Achim Leistner is an Australian optician of German origin. 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.
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. The research team has called his extraordinary sense of touch “atomic feeling”.