Title: Deposition of biopolymers by cold gas spray

Abstract

The low-pressure cold spray process is a technique originally developed for the fabrication of industrial metallic coatings. Hence, it is not currently useful for the preparation of polymer coatings unless the introduction of some modifications into the gun is considered. Polymer coatings can have very interesting functional applications in the biomedical field, as they can provide bioactivity and enhance biocompatibility of metallic implants. Given the interest in this type of coatings for biomedical applications, some efforts have been performed by our research team to understand the thermo-kinetic conditions that some biopolymers undergo while they are processed by low pressure cold spray. This knowledge has allowed us to introduce some modifications into the cold spray gun design to enable this technique for the fabrication of polymer coatings. The results of our research suggest that dimensions of the cold spray gun nozzle are crucial to modify the kinetic and thermal history of the in-flight particles in the process; those changes can also be optimized to promote the formation of the coatings. Although, further efforts must be endeavor to understand the mechanisms acting upon the polymer particles during impact to fully understand the bonding mechanisms involved.