanical watches,” explains Pierre Gygax, technical director of watchmaker Ulysse Nardin.
Accuracy requires extra effort
Even though time measurement is naturally associated with the idea of accuracy, it isn’t in fact that obvious. Whereas an ordinary quartz watch is typically accurate to less than one second per day, a fine mechanical watch can be off between -4 and +6 seconds per day. Yet this very relative precision (that is 1 minute every 10 days) is what the most accurate mechanical movements are able to offer, the very ones that are officially certified. It is indeed the average daily basis accuracy criterion required by COSC (the Official Swiss Chronometer Testing Institute).
The Swiss watch industry giants rely on this certification, with Rolex (600,000 chronometer certificates last year), Omega (200,000) and Breitling (100,000) as leading players. This doesn’t mean that other manufacturers aren’t doing discreetly better, but it certainly does indicate that the majority of Swiss mechanical watches are doing worse since only 1.2 million of the approximately 4 million Swiss mechanical movements manufactured yearly are COSC-certified chronometers.
Weak results considering that precision is one of Switzerland’s hallmarks? Jean-Pierre Musy, technical director of the Swiss manufacturer Patek Philippe, almost agrees: “A tolerance of about -4 to +6 seconds per day should be the mandatory minimum requirement for any so-called superior watch!” As you might guess, Patek Philippe is doing much better since all the watches coming out of its workshops are accurate to -3/+2 seconds per day, and even to -2/+1 in the case of tourbillon wristwatches. Accuracy, waterproofing and reliability are still the main objectives of the watchmakers’ research. The most optimistic observers believe the mechanical watch may one day be accurate to -1/+1 second per day. There is, however, still a long way to go.
Contrary to a common belief, water proofing is more critical for a watch on the ground than at the bottom of the Marianas Trench in the Pacific Ocean. Showers have caused greater damage to watches than deep sea diving, and they are encountered more frequently. Moreover, the sealing of a watch is not only a matter of resistance to water, but also to dust and vapours. The watch wearer’s main enemies are those two environmental factors. Dust blocks the mechanism while aromatic vapours are degrading the oils.
Only half a century ago, most wristwatches were not waterproof. In perfume shops or hair salons, the aromatic vapours in the atmosphere were enough to damage the watch within a fortnight. In La Chaux-de-Fonds, Pierre-Yves Soguel, managing director of Laboratoire Dubois (a company that does accelerated ageing tests for various brands with its Chronofiable process), says the “hairdresser watch syndrome” is no longer relevant. Enormous progress has been made in terms of waterproofing. And not only to divers’ benefit. And then there was silicon…
A mechanical watch uses a power reserve (stored in the mainspring in the barrel) and releases that energy through a train of gears to the escapement, which delivers it to the balance wheel and hairspring that constitute the regulation system. Watchmakers try to store as much power as possible (to provide longer running time and torque) and to optimise its transmission to the regulating system in order to have high frequency (and therefore better accuracy). The bigger the watch, the larger the volumes and the easier it becomes. That, says Soguel, is why the recent “bulky” trend has really facilitated the watchmaker’s job.
Now that the fashion has turned to slightly smaller watches, the exercise is once again becoming more complicated. Watchmakers are looking for the best balance between a longer running period and high frequency. The main alterations or difficulties lie in friction, magnetic fields, temperature changes, humidity and waterproofing, pressure and deformation of the various parts, wear resistance and lubrication, shocks and the weight of components. With this in mind, watchmakers were bound to be particularly interested in strong, light, amorphous materials that are largely insensitive to temperature and magnetic fields. And as it happened, the electronics industry had already developed tested and used such materials.
In the early 2000s, Ludwig Oechslin (who had long worked with Ulysse Nardin and is now curator of the MIH – the International Watch and Clock Museum – in La Chaux-de-Fonds) worked with the Swiss Centre for Electronics and Microtechnology (CSEM) in Neuchâtel on a joint project to develop a silicon spring. Thermal compensation issues seemed insurmountable at the time. But the researchers never gave up, and it was through a project led by Rolex, Swatch Group and Patek Philippe that the first spring made of Silinvar (a patented silicon-based material obtained by a vacuum oxidation process) was developed. In 2006, the first watches made with Silinvar springs became available, and in the meantime research went on to develop other silicon-based parts such as the anchor and the anchor wheel. In 2008, Patek Philippe featured another innovation: the Pulsomax escapement, featuring a much lighter and faster anchor, escape wheel and hairspring in Silinvar with excellent anti-friction properties. Researchers explored other materials, looking for the perfect one. Repeatedly at the forefront of research, Ulysse Nardin made the first balance spring and escapement in artificial diamond in 2002, using the DRIE (deep reactive ion Eetching) process. It did not solve the issue of temperature compensation; but it paved the way for further research and opened up new prospects.Materials and processes of the future
Among all the ongoing studies in the watch industry, there is one field that is mobilizing every laboratory and institute: the LIGA (a German acronym for lithography, electroplating and moulding) process and similar developments. Developed in Germany in the late 1970s, this microfabrication technique combines photolithography and electroforming and has been used in the watch industry for some years now. Industry observers believe it holds great potential.
Quite apart from the specific characteristics of innovative materials, new processes such as LIGA can facilitate further innovation in the form and function of various components, something that wasn’t possible with conventional processing. Alain Vaucher, head of CENTREDOC – the technical information centre for the watchmaking industry – analyses and dissects some 600 patents and articles a month. He believes the LIGA process “actually opens up new prospects for the mechanical watch industry”. In fact, all the watchmakers are investing significant amounts, openly or secretly, in this type of research to ensure they don’t miss this technology switch. Today, the race for patents is especially tough in the fixation of silicon-based components.
In a similar field, Ulysse Nardin presented the latest stage of its research with synthetic diamond-coated silicon components in November 2010 in Sion at Sigatec (a Ulysse Nardin/Mimotec joint venture). This discovery is probably the beginning of a new technological revolution in the watchmaking industry. As Gygax from Ulysse Nardin emphasises: “The elastic properties of diamonds are exceptional and could open up new prospects,” particularly for the production of springs with unique properties.
Elasticity is also a primary concern in other research, as exemplified by Rolex filing the first patent for a barrel spring made of a metallic glass to improve energy storage. Higher frequency To get around the problems related to the hairspring, TAG Heuer came up with a radical solution with its Pendulum: it simply replaced the hairspring and used four magnets instead to regulate the movement. But this is still only a concept.
Another decisive step was also made when Jaeger-LeCoultre and Ulysse Nardin released lubricant-free watches in 2007. Other significant technological breakthroughs being sought– on which many brands focus in secret – are related to raising the frequency of the balance wheel in order to ensure better accuracy and stability. Until recently, the highest frequencies for industrial movements were around 36,000 vibrations per hour (Zenith El Primero). Breguet has just released its latest chronograph using silicon components beating at 72,000 vibrations per hour. Expect more surprises to come.
However, all these new technologies are intended for specific watches, and are necessarily exclusive and expensive. Over time, as has been the case in Formula 1, some technologies will be used in the manufacture of more affordable watches as well. This will trigger other technological leaps forward in mechanical watchmaking.
On the other hand, even greater costs will doom other technologies to remain concepts for a long time, as happens in most high-tech industries. Nevertheless, mechanical watchmaking is at a technological turning point, leading to spectacular increases in precision, reliability, care and maintenance – and probably with extended warranties.
A revolution in watchmaking
Following a presentation by CSEM’s Microsystems Technology Division at a meeting of the ASRH (Association Suisse pour la Recherche Horlogère), a watchmaker realized that the expertise and technology was available that could make his idea for an innovative new escapement device a reality. The idea is simple. A thin strip of silicon, anchored in the middle and at both ends, is compressed. This causes the two halves of the strip to bend – a process known as “buckling”. When a force is applied to one part of the strip, it compresses, then suddenly flips from being buckled in one direction to being buckled in the opposite direction. Thanks to the physical properties of silicon, a tiny, extremely precise quantity of energy is released in the process. Applying the principle to a mechanical watch, the variable energy supplied by the escapement spring is stored in the silicon strip, which changes its state of buckling at a constant rhythm, releasing ultra-precise increments of energy – less than a millijoule at a time – to a mechanical oscillator. The device must be perfectly symmetrical. The strip itself is only 20 microns wide – less than half the thickness of a human hair. The whole thing, including the anchor points and frame, must be made from a single piece of silicon, and small enough to fit into the tiny confines of a watch.
During the past decade, enormous progress has been made in microtechnology and micro-manufacturing equipment and techniques. In collaboration with CSEM, Girard-Perregaux, a brand of the Sowind Group, decided to pursue the watchmaker’s promising idea. A successful prototype of the escapement device, baptized “Constant”, was unveiled at the 2008 Salon International de la Haute Horlogerie.
Currently, Girard-Perregaux, with CSEM’s help, is prototyping a small series of watches fitted with the Constant device. The silicon components for these miniature marvels are made in a dust-free, temperature- and humidity-controlled “clean room” at CSEM. Engineers carry out a complex, deep-reactive etching procedure that carefully peels away layers of atoms from a single block of silicon. CSEM’s technological contribution complements the expertise, experience and technical watchmaking know-how of Girard-Perregaux.
In 2005 Ulysse Nardin introduced the first escapement wheels made in nickel-phosphorous using the lithography, electroplating and molding (LIGA) technology.
Patek Philippe developed a balance spring made of Silinvar, a revolutionary material based on monocrystalline silicon, with a new terminal “curve” design.
A major step in 2007: Ulysse Nardin introduced the first timepiece sporting a synthetic nanocrystal diamond escapement grown on a silicon raw part.
With its Pendulum concept, TAG Heuer replaces the traditional hairspring by magnets to drive the balance wheel.
Breguet Type XXII
Introduced in the spring 2010, the frequency of this watch has been raised to 10 Hertz (i.e. 72,000 vibrations per hour) endowing it with exceptional regulating power.
En français dans le texte
Montres mécaniques high-tech
Les marges retrouvées de l’horlogerie suisse ont ramèné la recherche et développement dans les montres mécaniques. Les horlogers sont d’abord en quête d’un matériau dur, léger, amagnétique, amorphe et peu sensible aux températures. Ce sera le silicium avec dès le début des années 2000 des travaux pionniers via une collaboration d’Ulysse Nardin avec le CSEM. Puis grâce à un projet soutenu par Rolex, Swatch Group et Patek Philippe, les premiers spiraux en Silinvar voient le jour avant de s’étendre à d’autres éléments.
D’autres tentatives pour obtenir les matériaux idéaux sont réalisées en parallèle. Ulysse Nardin réalise en 2002 un spiral en diamant artificiel. Un domaine met particulièrement en ébullition les laboratoires et autres instituts : le procédé LIGA de lithographie/galvanisation/formage. Ulysse Nardin a présenté en novembre 2010 chez Sigatec, à Sion, les derniers développements relatifs aux composants en silicium sur lesquels on fait croître une couche de diamant synthétique nanocristallin (Diamond coated silicon). Outre les caractéristiques des nouveaux matériaux, les procédés mis en œuvre permettent aussi d’obtenir des composants de toute forme. Après le pas décisif qu’a constitué la présentation en 2007 des premières montres sans lubrification par Jaeger-LeCoultre et par Ulysse Nardin, les autres innovations marquantes du moment tiennent à la fréquence du balancier, gage de stabilité et de précision avec un chronographe atteignant les 72’000 alternances par heure présenté par Breguet.
L’horlogerie mécanique est en train de prendre un virage technologique fondamental qui devrait se concrétiser par des avancées spectaculaires en termes de précision, de fiabilité et d’entretien.