Surface engineering at HE-Arc: pushing the boundaries of surface coatings

The Surface Engineering Competence Group at Haute École Arc (HE-Arc) combines applied research, engineering education, and industrial support with the aim of meeting the specific needs of businesses. Specializing in surface treatments, the group develops numerous functionalities, whether to protect, lubricate, make surfaces biocompatible, or customize the appearance of components.

The group stands out for its specialization in small components, a strategic niche for watchmaking, medtech, and machining tools. Its expertise is based on two technological pillars: vacuum deposition (PVD, ALD) and liquid phase treatments (electroplating, anodizing, electropolishing). For thirty years, it has been developing decorative and functional coatings, working on colors, protection against wear and corrosion, dry lubrication, hydrophobicity and, more recently, improving the biocompatibility of surfaces. This research is part of an industrial support approach in which each project is tailor-made according to the customer's specifications and draws on expertise in characterization to develop a specific surface treatment or coating.

Concrete projects

The group carries out around ten projects per year, most of which are funded by Innosuisse-type funds. It was during one of these Innosuisse projects that Alliance first collaborated with the Surface Engineering group on a partnership involving PVD coatings for cutting tools, which led to a fruitful collaboration with a Jura-based company specializing in this field.

Another notable example of the projects carried out by the HE-Arc group is the development of flexible implantable electrodes for brain stimulation, particularly in the treatment of Parkinson's disease. Commercial electrodes, based on precious metals such as iridium or osmium, are expensive and bulky. The group has designed an alternative on a silicone support, with an ultra-thin metal layer, reducing the amount of material and the cost. The prototype has been validated in the laboratory and then industrialized by the company that initiated the project.

Another internal project solved a major technical challenge: the electropolishing of Nitinol cardiovascular stents produced using 3D printing. These stents, manufactured from powders, had detachable particles on their surface, posing a risk to patient safety. The group developed an electropolishing process using electrolyte baths and specially adapted electrodes, enabling uniform polishing and the removal of particles. This work has opened up a new field of activity: the environmentally friendly electropolishing of various alloys (steel, bronze, titanium, gold, silver) using "soft" solvents (DES — Deep Eutectic Solvents), which are biodegradable and biocompatible, replacing strong acids and harmful solvents such as methanol. These innovative solvents, considered "soft chemistry," not only deburr 3D-printed metal parts, but also achieve a mirror finish on conventional parts, a major advance for the medical and watchmaking industries.

Research and development serving industry

The Surface Engineering Competence Group embodies a vision of innovation focused on industry, not only by developing technologies, but also by making them accessible, applicable, and environmentally friendly. The group's expertise is based on characterization skills such as metallographic, topographic, and chemical composition analyses, as well as mechanical, optical, tribological, and corrosion testing.