Biological Micro- and Nanotribology: Nature’s SolutionsEver since the genesis of life, and throughout the course its further evolution, Nature has constantly been called upon to act as an engineer in solving technical problems. Organisms have evolved a variety of well-defined shapes and structures. Although often intricate and fragile, they can nonetheless deal with extreme mechanical loads. Some organisms live attached to a substrate; others can also move, fly, swim and dive. These abilities and many more are based on a variety of ingenious structural solutions. Understanding these is of major scientific interest, since it can give insights into the workings of Nature in evolutionary processes. Beyond that, we can discover the detailed chemical and physical properties of the materials which have evolved, can learn about their use as structural elements and their biological role and function. This knowledge is also highly relevant for technical applications by humans. Many of the greatest challenges for today's engineering science involve miniaturization. Insects and other small living creatures have solved many of the same problems during their evolution. Zoologists and morphologists have collected an immense amount of information about the structure of such living micromechanical systems. We have now reached a sophistication beyond the pure descriptive level. Today, advances in physics and chemistry enable us to measure the adhesion, friction, stress and wear of biological structures on the micro- and nanonewton scale. Furthermore, the chemical composition and properties of natural adhesives and lubricants are accessible to chemical analysis. |
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Page xi
... .1 Photoelectron Spectroscopy . 5.3.3 Infrared Spectroscopy 171 5.3.2 Auger Electron Spectroscopy . 173 175 5.3.4 Low - Energy Electron Diffraction . 176 6 . Nanoscale Probe Techniques 179 6.1 Scanning Tunneling Microscope Contents ΧΙ.
... .1 Photoelectron Spectroscopy . 5.3.3 Infrared Spectroscopy 171 5.3.2 Auger Electron Spectroscopy . 173 175 5.3.4 Low - Energy Electron Diffraction . 176 6 . Nanoscale Probe Techniques 179 6.1 Scanning Tunneling Microscope Contents ΧΙ.
Page 8
... energy by friction and inertia . When the motion of the flat sample is reversed , the spring expands until the initial position is reached . Provided that there is adhesion between ball and flat the spring expands further . The contact ...
... energy by friction and inertia . When the motion of the flat sample is reversed , the spring expands until the initial position is reached . Provided that there is adhesion between ball and flat the spring expands further . The contact ...
Page 17
... energy minimization ( see Fig . 2.9 ) : Ас = π R K ( Fn + 677R + √ / 127¬RF2 + ( 67¬R ) 2 ) ] * ( 2.23 ) with the interfacial energy , representing the action of adhesion . When no normal force is applied ( F = 0 ) a finite value of ...
... energy minimization ( see Fig . 2.9 ) : Ас = π R K ( Fn + 677R + √ / 127¬RF2 + ( 67¬R ) 2 ) ] * ( 2.23 ) with the interfacial energy , representing the action of adhesion . When no normal force is applied ( F = 0 ) a finite value of ...
Page 19
... , the values for silica were used ; see Table 2.1 . This shows that the JKR model applies , since the radius and surface energy are large . The ball , however , is not perfectly hard because of the water 2.3 Mechanical Properties 19.
... , the values for silica were used ; see Table 2.1 . This shows that the JKR model applies , since the radius and surface energy are large . The ball , however , is not perfectly hard because of the water 2.3 Mechanical Properties 19.
Page 20
... energy should be treated with the DMT model [ 62 ] . • While the JKR model accounts for short - range attraction forces , the DMT model covers long - range attraction . • Data obtained with scanning probe techniques can be analyzed also ...
... energy should be treated with the DMT model [ 62 ] . • While the JKR model accounts for short - range attraction forces , the DMT model covers long - range attraction . • Data obtained with scanning probe techniques can be analyzed also ...
Contents
7 | |
Biological Frictional and Adhesive Systems | 78 |
Frictional Devices of Insects | 129 |
Microscale Test Equipment 153 | 152 |
Nanoscale Probe Techniques | 179 |
Microscopy Techniques | 193 |
Samples Sample Preparation | 223 |
Friction | 243 |
Material Properties 251 | 250 |
A Contact Models | 259 |
List of Symbols | 273 |
Index | 299 |
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Biological Micro- and Nanotribology: Nature’s Solutions Matthias Scherge,Stanislav Gorb No preview available - 2010 |
Common terms and phrases
adhesion adsorbed animals applied asperities atoms attachment pads ball and flat beam behavior Biol biological body byssus cantilever capillary action capillary bridge capillary force cartilage cells chemical collagen contact area cuticle decrease deflection deformation distal distance double-layer elastic electron elytra endomysium energy epicuticle epidermal flat sample fluid force curve friction force function glands Hertz humidity hydrophilic hydrophobic increasing indentation insect interaction interlock layer Lett lubrication material mbar measured method microscopy microtrichia molecular molecules monolayer muscle nanometer normal force obtained oscillation oxide Phys plant probe profilometer protein pull-off pull-off force range roughness scanning sclerites secretion Sect sections sensor shear shown in Fig shows silicon SILICON model system sliding velocity smooth solid specimen staining stick/slips structure substrate surface synovial fluid tangential force techniques Technol temperature tissues Tribol Tribology vacuum vibration viscoelastic viscosity water film thickness water molecules