Antiviral cleaning and disinfection technologies

Results from one year of anti-corona research

The Fraunhofer-Gesellschaft is contributing to the fight against the pandemic by funding so-called anti-corona projects from the medical and health sectors. Fraunhofer IFAM has been researching antiviral coatings, disinfecting or sterilizing treatment processes for indoor air, as well as concepts for automated cleaning and disinfection in public transport using service robots.

Inactivation of viruses in indoor air

The »Virus-Grill« apparatus developed by Fraunhofer IFAM can reduce the activity of viruses in indoor air by exploiting their temperature sensitivity. Heating the viruses and keeping them at inactivation temperature destroys their active envelope components and inactivates them. The viruses are then no longer infectious or capable of reproduction. Before the treated air is returned to the room, it is cooled down to near room temperature. The innovation: The recovered heat is used within in the system to heat air drawn in; this makes continuous process operation extremely energy-efficient.

Mobile and energy-efficient superheated steam sterilizers

Hot steam sterilization is essential for hygienic medical care. Previously, mobile and off-grid sterilizers for use in pandemic crises and humanitarian aid did not exist. Together with research partners, Fraunhofer IFAM has developed a mobile, compact and battery-poweredsterilizer. Thanks to the capillary evaporator principle, the unit is energy-efficient and ready for operation very quickly.

Mobile disinfection robot

To interrupt the transmission paths through contaminated surfaces in public areas, Fraunhofer IFAM developed an autonomous robot for the automated cleaning and disinfection of public transport as part of “Mobile Disinfection” (MobDi). Cramped access and obstacles such as gaps and steps already pose a major challenge for autonomously navigating systems. In addition, there are complex requirements for automated cleaning in terms of accessibility as well as different materials and shapes of seat cushions, handles, tables or windows. The resulting robot has a modular design and uses industry-standard interfaces, so that the developed technologies can be specifically adapted to the application needs.

Demonstrating antimicrobial effects

As part of the anti-corona projects, Fraunhofer IFAM has further expanded its analytical methods for bioanalytics in order to verify the effectiveness of antiviral or antibacterial surfaces and disinfection processes using efficient, objective and meaningful test methods.

Material with antimicrobial effect

In order to reduce the microbial load of contaminated surfaces through photocatalytic active coatings, a novel material composition was developed in the “COVID-DEKONT” project. By combining copper-doped titanium dioxide with phyllosilicates, an effect can be achieved that brings the microorganisms more effectively into contact with the catalysts and accelerates their inactivation.

The copper-doped photocatalyst can be dispersed in a PU coating system or compounded into thermoplastic polymers. These polymers can be easily extruded into filaments for 3D printing of complex components.

Fill contents of the photocatalyst complex of around 35 percent by weight in the PU coating and 50 percent by weight in the polymer achieve very good antibacterial and antiviral degradation results. Within two hours, a degradation rate of more than 80 percent can be achieved compared with the control components, both under UV light and with a light source similar to sunlight.