The aim of the project is to develop an innovative technique for the functionalisation and treatment of materials by cold projection of a gas loaded with powder. This technique known as cold spray will be implemented and combined with the supercritical nitrogen jet technique to form an original and unique hybrid jet in Europe. The hybrid process is able to clean, decay, prepare a surface and deposit a technical coating that can have a multitude of functions. For example, in additive manufacture, a protective metal layer may be deposited against corrosion, anti-wear or a reactive anti-bacterial layer, moisture absorbent, conductor of electricity or heat. It is also possible to deposit particles with anti-inflammatory biological functions (prostheses) or biocompatible precursors to promote the growth of vascular tissues of a heart valve, for example. The combination of these two techniques will be the subject of research and development on the study of the processes of mixing and projection of powders in a flux of nitrogen gas in the extreme atmosphere of temperature (between + 500 °C and — 178 °C) and pressure (between 50 and 3 500 bar). The experiments will be carried out on an installation consisting of a cold spray upgrade, hybridisation systems and equipment for measuring and characterising the hybrid jet.