John Pethica has made significant contributions to methods for studying and characterising materials at the nanoscale. These include scanning tunnelling microscopy, to which John introduced the concept of forces acting between the instrument’s tip and the surface under study. This paved the way for atomic force microscopy, another extremely high-resolution analysis technique.

He invented and developed nanoindentation — a technique for testing the strength and other mechanical properties of tiny amounts of a material by pressing a hard tip into a sample. This method is now used by researchers around the world to investigate thin films and coatings in both industrial and academic laboratories.

Since 2007, John has worked as the Chief Scientific Adviser of the National Physical Laboratory, where he guides the organisation’s science and business strategies. He is a former Physical Secretary of the Royal Society, raising the profile of the applied sciences and shaping its policy on climate change during his term of office. In 2014, he received a knighthood for services to science.