https://phys.org/news/2018-10-high-performance-components-electroplating.html

By now, the production in the Empa lab has outgrown the first pilot tests. On a regular basis the electroplated springs are delivered to the R&D department at a major Swiss watchmaker, where they are fitted in prototype watch mechanisms. The watches run. However, there is still work to do on their accuracy and long-term stability.

Only a few years ago, Empa had to rely on partners to take care of certain process steps. Meanwhile, the knowhow for the entire production process is pooled in Michler's lab. Laetitia Philippe, who oversees the production of the springs, explains the production steps. The base material is a silicon wafer like the ones used to produce computer chips and solar cells. This wafer is initially coated with a conductive gold layer and, later on, a thin layer of light-sensitive paint. The shape of the spring is then projected onto it and the illuminated parts of the paint are etched out. Now the desired metallic alloy can be electroplated onto the conductive gold base.