Watches × Micro-Engineering
Half a Millimeter Wide: The Flexure Springs That Tell Patek’s Celestial When the Sun Rises
Elena Voss · July 13, 2026
Patek Philippe replaced the pivoting rack in the traditional sunrise-sunset mechanism with a LIGA-fabricated compliant flexure just 0.48 mm wide. Two ovoid cams encode Geneva’s latitude, a single lever synchronizes daylight saving corrections across hour hand, date, and sunrise-sunset scale, and three superimposed discs rotate at sidereal, lunar, and synodic rates. Six patents, 426 parts, 7.93 mm thick.