A New Method For Growing Watch Springs

Scientists at the Swiss Federal Laboratories for Materials Science and Technology (Empa) recently developed a new technique for growing watch springs to tiny specifications. As it turns out, the creation of watch springs is ripe with opportunity for new materials research.

The technique involves using photo-etching and electrochemical deposition into cold, aqueous solutions. Compared to drawing and winding Nivarox wires, this is a fairly unconventional method for manufacturing. For as long as watchmaking has been around, creating the balance springs has been one of the most difficult parts of the job. The wires must be drawn to a thickness in the hundredths of millimeters and wound and tempered to the exact hardness, ductility, and elasticity while compensating for environmental factors. Many substances change their properties during fabrication, so the Empa team decided to look to pure materials research as a way to find a means for fabricating balance springs that would remain stable.

They took silicon wafers (the same kind used for solar panels and computer chips), covered them in gold and a thin layer of light sensitive paint, and etched the shape of a spring into the wafer. The wafer was then dipped into a galvanic bath containing a salt solution from a metallic alloy — the spring acts as a cathode so that when an electric current passes through the bath, metal is deposited at the base of the spring. Once the spring is built up, it is dissolved from the mold and examined. After a bit of smoothing, the final spring is washed and sent to a lab for prototype production.

The electroplated springs are currently on display at the Laboratory for Mechanics of Materials and Nanostructures at the Empa campus in Thun, Switzerland. In the meantime, the first pilot tests are being wrapped up, and the team is beginning to work with Swiss watchmakers to see if their springs can hold up inside watch mechanisms.

[Thanks to Qes for the tip!]

25 thoughts on “A New Method For Growing Watch Springs

  1. This is kind of exciting that hackaday posted something like this.

    I went to school for 2 years to learn horology and met Stephen Forsey of Greubel Forsey, and have met and talked with some very prominent horologists.

    If anyone is seriously interested in the next generation of watch hairsprings, look up also LIGA technology.

    There is one American company that is extremely small making silicon hairsprings, called Firehouse Horology.

    https://firehousehorology.com/

    I myself am working on a handmade mechanical watch opus that may use one of their hairsprings someday, but I may make my own, from raw steel, and do bimetalic compensation balance. Just so I can say I made everything myself.

  2. This method can be applied to composite metals as well.

    Imagine building up a block of metal consisting of alternating layers of different metals, or (with photo etching) different layers in specific patterns.

    There’s a lot of opportunity for research here in materials science.

  3. “the creation of watch springs is ripe with opportunity for new materials research”

    You mean rife with opportunity? Ripe means ready for harvest. Rife means abundant. Neither seems to apply to the statement. Now, if it was buggy whips….

    1. I think “ripe” is the better word here, since it is “ready for harvest”. To me, “rife” has a negative connotation, as in an area is “rife with gangs and drugs”. Could be wrong though…

  4. Amazing …

    Amazing how it is done.

    Amazing, or rather enlightening, to realize that old mechanical clock mechanisms still have a future.
    I would have guessed that with the precision and simplicity of quartz movements watches with spring mechanism were doom to disappear.

    Interesting.

    1. They somewhat are as for 99% of use cases quartz is fine. Mechanical watches are just pretty vanity pieces like the supercars of the world. Though not one quartz watch has ever kept time on my wrist, never looked into why and not worn a watch for years now. The same watches always kept time for the rest of the family..

      Still have a place however as purely mechanical can work perfectly in environments electronic won’t (for example my wrist). Not sure how much call there really is for such things in the real world but they are too intresting to be allowed to die – If something can last for 100+ years with only a little care it can’t be a bad thing to refine and improve upon the design.

      1. Please if you must say it, use-cases. Avoid hate, hyphenate. (Please hyphenate use cases cases. Or is it please hyphenate use cases use cases? Or is it 99% of use boxes quartz is fine?)

      2. All my digital watches going back to that TI. LED watch in 1977 have kept very good time. A difference is the readout is so precise that it’s easy to see if it’s not on time.

        But then my Casio Waveceptor syncs up to WWVB every night, so even if there’s drift, it can’t go far in 24 hours. Those Longitude people would have loved it, except it needs a radio station to sync up. If they’d had radio back then, less need for a watch that keeps accurate time. Though the radio station needs a good clock.

        1. My old quartz ones would get hours out in a day sometimes usually 30 odd mins.. Not a small drift. But only if I wore them.. My family can and did use them for ages with no trouble. We always assumed it must be something to do with my bodies electric field – at the age I was not like I was playing with electronics that could create a drift (last time I used a quartz I was still something like 14, so going to school, clubs, the park friends houses etc).

          Not tried one since as if I ever need a watch I have a lovely mechanical one my Grandfather gave me so I could keep time.

          1. They say that the wrist keeps the watch a constant temperature, which of course is good to keep the crystal at the same freuqency.

            Maybe it was just a guess I read someone suggested.about the wrist, but constant temperature is good for crystals.

          2. I suppose being a very active child fluctuating temperatures could do it.. But I’d not expect the minor variations of body heat even under those conditions to make such a huge difference, surely can’t be more than a few degrees of variation unless you are really ill or feverish.

    2. Amazing, or rather enlightening, to realize that old mechanical clock mechanisms still have a future.

      Why? Some people still think swords are pretty neat. Some people are still making fire drills. Some people will always have obsessions with obscure and outdated technology

  5. There was a clockmaker in the 1720s who made clocks accurate to within a few seconds a month and one of his secrets was to use wooden gears rather than metal ones. The documentary was called “The search for Longitude”

    1. John Harrison, self taught English clockmaker. His real tricks in that were realizing how to orient the grain of the wood in the right orientation to take the least wear, and using a special wood that had, unlike almost all woods, an exceedingly high toughness and wear resistance- but was also naturally self oiling, called Lignum Vitae.

      Theres a lot more to the clock of his that still runs, I believe it was a grasshopper escapement. The man’s story and his singular tenacious insanity are captured beautifully in Dava Sorbel’s book “Longitude”. He is the reason timekeepers got temperature compensation springs- because he invented the bimetallic strip that allowed it, and by extension, modern meat thermometers, oven thermometers, and outside analogue thermometers with a hand- all possible because of him.

        1. Yup. He invented a fundamental mechanical technology with the brass steel bimetallic strip for temperature compensation that can be used to measure temperature directly if used in reverse and with a scale of measurement calibrated to it. It still works with only 1 part, probably will be used 2000 years from now. Gridiron pendulums on longcase clocks use the same tech for their rods- it keeps the length of the pendulum near constant regardless of temperature, keeping the period of swing of the pendulum consistently accurate for good timekeeping.

      1. If you enjoyed “Longitude” then I can highly reccomend “The Perfectionists: How Precision Engineers Created the Modern World” – by Simon Winchester. Like Dava Sobel, Winchester spins an excellent yarn, in this case about how we got to here, chapter by chapter he relates the people and processes which see an order of magnitude increase in precision.

  6. In the meantime, the first pilot tests are being wrapped up, and the team is beginning to work with Swiss watchmakers to see if their springs can hold up inside watch mechanisms…….

    I would have done that at the start. Before spending any money. This is how you set yourself up for failure. By failing to check if your good idea, is actually good.

    1. It’s all very well to say that, but, surprisingly enough, the experts can’t tell if your new device will hold up under physical stresses if it doesn’t actually exist.

      (I’d wager they did a lot of computer modeling and consulting with watchmakers beforehand, but that’s not a substitute for building the thing and testing it – and when you’re inventing the tools to invent the thing, there’s a lot of room for theory to go awry.)

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