Léonard was born in Sion, Wallis. He received a BSc in Chemical Engineering from ETH Zurich in 2015 and a MSc in Chemical and Bioengineering from the same institution in 2017. He carried out his master thesis on the automated synthesis of perovskite nanocrystals using microfluidic reactors. He then went to do an internship at the London Center for Nanotechnology (UCL) as part of the i-sense research programme to develop novel nanomaterials for lateral flow assays. His research interests lie in the development of electrochemical biosensors for rapid diagnostic tests.