Geckos, insects and spiders do even better: They stick to walls and ceilings and move along them. Hair-like fibrils covering their feet allow these animals to not only "stick" headfirst to glass and smooth surfaces but also move along walls with woodchip wallpaper due to the fact that the hair-like fibrils branch out further into even finer structures. Scientists at INM – Leibniz Institute for New Materials will now reproduce such "hierarchical" structures in a new project granted recently by DFG.
sticking like a gecko
copyright Bellhäuser, only for use relating to this release
The project will join forces between two INM groups – Functional Surfaces (led by Prof. Arzt) and Structure Formation (directed by Dr. Kraus).
For this purpose, the scientists will test the structures for their adhesive force using specifically developed measurement methods. In order to understand why hierarchical structures provide a better adherence, the scientists also use computer-based models. "In this project, we seek to find out the best way of developing hierarchical structures, and we seek to analyze what these structures are able to do – with this we aim to understand why adhesion to rough surfaces is possible at all," explains Eduard Arzt, the Scientific Director of INM and Head of the Program Division "Functional Surfaces".
Basically, the principle of gecko adhesion is known. It is based on many thin hair-like structures with varying diamteres which provide a better adherence than thick structures. "Imagine a brush, whose bristles branch out downwards getting thinner and thinner," explains Tobias Kraus, Head of the Junior Research Group "Structure Formation at Small Scales". "With their rough bristles, they sweep off big stones. In order to remove fine dust or sand, they sweep with less pressure so that the fine bristles catch the dust," says Kraus. And the same applies to the gecko: The animal uses fine fibrils for fine unevenness and rough fibrils for rough unevenness.
"At the present state of the art, it is no longer a problem to fabricate structures with only one ‘fibril size'," says Arzt. For this purpose, the scientists use a molding technique. A liquid polymer is filled into a template of the "fibrils", where it hardens. The finished cast is then removed from the template. The result is a surface on which "fibrils" of the same size are arranged regularly.
With a new method, the scientists also seek to fabricate a branching into even finer fibrils. "The challenge is to produce a regular and narrow-spaced structure of these finest branches in the template," says the Chemical Engineer Kraus. Layer by layer, the scientists thus receive even more branched structures, starting with the thickest bristle.
Contact:Dr. Tobias Kraus
INM – Leibniz Institute for New Materials, situated in Saarbrücken/Germany, is an internationally leading centre for materials research. It is a scientific partner to national and international institutes and a provider of research and development for companies throughout the world. INM is an institute of the Scientific Association Gottfried Wilhelm Leibniz and employs around 190 collaborators. Its main research fields are Chemical Nanotechnology, Interface Materials, and Materials in Biology.
Dr. Carola Jung | idw
Breakthrough in nanoresearch - Quantum chains in graphene nanoribbons
09.08.2018 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt
UNH Researchers find seed coats could lead to strong, tough, yet flexible materials
08.08.2018 | University of New Hampshire
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.
Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
14.08.2018 | Information Technology
14.08.2018 | Life Sciences
14.08.2018 | Life Sciences