Open Access Articles- Top Results for Achim Leistner

Achim Leistner

File:Silicon sphere for Avogadro project.jpg
Achim Leistner at the Australian Centre for Precision Optics, holding a 1 kg, single-crystal silicon sphere for the Avogadro project

Achim Leistner is an Australian optician of German origin.[1] He is the master optician of the Avogadro project, an international effort to define the Avogadro constant with maximum precision. He was asked to join the project from retirement as it was deemed that his expertise and craftsmanship were essential for the success of the project.[2]

Leistner has made his career in the precision crafting of specialized optics. The Avogadro project needed a silicon sphere made to as high a precision as possible. The research team searched the world for manufacturing options and found Leistner's precision in handcrafting spheres superior to any machine. In addition to precision instruments, Leistner uses his hands to feel for irregularities in the roundness of the sphere.[1] The research team has called his extraordinary sense of touch "atomic feeling".[3]

Leistner is in his seventies and has not found an apprentice who can match his precision. Once he retires from the project, the Avogadro team hopes that machines will have advanced sufficiently to match Leistner's capabilities.[1]

Leistner holds certificates in precision optics, geometrical optics, optical design drawing, and mathematics from Optic Carl Zeiss Jena Technical College. He has served as a member of the Australian Optical Society and on international conference working committees for SPIE and the Optical Society of America.[4]


  1. 1.0 1.1 1.2 Jonathon Keats: The Search for a More Perfect Kilogram. Wired, 09.27.11.
  2. Devin Powell: Roundest objects in the world created. New Scientist, 1 July 2008.
  3. BBC: Precision: The Measure of All Things, episode 2: Mass and Moles. Television program aired 4 July 2014 in the UK.
  4. Stanford Who’s Who: Achim Leistner – Research and Development – Stanford Who's Who Certified. June 11, 2013.