"A new material that changed the world of watches." The evolving "silicon magic" seen through Breguet, Girard-Perregaux, Omega, and Louis Moinet

In recent years, "new materials" have become widespread in the watch market. The use of unconventional materials for the exterior and movement of watches has brought about major changes not only in terms of design, such as shape and color, but also in performance. Issue 112 of Chronos Japan featured an article on these "new materials" titled "New Materials That Have Changed Watches," and we've republished it here on webChronos. This time, we're looking at silicon, a material that has provided mechanical watches with high levels of magnetic resistance and shock resistance. Furthermore, this material is evolving itself, opening up new possibilities.

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The current state of Silicon Magic, which has improved the basic strength of its movement

　Silicon, a material that became widespread in the 2000s, has played a key role in significantly changing the nature of mechanical watches. Lightweight, resistant to magnetism, and easily shaped into complex shapes, this material not only provided mechanical watches with high magnetic and shock resistance, but also made new mechanisms possible. Silicon is now on the verge of further evolution.

Silicon material has dramatically changed the nature of mechanical watches

　Silicon was first introduced to the watch industry in 2001 with the Ulysse Nardin Freak. There were several reasons why the company chose silicon, a new and uncharted material. First, they needed a lightweight material to create the new escapement they were using. Initially, they prototyped an escapement out of aluminum, but it was too soft for practical use. So Ulysse Nardin decided to use silicon, which is used in the world of micro-engineering. What's more, creating an escapement using photoresist had the advantage of allowing for an extremely precise shape that had never been achieved before.

　However, another factor later contributed to the widespread adoption of silicon. At the time, Nivarox Fahr, a subsidiary of the Swatch Group, held the monopoly on balance spring production. As a result, other companies, shunned by Nivarox Fahr, began to turn their attention to silicon balance springs, which were easier to produce. Additionally, silicon balance springs were non-magnetic, resistant to shocks, and had the potential to improve the accuracy of mechanical watches by modifying their shape. Ulysse Nardin and Patek Philippe were the first to commercialize them. However, the Swatch Group also saw a future for silicon, and began using it at brands like Breguet, Blancpain, and Omega.

　One example is Breguet's new Type 20 (and Type XX). The ultra-high beat of 36,000 vph is made possible by a lightweight silicon escapement that requires no lubrication. Silicon has a specific gravity of 2.33 g/cm3, which is about one-third that of steel. This means that a silicon escape wheel has low inertia and minimizes torque loss. This is why a high beat can be achieved without increasing the torque of the mainspring. However, more importantly, it does not require lubrication. When Zenith's former CEO, Aldo Magada, first stated that the company adopted a silicon escapement, "By replacing the escapement with silicon, we are freed from the oil shortage that often occurs with high beat watches." This is also true of the Breguet Type 20.

　However, recently, there has been an increase in new attempts to take advantage of the properties of silicon. One such example is the "compliant mechanism," which takes advantage of the material's elasticity to combine multiple functions. This combines mechanical elements such as screws and springs with other structural components into a single part. This not only reduces the number of parts, but also makes the product lighter, which is a major benefit for small wristwatches.

　The pioneer of this movement was Girard-Perregaux's "Constant Escapement," announced in 2013 and re-released in 2024. This escapement uses the rotational motion of the gear train to bend a blade, and the resulting restoring force swings an anchor-like component back and forth, moving the balance wheel. It was a pioneer of constant-force escapements using the elasticity of silicon. However, it was also a pioneer of compliant mechanisms that combine multiple functions. As the photo shows, the blade, which acts as a constant-force device, the frame that supports it, and the anchor integrated with the blade are all combined into a single component. To allow the blade to bend and stretch sufficiently, the constant escapement is quite large, but its mechanism is quite simple. Incidentally, Ulysse Nardin's "Ulysse Anchor Escapement" and the "Zenith Oscillator" used in Zenith's "Defy Lab" also use compliant mechanisms that take advantage of the benefits of silicon. The latter in particular was the ultimate compliant escapement, with the balance wheel, hairspring, and anchor integrally molded from silicon, but productivity was problematic and it was never put into production.

　Regardless, the reason behind silicon's vast potential lies in its evolution as a material. Initially, silicon was prone to fracture and susceptible to moisture. Dr. Ludwig Oess, who was involved in the development of silicon at Ulysse Nardin, frankly admitted at the time of the announcement of the silicon balance spring that "early silicon performed poorly at low temperatures and was vulnerable to sudden temperature changes." Stefan Oess, who developed the constant escapement, also told me that when he began his research, "I thought silicon would break if bent. That's why I wanted to create a new escapement using existing materials." In response, various companies improved the physical properties of the silicon used in watches through surface oxidation treatments and other methods. By the mid-2010s, silicon components had become sufficiently practical.

　Omega's "Spirate System" is an amazing mechanism brought about by the evolution of silicon. Adjusting the rate by directly touching the balance spring is the same as with a conventional regulator. However, a delicate silicon balance spring cannot be clamped by a regulator in the first place. This is why all movements with silicon balance springs are free-sprung, without a regulator. In contrast, Omega has perfected an entirely new system that adjusts the rate by applying pressure to the outer edge of the silicon and changing the tension of the balance spring. The improved silicon material is undoubtedly the reason behind overcoming the watch industry's taboo of directly touching silicon.

　Another attempt is Louis Moinet's "Astronef Techno," which has a dial covered in silicon. The silicon used in watches is generally monochromatic because it undergoes a thorough oxidation process. However, silicon wafers with structural color inherently change color dramatically depending on the amount of light. This is the first watch to focus on the color of the silicon rather than its function. It is unclear whether other manufacturers will follow suit, but this also represents new possibilities for silicon materials.

　Silicon may seem like a commonplace material these days, but it's sure to become even more popular in the future, not only because the patent for silicon balance springs is about to expire, but also because larger silicon wafers are becoming more common.