Beetles, cockroaches, and ants will have a harder time walking on facades or air conditioners in the future – thanks to the bio-inspired, anti-adhesive surfaces Prof. Dr. Thomas Speck, Dr. Bettina Prüm, and Dr. Holger Bohn are developing together with the Plant Biomechanics Group of the University of Freiburg.
Source: Plant Biomechanics Group Freiburg
The team studied plant surfaces in order to determine what influence cell form and microstructure as well as surface chemistry exert on the adhesion behavior of insects.
The researchers conducted adhesion experiments in which Colorado potato beetles walked across differently structured plant surfaces as well as replicas made of synthetic resins. The team used a highly sensitive sensor to measure the traction forces of the beetles on various surfaces. They discovered that wavy or strongly curved cells can increase the adhesive powers of beetles, whereas microstructures composed of wax crystals or cuticular folds reduce them.
The latter are tiny folds in the cuticle, a protective layer on the surface of the leaf resembling polyester. The beetles had the hardest time walking on surfaces with cuticular folds with a height and width of approximately 0.5 micrometers and a spacing of between 0.5 and 1.5 micrometers. “That is the perfect anti-adhesion surface. The insects slip off of it much easier than off glass,” says project director Thomas Speck.
The cuticular folds reduce the contact area between the adhesive hairs on the beetles’ legs and the plant surface. Unlike on more coarsely structured surfaces, the beetle can’t dig its feet firmly into the cuticular folds. Thus, the microstructure of the surface has a stronger effect on the adhesion of the beetle than the cell form.
The team also took contact angle measurements to investigate the wettability of the various surfaces. The researchers used hydrophobic and hydrophilic artificial moldings of the microstructured plant surfaces in order to study the influence of the surface chemistry on surface wettability and the beetles’ walking behavior. Much like wax crystals, cuticular folds are very good at repelling water. In contrast to the wettability, which depends on both the microstructure and the surface chemistry, the walking behavior of the beetles is not influenced by the surface chemistry. This means that the beetle’s adhesive power depends solely on the physical microstructure of the surface.
Speck and his team published their findings in the current issue of the journal Acta Biomaterialia. In the future, the anti-adhesion surfaces could be used to line the ventilation pipes of air conditioners, which are often teeming with cockroaches and other insects. In addition, they could also be applied to facades and window frames to prevent insects that move predominantly by walking from entering the house and invading the cupboard and medicine cabinet. “This aspect is particularly important in the tropics,” says Speck.
The fundamental biological research on anti-adhesion surfaces will be conducted from now on at the Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), where the researchers will also press ahead with the material development and begin constructing a prototype. “We also want to collaborate with our colleagues at FIT to make the artificial surfaces adaptable to the hair structure of different groups of insects, for instance by means of stretching or shrinking,” explains the project director.Background information:
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences