Asymmetric spatula heads combined with lateral forces provide a mechanism for controlling the adhesive attachment of a range of spider species

References

• Autumn K, Liang YA, Hsieh ST, Zesch W, Chan WP, Kenny TW, Fearing R, Full RJ. Adhesive force of a single gecko foot-hair. Nature. 2000;405(6787):681–85.
   PubMed Web of Science ®Google Scholar
• Autumn K, Sitti M, Liang YCA, Peattie AM, Hansen WR, Sponberg S, Kenny TW, Fearing R, Israelachvili JN, Full RJ. Evidence for van der waals adhesion in gecko setae. Proceedings of the National Academy of Sciences of the United States of America. 2002;99(19):12252–12256.
   PubMed Web of Science ®Google Scholar
• Autumn K, Gravish N. Gecko adhesion: evolutionary nanotechnology. Philosophical Transactions of the Royal Society a-Mathematical Physical and Engineering Sciences. 2008;366(1870):1575–1590.
   PubMedGoogle Scholar
• Bhushan B. Adhesion of multi-level hierarchical attachment systems in gecko feet. Journal of Adhesion Science and Technology. 2007;21(12–13):1213–1258.
   Web of Science ®Google Scholar
• Russell AP, Johnson MK, Delannoy SM. Insights from studies of gecko-inspired adhesion and their impact on our understanding of the evolution of the gekkotan adhesive system. Journal of Adhesion Science and Technology. 2007;21(12–13):1119–1143.
   Web of Science ®Google Scholar
• Yao H, Gao H. Mechanical principles of robust and releasable adhesion of gecko. Journal of Adhesion Science and Technology. 2007;21(12–13):1185–1212.
   Web of Science ®Google Scholar
• Niederegger S, Gorb SN. Friction and adhesion in the tarsal and metatarsal scopulae of spiders. Journal of Comparative Physiology a-Neuroethology Sensory Neural and Behavioral Physiology. 2006;192(11):1223–1232.
   PubMedGoogle Scholar
• Kesel AB, Martin A, Seidl T. Getting a grip on spider attachment: an AFM approach to microstructure adhesion in arthropods. Smart Materials & Structures. 2004;13(3):512–518.
   Web of Science ®Google Scholar
• Lin AYM, Brunner R, Chen PY, Talke FE, Meyers MA. Underwater adhesion of abalone: the role of van der Waals and capillary forces. Acta Materialia. 2009;57(14):4178–4185.
   Web of Science ®Google Scholar
• Autumn K, Peattie AM. Mechanisms of adhesion in geckos. Integrative and Comparative Biology. 2002;42:1081–1090.
   PubMed Web of Science ®Google Scholar
• Federle W. Why are so many adhesive pads hairy? Journal of Experimental Biology. 2006;209(14):2611–2621.
   PubMedGoogle Scholar
• Peattie AM. Functional demands of dynamic biological adhesion: an integrative approach. Journal of Comparative Physiology B-Biochemical Systemic and Environmental Physiology. 2009;179(3):231–239.
   Google Scholar
• Pesika NS, Zeng HB, Kristiansen K, Zhao BX, Tian Y, Autumn K, Israelachvili J. Gecko adhesion pad: a smart surface? Journal of Physics-Condensed Matter. 2009;21 464132.
   Google Scholar
• Kim TW, Bhushan B. Adhesion analysis of multi-level hierarchical attachment system contacting with a rough surface. Journal of Adhesion Science and Technology. 2007;21(1):1–20.
   Web of Science ®Google Scholar
• Peattie AM, Full RJ. Phylogenetic analysis of the scaling of wet and dry biological fibrillar adhesives. Proceedings of the National Academy of Sciences USA. 2007;104(47):18595–18600.
   PubMedGoogle Scholar
• Autumn K, Hsieh ST, Dudek DM, Chen J, Chitaphan C, Full RJ. Dynamics of geckos running vertically. Journal of Experimental Biology. 2006;209(2):260–272.
   PubMedGoogle Scholar
• Xing M, Zhong W, Xu XL, Thomson D. Adhesion force studies of nanofibers and nanoparticles. Langmuir. 2010;26(14):11809–11814.
   PubMed Web of Science ®Google Scholar
• Gao HJ, Wang X, Yao HM, Gorb S, Arzt E. Mechanics of hierarchical adhesion structures of geckos. Mechanics of Materials. 2005;37(37):275–285.
   Google Scholar
• Arzt E, Gorb S, Spolenak R. From micro to nano contacts in biological attachment devices. Proceedings of the National Academy of Sciences USA. 2003;100(19):10603–10606.
   PubMed Web of Science ®Google Scholar
• Tian Y, Pesika N, Zeng HB, Rosenberg K, Zhao BX, McGuiggan P, Autumn K, Israelachvili J. Adhesion and friction in gecko toe attachment and detachment. Proceedings of the National Academy of Sciences USA. 2006;103(51):19320–19325.
   PubMed Web of Science ®Google Scholar
• Autumn K, Dittmore A, Santos D, Spenko M, Cutkosky M. Frictional adhesion: a new angle on gecko attachment. Journal of Experimental Biology. 2006;209(18):3569–3579.
   PubMedGoogle Scholar
• Zhao BX, Pesika N, Rosenberg K, Tian Y, Zeng HB, McGuiggan P, Autumn K, Israelachvili J. Adhesion and friction force coupling of gecko setal arrays: implications for structured adhesive surfaces. Langmuir. 2008;24(4):1517–1524.
   PubMedGoogle Scholar
• Zeng HB, Pesika N, Tian Y, Zhao BX, Chen YF, Tirrell M, Turner KL, Israelachvili JN. Frictional adhesion of patterned surfaces and implications for gecko and biomimetic systems. Langmuir. 2009;25(13):7486–7495.
   PubMedGoogle Scholar
• Israelachvili J. Intermolecular and surface forces. 2nd ed. Waltham, MA: Academic Press; 1991.
   Google Scholar
• Leckband D, Israelachvili J. Intermolecular forces in biology. Quarterly Reviews of Biophysics. 2001;34(2):105–267.
   PubMed Web of Science ®Google Scholar
• Huber G, Mantz H, Spolenak R, Mecke K, Jacobs K, Gorb SN, Arzt E. Evidence for capillarity contributions to gecko adhesion from single spatula nanomechanical measurements. Proceedings of the National Academy of Sciences USA. 2005;102(45):16293–16296.
   PubMed Web of Science ®Google Scholar
• Puthoff JB, Prowse MS, Wilkinson M, Autumn K. Changes in materials properties explain the effects of humidity on gecko adhesion. Journal of Experimental Biology. 2010;213(21):3699–3704.
   PubMedGoogle Scholar
• Johnson KL, Kendall K, Roberts AD. Surface energy and contact of elastic solids. Proceedings of the Royal Society London Series a-Mathematical and Physical Sciences. 1971;324(1558):301.
   Web of Science ®Google Scholar
• Boesel LF, Greiner C, Arzt E, del Campo A. Gecko-inspired surfaces: a path to strong and reversible dry adhesives. Advanced Materials. 2010;22(19):2125–2137.
   PubMed Web of Science ®Google Scholar
• Coddington JA, Levi HW. Systematics and evolution of spiders (Araneae). Annual Review of Ecology, Evolution, and Systematics. 1991;22:565–592.
   Google Scholar
• Roberts M. Spiders of Britain and Northern Europe collins field guide. New York, NY: Harper Collins; 1995.
   Google Scholar
• Vollrath F, Selden P. The role of behavior in the evolution of spiders, silks, and webs. Annual Review of Ecology Evolution and Systematics. 2007;38:819–846.
   Web of Science ®Google Scholar
• Moon MJ, Park JG. Fine structural analysis on the dry adhesion system of the jumping spider Plexippus setipes (Araneae: Salticidae). Animal Cells and Systems. 2009;13(2):161–167.
   Web of Science ®Google Scholar
• Rizzo NW, Gardner KH, Walls DJ, Keiper-Hrynko NM, Ganzke TS, Hallahan DL. Characterization of the structure and composition of gecko adhesive setae. Journal of the Royal Society Interface. 2006;3(8):441–451.
   PubMed Web of Science ®Google Scholar
• Keane PN. Temporary adhesive systems in invertebrates: comparing and contrasting morphological, nanomechanical, and biomolecular characteristics. [dissertation]: University College Dublin; 2012.
   Google Scholar
• Schultz S, Schultz M. The tarantula keeper's guide. 2nd ed. New York, NY: Barron's Educational Series; 1998.
   Google Scholar
• Cambridge FOP. Arachnida - araneida and opiliones, biologia centrali-americana. Zoology. 1897;2:1–40.
   Google Scholar
• Ausserer A. Zweiter Beitrag zur Kenntniss der Arachniden-Familie der Territelariae Thorell (Mygalidae Autor). Verh. zool.-bot. Ges. Wien. 1875;25:125–206.
   Google Scholar
• Smith AM. A new species of Haplopelma (Araneae: Theraphosidae), with notes on two close relatives. Mygalomorph. 1996;1:21–32.
   Google Scholar
• Griswold CE, Ramirez MJ, Coddington JA, Platnick NI. Atlas of phylogenetic data for entelegyne spiders (Araneae: Araneomorphae: Entelegynae) with comments on their phylogeny. Proceedings of the California Academy of Sciences. 2005;56(Suppl. 2):1–317, 319–324.
   Google Scholar
• Clerck C. Svenska spindlar, uti sina hufvud-slågter indelte samt under några och sextio särskildte arter beskrefne och med illuminerade figurer uplyste. Stockholmiae. 1757.
   Google Scholar
• Kuo J. Electron microscopy: methods and protocols, Methods in Molecular Biology, 2nd ed. New York, NY: Humana Press; 2007.
   Google Scholar
• Hutter JL, Bechhoefer J. Calibration of atomic force microscope tips. Review of Scientific Instruments. 1993;64(7):1868–1873.
   Web of Science ®Google Scholar
• Wavemetrics Inc. IGOR Pro 6.10A. Lake Oswego, OR; 1988–2009.
   Google Scholar
• SPSS Inc. TwoStep cluster analysis. Technical report. Chicago, IL; 2004.
   Google Scholar
• Rasband, WS. ImageJ [Internet], U. S. national institutes of health, Bethesda, Maryland, 1997–2012. Available from http://www.imagej.nih.gov/ij/
   Google Scholar
• Abramoff, Magelhaes PJ, Ram SJ. Image processing with image. Biophotonics International. 2004;11(7):36–42.
   Google Scholar
• Huber G, Gorb SN, Spolenak R, Arzt E. Resolving the nanoscale adhesion of individual gecko spatulae by atomic force microscopy. Biology Letters. 2005;1(1):2–4.
   PubMed Web of Science ®Google Scholar
• Kesel AB, Martin A, Seidl T. Adhesion measurements on the attachment devices of the jumping spider evarcha arcuata. Journal of Experimental Biology. 2003;206(16):2733–2738.
   PubMedGoogle Scholar
• Fabritius H, Sachs C, Raabe D, Nikolov S, Friak M, Neugebauer J. Chitin: formation and diagenesis. In: Gupta NS, editor. New York, NY: Springer; 2011. p. 35–60.
   Google Scholar
• Varenberg M, Pugno NM, Gorb SN. Spatulate structures in biological fibrillar adhesion. Soft Matter. 2010;6(14):3269–3272.
   Google Scholar
• Gao HJ, Yao HM. Shape insensitive optimal adhesion of nanoscale fibrillar structures. Proceedings of the National Academy of Sciences USA. 2004;101(21):7851–7856.
   PubMed Web of Science ®Google Scholar