scholarly journals The Friction Properties of Firebrat Scales

Biomimetics ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 2 ◽  
Author(s):  
Yuji Hirai ◽  
Naoto Okuda ◽  
Naoki Saito ◽  
Takahiro Ogawa ◽  
Ryuichiro Machida ◽  
...  

Friction is an important subject for sustainability due to problems that are associated with energy loss. In recent years, micro- and nanostructured surfaces have attracted much attention to reduce friction; however, suitable structures are still under consideration. Many functional surfaces are present in nature, such as the friction reduction surfaces of snake skins. In this study, we focused on firebrats, Thermobia domestica, which temporary live in narrow spaces, such as piled papers, so their body surface (integument) is frequently in contact with surrounding substrates. We speculate that, in addition to optical, cleaning effects, protection against desiccation and enemies, their body surface may be also adapted to reduce friction. To investigate the functional effects of the firebrat scales, firebrat surfaces were observed using a field-emission scanning electron microscope (FE-SEM) and a colloidal probe atomic force microscope (AFM). Results of surface observations by FE-SEM revealed that adult firebrats are entirely covered with scales, whose surfaces have microgroove structures. Scale groove wavelengths around the firebrat’s head are almost uniform within a scale but they vary between scales. At the level of single scales, AFM friction force measurements revealed that the firebrat scale reduces friction by decreasing the contact area between scales and a colloidal probe. The heterogeneity of the scales’ groove wavelengths suggests that it is difficult to fix the whole body on critical rough surfaces and may result in a “fail-safe” mechanism.

Author(s):  
Yuji Hirai ◽  
Naoto Okuda ◽  
Naoki Saito ◽  
Takahiro Ogawa ◽  
Ryuichiro Machida ◽  
...  

Friction is an important subject for sustainability due to problems associated with energy loss. Recent years, surface micro- and nanostructures have attracted much attention to reduce friction; however, suitable structures are still under consideration. Many functional surfaces are present in nature, such as the friction reduction surfaces of snake skins. In this study, we focused on firebrats, Thermobia domestica, living in narrow spaces such as under bark, so their surface frequently contacts with surrounding surfaces. We speculate that their body surface would be adapted to reduce friction. To investigate the firebrat surface functions, firebrat surfaces were observed by using a field-emission scanning electron microscope (FE-SEM) and a colloidal probe atomic force microscope (AFM), respectively. Results of surface observations by the FE-SEM revealed that firebrats are entirely covered with scales, whose surfaces have micro groove structures. Scale groove periods around the firebrat's head are almost uniform within a scale but vary between scales. AFM friction force measurements revealed that firebrat scale reduces friction by decreasing contact area between scales and a colloidal probe. The heterogeneity of groove periods of the scales suggest that it is difficult to fix the whole body in particular rough surfaces and that lead to be "fail-safe".


2015 ◽  
Vol 17 (25) ◽  
pp. 16553-16559 ◽  
Author(s):  
Valentina Valmacco ◽  
Gregor Trefalt ◽  
Plinio Maroni ◽  
Michal Borkovec

Direct force measurements between silica particles were carried out using the colloidal probe technique, which is based on an atomic force microscope (AFM).


2019 ◽  
Vol 51 (04) ◽  
pp. 240-248
Author(s):  
Lucas Etzel ◽  
Konstantin Christoph Koban ◽  
Zhouxiao Li ◽  
Konstantin Frank ◽  
Riccardo Enzo Giunta ◽  
...  

Zusammenfassung Hintergrund Dreidimensionale (3D) Oberflächenaufnahmen haben sich als objektiver Mehrwert in der Planung und Dokumentation unterschiedlicher plastisch chirurgischer Eingriffe erwiesen. Obwohl Oberflächen- und Volumenanalysen für einzelne Bereiche wie der Brust und des Gesichts im klinischen Alltag eingesetzt werden, war es bislang nicht ausreichend möglich, Auswirkungen auf die gesamte Körperoberfläche zu erfassen und zu quantifizieren. Ziel dieser Studie war die Implementierung von 360° Ganzkörperscans zur zukünftigen Therapie-Evaluierung beim Lipödem. Patienten, Material und Methoden Drei unterschiedliche 3D Oberflächenscanner (Eva, Thor und Sense) wurden am Probanden hinsichtlich ihrer Reproduzierbarkeit und Präzision für 360° Aufnahmen evaluiert. Unter einem standardisierten Setting bestehend aus einem automatischen Drehteller und definierten Posen wurden axiale Umfangsmessungen und schichtweise Volumina bestimmt. Statistische und klinische relevante Abweichungen wurden untersucht. Ergebnisse Ein standardisierter 360° Scan Ablauf wurde implementiert. Die Reproduzierbarkeit aller Scanner war zufriedenstellend (p > 0,05). Es zeigten sich vergleichbare axiale Umfangsmessungen und Volumina für den Eva und Thor Scanner (p > 0,05). Der Sense Scanner erreichte eine ausreichende Messgenauigkeit im Thoraxbereich, jedoch signifikante Abweichungen an der unteren Extremität (p < 0,05). Die Datenauswertung konnte auf ausgewählte klinische Beispiele übertragen werden. Schlussfolgerung Es konnte erfolgreich eine 360° Oberflächenaufnahmetechnik und Analyse in der Plastischen Chirurgie eingeführt werden. Zwei der getesteten Geräte ermöglichen objektive Umfangs- und Volumenmessungen am gesamten Körper. Das dritte Gerät, der günstige Sense Scanner, ermöglichte zwar 360° Aufnahmen, jedoch war dessen Präzision nicht für alle Bereiche ausreichend. In Zukunft könnten somit die Auswirkungen unterschiedlicher Therapien an der gesamten Körperoberfläche evaluiert werden.


Cell Research ◽  
2003 ◽  
Vol 13 (3) ◽  
pp. 147-158 ◽  
Author(s):  
Masatake KAI ◽  
Chikara KAITO ◽  
Hiroshi FUKAMACHI ◽  
Takayasu HIGO ◽  
Eiji TA-KAYAMA ◽  
...  

2010 ◽  
Vol 1 ◽  
pp. 163-171 ◽  
Author(s):  
W Merlijn van Spengen ◽  
Viviane Turq ◽  
Joost W M Frenken

We have replaced the periodic Prandtl–Tomlinson model with an atomic-scale friction model with a random roughness term describing the surface roughness of micro-electromechanical systems (MEMS) devices with sliding surfaces. This new model is shown to exhibit the same features as previously reported experimental MEMS friction loop data. The correlation function of the surface roughness is shown to play a critical role in the modelling. It is experimentally obtained by probing the sidewall surfaces of a MEMS device flipped upright in on-chip hinges with an AFM (atomic force microscope). The addition of a modulation term to the model allows us to also simulate the effect of vibration-induced friction reduction (normal-force modulation), as a function of both vibration amplitude and frequency. The results obtained agree very well with measurement data reported previously.


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