Surface technology for tailored material properties

Techniques and processes for the functionalization and modification of surfaces

The experts at Fraunhofer IFAM have extensive knowledge in the targeted modification and functionalization of surfaces. This includes cleaning and activation as well as appropriate pre-treatment prior to painting and bonding. The requirements for technical surfaces are diverse and depend on the respective application. For example, work is being done on developments for corrosion-protective, flow-optimized, ice- and dirt-repellent, antibacterial, biocompatible or with anti-fouling properties. Specific tribological, optical or electrical requirements as well as the sensing of surfaces can also be served.

Here you will find an initial overview of the processes and functionalizations that our scientists have mastered and that we use to address your specific questions.

Wet-chemical surface treatments


Contamination of surfaces with auxiliary materials used in production processes, such as release agents or lubricants, is a frequent problem for the subsequent bonding or coating of components or products. For surface treatment of metals, wet chemical pretreatment still plays a key role in industrial applications – e. g. aerospace and automotive engineering: cleaning (removal of contaminants from previous process steps), pickling and deoxidation (removal of undefined layers, adjustment of surface roughness), and protection and activation (conversion coatings, anodizing).

In addition, wet chemical processes can be used to produce different functional coatings, which can provide specific properties, for example biocompatibility, corrosion protection, wear protection or electrical insulation. Further advantageous properties can also be achieved by combining different treatment processes like wet-chemical processes with plasma and paint technology.

Dry chemical processes: Plasma technology, VUV technology and abrasive technologies


When a pretreatment process is to be developed without the use of chemicals, the institute draws on its extensive expertise in plasma technology, VUV technology and abrasive technologies. The workpiece to be cleaned is exposed to a plasma or the vacuum ultraviolet (VUV) radiation of a plasma, which removes organic contaminants from the surface. Heavy contaminants, such as large particles and thicker contamination layers, can be removed by technologies with abrasive effects (e. g. CO2 snow jets, vacuum suction jets, laser ablation) for coarse cleaning.

Dry chemical processes such as plasma and laser technology can also be used to achieve a wide range of surface functions such as adhesion, release, corrosion protection, electrical insulation, and water and dirt repellency. Fraunhofer IFAM has also developed coating systems using plasma technology which enable simple, non-destructive and release agent-free demolding of FRP components.

Functional paints and coatings


Surface protection, including corrosion protection, and decoration of objects have always been the classic tasks for paints and coatings. In recent years – due to new technical possibilities and raw materials – a wide range of opportunities have opened up to give consumer goods innovative functions by means of coating technologies. Fraunhofer IFAM offers particular expertise in a wide range of applications like flow resistance reducing, anti-icing, anti-fouling, or corrosion protection coatings. Recent developments have produced self-healing coatings with microencapsulated corrosion protection inhibitors. Now, biocompatible and antibacterial coatings have become the focus of our researchers. Another recent field of research is the development of barrier coatings for various gases e.g. hydrogen, oxygen and water vapour as well as corroding gases such as hydrogen sulfide.

Printing technologies


In industrial production, there is a great need for functional structures to optimize the properties of a wide variety of components. For targeted functionalization, specific structures can be applied precisely to the required location on a component using printing processes. Sensors or electronic components can thus be integrated into existing products and can provide additional or completely new properties. The Center for Networked Surface and Coating Technology also focuses on decoration with printing or other edge-sharpening technologies.

Corrosion protection


Corrosion protection is an important topic at Fraunhofer IFAM and handled interdisciplinary and comprehensively. Industrial branches such as aircraft construction, shipbuilding, wind energy, automotive engineering, and the electronics industry, to name a few, already benefit from the know-how of our experts in the fields of interfacel and adhesion research, paint technology, as well as plasma and laser technology and polymer encapsulation and analysis.

Specific challenges in the field of corrosion protection can be analyzed using the latest analytical techniques (electrochemical, electron microscopic, surface analysis, etc.) and tailored corrosion protective measures can be developed using a wide range of technologies. The corrosion testing laboratory at Fraunhofer IFAM is accredited according to DIN EN ISO/IEC 17025 and, in addition to salt spray testing (DIN EN ISO 9227), offers a variety of other corrosion tests as a service. Parts of the laboratories at the Bremen site are also recognized as independent testing laboratories in accordance with the Nadcap system required by the aviation industry (see "Chemical Processing" in the aviation industry according to Nadcap). In addition, storage and weathering facilities are available under near-operational environmental conditions on the deep-sea island of Heligoland, in List on Sylt, at the "Alte Weser" lighthouse and on the Brocken in the Harz mountains.

Biofunctional surfaces and bioanalytics


Surfaces play a central role in nature and also in almost all technical applications. In the case of implants, for example, the aim is to ensure a high level of biocompatibility through the binding of selected molecules, while at the same time providing protection against pathogens. The targeted binding of proteins or cells to surfaces is also of particular relevance in medical diagnostics.

At the same time, however, there are many areas of application for surfaces where interaction with biological materials is undesirable. These include the non-specific adsorption of proteins on pharmaceutical packaging, on implants, in the area of sensor surfaces or on technical surfaces such as ship hulls ("antifouling").

In interdisciplinary research projects, the issues outlined above are addressed both across departments at Fraunhofer IFAM and with national and international partners. Analytical, microbiological or cell biological tests are carried out to validate the developed materials or surface modifications in accordance with existing standards.

Cross-technology consulting for the realization of surface functions


At Fraunhofer IFAM, the cooperation of experts from different technical disciplines supports new ways and solutions for the development of functional surfaces. It often makes sense to combine different treatment processes in order to realize the desired surface properties. We will be pleased to advise you on the possible approaches for your individual problem and company-specific requirements.