Humberto Fernández-Morán

Humberto Fernández-Morán

The Venezuelan research scientist Humberto Fernández-Morán (1924-1999) invented the diamond knife (diamond scalpel) and significantly advanced the development of electromagnetic lenses for electron microscopy based on superconducting technology.


Humberto Fernández-Morán Villalobos was born in Maracaibo, Venezuela on February 18, 1924.

He studied medicine at the University of Munich and graduated summa cum laude in 1944. He also studied at the George Washtington University in the United States.


Diamond knife

Fernández-Morán invented the diamond knife in 1955. You can read more about this further down in this page.

Electron microscope

Fernández-Morán contributed to the development of the electron microscope.

Diamond knife + ultramicrotome

He was the first person to use cryo-ultramicrotomy. During a flight in an airplane over Venezuela he saw the smootlhy reoccuring flow system in a waterfall, and this inspired him to take his diamond knife invention and combine it with an ultramicrotome to improve the ultra-thin sectioning of electron microscopy samples.


Fernández-Morán helped advance the field of electron cryo-microscopy.

The RV-1 nuclear reactor

In 1957, Fernández-Morán was appointed supervisor for the first Venezuelan research nuclear reactor. This was the RV-1 nuclear reactor; one of the first nuclear reactors in all of Latin America.

The Venezuelan Institute for Neurological and Brain Studies

Fernández-Morán founded the Venezuelan Institute for Neurological and Brain Studies.

Minister of Science

Fernández-Morán was Minister of Science in Venezuela during the last year of Marcos Pérez Jiménez´s presidency. When Pérez was deposed in a coup in 1958, Fernández-Morán fled from Venezuela.

Career outside Venezuela

  • Fernández-Morán worked with NASA for the Apollo Project.
  • He taught at several different universities, including MIT, University of Chicago and Stockholm University.

Diamond knife

In 1955, Fernández-Morán invented the diamond knife; an especially sharp knife where the edge is made from diamond. Diamond knifes, also known as diamond scalpels, are used by medical doctors and scientific researchers for tasks where an extremely sharp edge is required. One notable area where diamond knifes have become essential is refractive surgery and certain other types of eye surgery.


For certain medical and scientific applications, a metal microtome knife or a razor blade will be too dull. In 1950, Latta and Hartmann discovered that the egde of broken glass cut be utilized to cut thin sections for electron microscopy, and glass knives were then created for this purpose. Using them was difficult, however, and the glass also became dull very quickly, especially when cutting hard materials.

Fernández-Morán discovered that gem-quality diamond could be used to create a knife better suited for ultramicrotomy. Diamond is the hardest known material in the world and Fernández-Morán´s diamond knife did not become dull as quickly as a glass knife.

Making a diamond knife

  • It is common to use natural diamond gemstones of great purity and regular crystal structure.
  • During the grinding process to make the knife, it is not unusual to reduce the stones by up to 50% of their original weight.
  • The diamond blade is mounted into a soft metal shaft, before being polished to achieve a sharp edge.
  • The shaft is mounted in a metal through (“the boat”) and secured with epoxy plastic or similar.

A diamond knife typically cost several thousand United States dollars to purchase.

Personal life

Fernández-Morán´s wife Anna was Swedish. Together, they had two daughters: Brigida Elena and Verónica. Fernández-Morán died in Stockholm, Sweden in 1999, aged 75. His ashes rest in >Cementerio Luxburg-Carolath in Maracaibo, the town where he was born.

Examples of accolades

  • The John Scott Award (for inventing the diamond knife)
  • Knight of the Order of the Polar Star (Swedish: Kungliga Nordstjärneorden)
  • Claude Bernard Medal, University of Montreal
  • Cambridge annual Medical Prize