Prakt. Met. Sonderband 38 (2006) 471 
ANTIADHESIVE METAL SURFACES BASED ON 
HIERARCHIAL TOPOGRAPHY 
P. Léthman', P. Wagner? K. Tittes®, V. Eigenbrod?, C. Neinhuis’ 
'Dresden University of Technology, Institute of Botany. 
Bionics, BioNanotechnology and Multifunctional Surfaces Research Group. 
Dresden, Germany 
’Rhenotherm GmbH 
Kempen, Germany 
*Nehlsen BWB-Galvanik Dresden GmbH & Co. KG 
Dresden, Germany 
ABSTRACTS 
Antiadhesive metal surfaces find applications in almost every branch of industry and 
are of crucial importance when sticky, possibly high-viscosity fluids are transported in 
pipelines, mixed in vessels or come in contact with surfaces during processing. Low 
adhesion forces between the surface and the surrounding medium can be achieved 
by altering surface topography and chemistry for each special case. The ideal 
surface structure which leads to the highest degree of anti-adhesive properties is 
believed to be a hierarchial surface structure coated with a hydrophobic component if 
the surface is wetted by aqueous liquids 
Our approach lends itself from biological surfaces in nature i.e. plant surfaces which 
show similar structural features as described above. The plant surface topography 
can be transferred upon metals such as copper, stainless steel and aluminum. Here 
the hierarchial structure is composed of a microstructure which is covered by a 
nanostructure and a coating which ideally is long-time stable. Traditionally 
conventional polymers are used as coatings but also biomolecules such as lipids and 
proteins are applicable. For example the so called tetraetherlipids can be isolated 
from the membranes of archae bacteria which live under harsh conditions such as 
high temperature and acidic environment which is believed to account for their 
excellent stability. 
Moreover, antiadhesive properties can be characterised by measuring the force 
required for separating an adherent from the surface to which it adheres. 
Conventional tensile testing machines can be used for this purpose. Additionally, 
long-term outdoor durability testing will make the picture complete concerning the 
application potential of antiadhesive surfaces. 
INTRODUCTION 
Adhesion phenomena are complex and in many cases undesired sideeffects in 
manufacturing and processing. Surfaces with antiadhesive properties find their use in 
such different fields as pharmaceutical, food, microelectronic, rubber and tire.