Electron beam technology can be used to reliably treat and functionalize surfaces. The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has now succeeded in creating non-stick coatings on plastic films by exposing them to low-energy accelerated electrons without the use of additional chemical crosslinkers. The institute will be exhibiting this film at BIOEurope 2022, from October 24 to 26, 2022, in Leipzig, at the Bio-Saxony booth no. 100.
Antifouling coatings prevent the colonization of undesirable organisms on surfaces. This is particularly necessary in shipbuilding, but is also important for medical devices and implants.
Low-energy electron beam technology (Ebeam) is a multifunctional tool with a wide range of applications that can be used specifically to modify surfaces. By using low-energy electron beam technology, surfaces can either be gently disinfected or sterilized, materials can be hardened in a surface-sensitive manner through cross-linking processes or surface properties, such as wettability, can be effectively modulated. Innovative surface-sensitive functionalization technologies guarantee that the material properties are retained, while at the same time the surface properties can be adapted. The use of low acceleration voltages (< 300 kilo-electron volts, keV) in low-energy, non-thermal electron beam processes guarantees very good material compatibility and sustainable material preservation.
What can be achieved in concrete terms?
Nic Gürtler, PhD student in the Medical and Biotechnological Applications department at Fraunhofer FEP, explains in detail: "Surface functionalization with accelerated electrons is fast and does not require any environmentally harmful chemicals. The low-energy accelerated electrons can be used to restructure, cross-link, break or form new chemical bonds close to the surface. When accelerated electrons hit a surface, various reactive species such as ions and radicals are formed, which play an important role in surface-specific modification processes. The atmospheric environmental conditions during the electron beam process can be individually adapted to the material and thus influence the desired degree of functionalization. Specifically, we were able to achieve a stable, non-toxic hydrogel coating on hydrophobic polyethylene (PE) and polyethylene terephthalate (PET) films."
The Ebeam-supported coating process Ebeam grafting offers the opportunity to equip materials with selective surface functions so that biocidal, biocompatible or antifouling properties can be achieved depending on the requirement profile. All process parameters of the non-thermal Ebeam-induced coating process can be individually monitored and modularly adapted. As part of various research projects at the Fraunhofer FEP, Ebeam grafting has already been successfully established as a two-stage coating process for equipping various hydrophobic plastic surfaces with antifouling attributes. The cell-repellent and protein-repellent surface properties resulting from Ebeam grafting can be used both in technical industries and especially in the field of biomaterial research as a starting point for the development of new medical devices or implants where uncontrolled biofilm formation is to be prevented. These ebeam functionalization processes can help to optimize dental implants in dental medicine, for example.
Low-energy electron beam technology, and therefore also beam grafting, is inline-capable, i.e. can be easily integrated into industrial processes on a customer-specific basis. The technology can also be implemented in roll-to-roll systems, for example to modify large flexible surfaces such as packaging.
Dr. Ulla König, Head of the Medical and Biotechnological Applications division, summarizes: "One of the core competencies of the Fraunhofer FEP is the development of special low-energy electron beam sources and systems for a wide range of applications. The focus of our work is on the technological development of individual, customer-specific system concepts."
