Open the caseback of a modern luxury watch from one of Switzerland’s top maisons, and you may be looking at something that would have been unthinkable to a watchmaker fifty years ago.
Where once you’d find a hairspring drawn from a strand of Nivarox alloy – shaped, tempered, and adjusted by hand – you might now find a component grown on a silicon wafer in a clean room, etched to micron-level precision by a process borrowed from the semiconductor industry.
What Is Silicium?
Silicium is the French term for silicon – the semi-metallic element used widely in electronics manufacturing. In watchmaking, it refers to monocrystalline silicon components machined using Deep Reactive Ion Etching (DRIE), the same process used to produce semiconductor chips.
The material’s properties make it almost tailor-made for a mechanical movement:
- Non-magnetic – Entirely immune to magnetic fields, one of the greatest enemies of precision timekeeping in an age of smartphones and induction chargers.
- Thermally stable – Its extremely low coefficient of thermal expansion means it barely changes dimensions with temperature shifts.
- Self-lubricating – Components require little to no lubrication, one of the primary reasons movements degrade over time.
- Geometrically precise – Because silicon hairsprings are grown and etched rather than drawn and shaped, they can be produced to a level of consistency that hand-finishing cannot match at scale.
On paper, the result is a movement that is more accurate, more resistant to the modern environment, and less demanding to service.
How Silicon Entered the Industry
Silicon’s entry into commercial watchmaking began in 2001, when Ulysse Nardin unveiled the Freak – the first production watch to house silicon escapement components. At the time it was a curiosity. Within a few years it had become a starting pistol.
In 2006, Patek Philippe introduced its Spiromax hairspring in Silinvar – a silicon-based material developed through a joint research programme with Rolex and the Swatch Group, via the Centre Suisse d’Electronique et de Microtechnique (CSEM). The resulting patents gave these three groups early exclusive access to the technology, which is why silicon components spread first through Patek Philippe, Omega, Breguet, and Rolex before reaching the wider industry.
Omega introduced its Si14 silicon hairspring in 2008, laying the groundwork for the Co-Axial Master Chronometer movements that now define its upper range. Rolex took a more measured approach, developing its proprietary Syloxi hairspring for selected calibres from 2014 – most recently deployed in the Calibre 7135 powering the 2025 Land-Dweller.
As key patents have expired, the technology has spread further. Today, silicon components appear in everything from Tissot’s Powermatic 80 to Tudor’s Black Bay range – a democratisation that would have seemed unlikely when the Freak first appeared two decades ago.
What Traditional Materials Still Do Best
The case for silicium is strong on paper, but traditional materials retain important advantages – and passionate advocates.
The Repairability Argument
Watchmakers trained in classical techniques point out that a steel or Nivarox hairspring can be adjusted and repaired by a skilled human hand. A broken silicon spring cannot be reformed – it must be replaced entirely. The late George Daniels, widely considered the greatest independent watchmaker of the 20th century, was openly sceptical of silicon, arguing that the value of mechanical watchmaking lies in hand craftsmanship, not computer-controlled etching.
Fragility Under Stress
Silicon is brittle rather than ductile. Where a steel hairspring might bend under a severe shock, a silicon one can shatter. For watches worn hard and often, this is a practical distinction worth understanding before you buy.
The Craft Question
A hand-finished Nivarox hairspring, adjusted across five or six positions by a skilled watchmaker, represents something silicon cannot replicate: human craft applied at the level of the invisible. Jaeger-LeCoultre, which has maintained a largely traditional approach to movement materials, continues to offer some of the longest warranty periods in the industry – suggesting longevity is not exclusive to silicon.
Does Movement Technology Affect Resale Value?
For most modern luxury watches, the presence of silicon components is broadly neutral in terms of resale value – and in some cases, actively positive.
A Rolex with Syloxi or Parachrom technology, an Omega with a Co-Axial Master Chronometer movement, or a Patek with the full Oscillomax suite are all perceived as improvements over their predecessors. Technically informed buyers treat these as desirable features, and they tend to support a watch’s secondary market position rather than undermine it.
Where the picture changes is at the very top of the collector market. A complicated dress watch admired through a display caseback for the beauty of its movement may carry more appeal with classically finished components than with a silicon-laden calibre. At this level, craftsmanship and finishing can matter as much as mechanical performance.
For the vast majority of modern luxury timepieces, though, silicon is no longer a novelty – it is an expectation. Watches that lack the anti-magnetic, low-maintenance properties it provides may gradually look like less compelling propositions against updated references from the same brands.
Where Things Are Heading
The broader direction of travel is clear. With key foundational patents now expired, silicon technology is accessible to more manufacturers than at any point since the Freak. New applications are emerging beyond the hairspring – silicon escapement levers, monobloc oscillators, and constant-force flexure systems have all been demonstrated by leading brands.
That said, the industry has not abandoned traditional materials. Many brands are pursuing hybrid approaches: silicon hairsprings in movements that retain classical finishing, hand-bevelled bridges, and blued steel screws. The goal is the best of both worlds – the performance of silicium alongside the visual and philosophical identity of mechanical craftsmanship.
