Fraunhofer Institute for Microstructure of Materials and Systems IMWS
Fraunhofer Institute for Microstructure of Materials and Systems IMWS

Surface Texturing at the Micro- and Nanoscale

Interfacial properties such as wettability, biocompatibility, adhesion, and optical behavior are critical to the performance and functionality of materials and products across a wide range of technical applications. At Fraunhofer IMWS, our research group for biofunctional materials for health and environment has been advancing the optimization of product and surface properties through micro- and nanostructuring for many years.

We apply both direct structuring techniques, such as laser processing and electrochemical anodization, as well as micro- and nanostructured replication tools used in injection molding, hot embossing, and thermoforming. A key advantage of our patented technology lies in the ability to tailor material properties through precise surface design, without the need for additional additives or coatings.

This approach also helps to avoid lengthy and costly regulatory approval processes, as micro- and nanostructuring can be applied to already approved, chemically unchanged materials. As a result, companies benefit from significantly reduced time-to-market and lower development costs when introducing enhanced products.

 

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Optimizing Wettability Through Nanostructuring

A newly developed, patented nanostructuring process enables the precise tuning of interfacial properties, such as wettability and optical behavior of thermoplastic polymers. This is achieved through hot embossing using nanostructured molds based on nanoporous aluminum oxide templates

Enhanced Adhesion Through Hierarchical Structuring

The remarkable ability of geckos to adhere even to wet surfaces is largely attributed to the hierarchical, fibrillar structures on their feet, which maximize contact area. Inspired by this principle, we have developed an innovative method to improve polymer adhesion using hierarchical structuring via injection molding with micro- and nanostructured templates.

 

Nanostructured Membranes for Tissue Engineering

Porous aluminum oxide membranes, with their highly ordered and parallel pore structures, offer significant potential for cell culture and tissue engineering applications. Their tunable properties, such as pore diameter and membrane thickness. combined with tailored surface modifications, enable highly controlled and adaptable cell growth environments.

Micro-Structured Drug-Eluting Balloon Catheters

Conventional drug-coated balloon catheters release only a small fraction of the active agent at the target tissue, with much of the drug being lost during delivery through the bloodstream. To address this limitation, PTCA polyisoprene balloon catheters have been enhanced with transport-stable drug reservoirs created through laser microstructuring, improving targeted drug delivery and overall efficiency.

The targeted design of surface structures at the micro- and nanoscale enables significant improvements in the properties of biological materials. This opens new opportunities for medical applications, including dentistry, orthopedics, and regenerative medicine. 

By precisely engineering surface topographies, key material properties, such as biocompatibility (enhanced interaction with biological tissues and reduced risk of rejection), cell adhesion (promoting cell attachment and growth), surface energy (wettability and interaction with liquids), and mechanical performance (strength and flexibility) can be optimized. 

In addition, specially designed surface structures can also inhibit bacterial growth and thereby help prevent infections; they can also be used for the controlled release of drugs or growth factors (drug delivery systems). Efficient technologies for producing such micro- and nanostructures are just as valuable as comprehensive expertise in materials science for evaluating the resulting performance. 

 

Micro- and Nanostructuring Technologies

  • Nanostructuring via electrochemical anodization
  • Micro-laser processing using fs, ps, and ns laser systems
  • Hot embossing using laboratory presses (plate-to-plate and roll-to-plate)
  • Injection molding using ARBURG S320 and KraussMaffei KM200 systems
  • Thermoforming using Scheu-Dental BIOSTAR

Materials Science Characterization

  • Thermal analysis using differential scanning calorimetry (DSC)
  • 3D microstructure evaluation via laser scanning microscopy (LSM)
  • High-resolution imaging of micro- and nanostructures using scanning electron microscopy (SEM)
  • Wettability and surface energy analysis via contact angle measurements
  • Mechanical testing, including adhesion and bonding properties, using a texture analyzer
  • Spectroscopic analysis (UV-Vis, FTIR) to determine optical and absorption properties
  • Biocompatibility testing in accordance with ISO 10993