scholarly journals The synergy between the insect-inspired claws and adhesive pads increases the attachment ability on various rough surfaces

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Yi Song ◽  
Zhendong Dai ◽  
Zhouyi Wang ◽  
Aihong Ji ◽  
Stanislav N. Gorb
Keyword(s):  
Rough Surfaces ◽  
Adhesive Pads ◽  
Attachment Ability

scholarly journals Insect wet steps: loss of fluid from insect feet adhering to a substrate

2013 ◽  
Vol 10 (78) ◽  
pp. 20120639 ◽  
Author(s):  
Alexander E. Kovalev ◽  
Alexander E. Filippov ◽  
Stanislav N. Gorb
Keyword(s):  
Surface Roughness ◽  
Fluid Flows ◽  
Solid Substrate ◽  
Fluid Loss ◽  
Adhesion Forces ◽  
Roughness Parameters ◽  
Fluid Absorption ◽  
Remarkable Effect ◽  
Adhesive Pads ◽  
Attachment Ability

Reliable attachment ability of insect adhesive pads is proposed to be due to pad secretion. It has been shown that surface roughness strongly reduces adhesion forces of insect pads. This effect has been explained by decreased contact area and rapid fluid absorption from the pad surface by rough surfaces. However, it remains unclear how the fluid flows on rough substrates having different roughness parameters and surface energy. In this paper, we numerically studied the fluid flow on rough substrates during contact formation. The results demonstrate that an increase in the density of the substrate structures leads to an increase in fluid loss from the pad: substrates with a fine roughness absorb pad fluid faster. Decreased affinity of the solid substrate to the fluid has a more remarkable effect on the fluid loss and leads to a decrease in the fluid loss. With an increase in the aspect ratio of the substrate irregularities (porosity), the fluid loss is decreased. The numerical results obtained agree well with previous observations on insects and experimental results on nanoporous substrata. The significance of the obtained results for understanding biological wet adhesives is discussed.

scholarly journals Porous substrate affects a subsequent attachment ability of the beetle Harmonia axyridis (Coleoptera, Coccinellidae)

2019 ◽  
Vol 16 (150) ◽  
pp. 20180696 ◽  
Author(s):  
Elena V. Gorb ◽  
Wiebke Lemke ◽  
Stanislav N. Gorb
Keyword(s):  
Recovery Time ◽  
Harmonia Axyridis ◽  
Plant Protection ◽  
Porous Membrane ◽  
Porous Substrate ◽  
Porous Sample ◽  
Significant Difference ◽  
Adhesive Pads ◽  
Attachment Ability ◽  
Insect Attachment

According to literature data, porous substrates can cause a reduction of insect attachment ability. We carried out traction experiments with adult ladybird beetles Harmonia axyridis on the smooth solid glass sample and rough porous Al 2 O 3 membrane to prove the primary effect of absorption of the insect pad secretion by porous media, rather than surface roughness, on the attachment force on the porous sample. With each insect individual, a set of five experiments was conducted: (1) on glass; (2) on the porous membrane; (3–5) on glass immediately after the test on the porous surface, then after 30 min and 1 h of recovery time. On the porous substrate, the forces, being similar in females and males, were greatly reduced compared to those measured on glass. A significant difference between the force values obtained in the first (before the test on the porous sample) and second (immediately after the experiment on the porous sample) tests on glass was observed. After 30 min recovery time, beetles completely regained their attachment ability. Females produced significantly lower forces than males in all experiments on glass: the differences are probably caused by the sexual dimorphism in the microstructure of their adhesive pads. The obtained results are of fundamental importance for further application in biomimetics of novel insect-repelling surfaces and in plant protection by using porous materials.

scholarly journals Insect attachment on crystalline bioinspired wax surfaces formed by alkanes of varying chain lengths

2014 ◽  
Vol 5 ◽  
pp. 1031-1041 ◽  
Author(s):  
Elena Gorb ◽  
Sandro Böhm ◽  
Nadine Jacky ◽  
Louis-Philippe Maier ◽  
Kirstin Dening ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Coccinella Septempunctata ◽  
Fold Reduction ◽  
Adhesive Pads ◽  
Highly Hydrophobic ◽  
Chain Lengths ◽  
Attachment Ability ◽  
Insect Attachment

The impeding effect of plant surfaces covered with three-dimensional wax on attachment and locomotion of insects has been shown previously in numerous experimental studies. The aim of this study was to examine the effect of different parameters of crystalline wax coverage on insect attachment. We performed traction experiments with the beetle Coccinella septempunctata and pull-off force measurements with artificial adhesive systems (tacky polydimethylsiloxane semi-spheres) on bioinspired wax surfaces formed by four alkanes of varying chain lengths (C36H74, C40H82, C44H90, and C50H102). All these highly hydrophobic coatings were composed of crystals having similar morphologies but differing in size and distribution/density, and exhibited different surface roughness. The crystal size (length and thickness) decreased with an increase of the chain length of the alkanes that formed these surfaces, whereas the density of the wax coverage, as well as the surface roughness, showed an opposite relationship. Traction tests demonstrated a significant, up to 30 fold, reduction of insect attachment forces on the wax surfaces when compared with the reference glass sample. Attachment of the beetles to the wax substrates probably relied solely on the performance of adhesive pads. We found no influence of the wax coatings on the subsequent attachment ability of beetles. The obtained data are explained by the reduction of the real contact between the setal tips of the insect adhesive pads and the wax surfaces due to the micro- and nanoscopic roughness introduced by wax crystals. Experiments with polydimethylsiloxane semi-spheres showed much higher forces on wax samples when compared to insect attachment forces measured on these surfaces. We explain these results by the differences in material properties between polydimethylsiloxane probes and tenent setae of C. septempunctata beetles. Among wax surfaces, force experiments showed stronger insect attachment and higher pull-off forces of polydimethylsiloxane probes on wax surfaces having a higher density of wax coverage, created by smaller crystals.

Infrared spectra of carbon monoxide on platinum, iridium and copper ; comparison of flat and rough surfaces

1981 ◽  
Vol 78 ◽  
pp. 927-932 ◽  
Author(s):  
F.J.C.M. Toolenaar ◽  
G.J. van der Poort ◽  
F. Stoop ◽  
V. Ponec
Keyword(s):  
Carbon Monoxide ◽  
Infrared Spectra ◽  
Rough Surfaces

OPTICAL PROPERTIES OF THIN FILMS ON ROUGH SURFACES

1983 ◽  
Vol 44 (C10) ◽  
pp. C10-363-C10-366 ◽  
Author(s):  
J. Vlieger ◽  
M. M. Wind
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Rough Surfaces

A Laboratory Device to Measure the Interfacial Phenomena between Rubber and Rough Surfaces

1999 ◽  
Vol 27 (4) ◽  
pp. 206-226 ◽  
Author(s):  
L. Garro ◽  
G. Gurnari ◽  
G. Nicoletto ◽  
A. Serra
Keyword(s):  
Rough Surfaces ◽  
Computer Software ◽  
Interfacial Phenomena ◽  
New Device ◽  
The Road ◽  
Constant Torque ◽  
Rubber Compounds ◽  
Simple Geometry ◽  
Tangential Forces ◽  
On The Road

Abstract The interfacial phenomena between tread rubber compounds and rough surfaces are responsible for most of the behavior of a tire on the road. A new device was developed for the investigation of these phenomena in the laboratory. The device consists of a fully instrumented road wheel on which a simple geometry specimen is driven. The possibilities offered by this device are to perform tests at constant slip or at constant torque on both wet and dry surfaces, with complex cycles. The machine allows the measurement of slip, tangential forces, and temperature on the specimen, and computer software adds the possibility of applying Fourier analyses on force, road wheel speed, and specimen speed data. Other possibilities offered by the road wheel are to change the road surface, the load on the specimen, and the water rate. The description of a complete experiment is detailed in the paper showing the correlation of data with actual tire performances.

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