, Volume 6, Issue 1, pp 75–83 | Cite as

Synchronous measurement of tribocharge and force at the footpads of freely moving animals

  • Yi Song
  • Zhouyi Wang
  • Jun Zhou
  • Yang Li
  • Zhendong DaiEmail author
Open Access
Research Article


Hypothesis on electrostatic attraction mechanisms involving the hairy adhesion of climbing animals has been a matter of controversy for several years. The detection of tribocharge and forces at attachment organs of animals is a practical method of clarifying the dispute with respect to electrostatic attraction in the attachment of animals. Nonetheless, the tribo-electrification is rarely examined in the contact-adhesion of animals (especially in their free and autonomous attachment) due to the lack of available devices. Therefore, the present study involves establishing a method and an apparatus that enables synchronous detection of tribocharge and contact forces to study tribo-electrification in the free locomotion of geckos. A type of a combined sensor unit that consists of a three-dimensional force transducer and a capacitor-based charge probe is used to measure contact forces and tribocharge with a magnitude corresponding to several nano-Coulombs at a footpad of geckos when they climb vertically upward on an acrylic oligomer substrate. The experimental results indicate that tribocharge at the footpads of geckos is related to contact forces and contact areas. The measured charge allows the expectation of an exact attraction with magnitude corresponding to dozens of newtons per square meter and provides a probability of examining tribo-electrification in animal attachment from a macro level.


tribocharge forces synchronous measurement animal free locomotion 



The authors extend their sincere appreciation to Wenbo Wang for raising geckos and aiding in performing the 3D microscopy and to the reviewers for their constructive advices. This study was supported by grants from the National Natural Science Foundation of China (Grants No. 51435008) and funding from the Jiangsu Innovation Program for Graduate Education (Grants No. KYLX16_0328). All applicable institutional and/or national guidelines for the care and use of animals were followed in the study.


  1. [1]
    Persson B N J. On the mechanism of adhesion in biological systems. J Chem Phys 118(16): 7614–7621 (2003)CrossRefGoogle Scholar
  2. [2]
    Gorb S N, Varenberg M, Peressadko A, Tuma J. Biomimetic mushroom-shaped fibrillar adhesive microstructure. J R Soc Interface 4(13): 271–275 (2007)CrossRefGoogle Scholar
  3. [3]
    Qu L T, Dai L M, Stone M, Xia Z H, Wang Z L. Carbon nanotube arrays with strong shear binding-on and easy normal lifting-off. Science 322(5899): 238–242 (2008)CrossRefGoogle Scholar
  4. [4]
    Wang Z Y, Song Y, Dai Z D. Use of opposite frictional forces by animals to increase their attachment reliability during movement. Friction 1(2): 143–149 (2013)CrossRefGoogle Scholar
  5. [5]
    Zhou M, Pesika N, Zeng H B, Tian Y. Recent advances in gecko adhesion and friction mechanisms and development of gecko-inspired dry adhesive surfaces. Friction 1(2): 114–129 (2013)CrossRefGoogle Scholar
  6. [6]
    Autumn K, Sitti M, Liang Y A, Peattie A M, Hansen W R, Sponberg S, Kenny T W, Fearing R, Israelachvili J N, Full R J. Evidence for van der Waals adhesion in gecko setae. Proc Natl Acad Sci USA 99(19): 12252–12256 (2002)CrossRefGoogle Scholar
  7. [7]
    Autumn K, Liang Y A, Hsieh S T, Zesch W, Chan W P, Kenny T W, Fearing R, Full R J. Adhesive force of a singlegecko foot-hair. Nature 405(6787): 681–685 (2000)CrossRefGoogle Scholar
  8. [8]
    Stork N E. Experimental analysis of adhesion of Chrysolina polita (Chrysomelidae: Coleoptera) on a variety of surfaces. J Exp Biol 88(1): 91–107 (1980)Google Scholar
  9. [9]
    Huber G, Mantz H, Spolenak R, Mecke K, Jacobs K, Gorb S N, Arzt E. Evidence for capillarity contributions to gecko adhesion from single spatula nanomechanical measurements. Proc Natl Acad Sci USA 102(45): 16293–16296 (2005)CrossRefGoogle Scholar
  10. [10]
    Prevenslik T. Electrostatic Gecko Mechanism. Tribol Ind 31(1–2): 61–66 (2009)Google Scholar
  11. [11]
    Izadi H, Penlidis A. Polymeric bio-inspired dry adhesives: van der Waals or electrostatic interactions? Macromol React Eng 7(11): 588–608 (2013)CrossRefGoogle Scholar
  12. [12]
    Harper W R. Contact and Frictional Electrification. Morgan Hill (USA): Laplacian Press, 1998.Google Scholar
  13. [13]
    Lowell J, Rose-Innes A C. Contact electrification. Adv Phys 29(6): 947–1023 (1980)CrossRefGoogle Scholar
  14. [14]
    Izadi H, Stewart K M E, Penlidis A. Role of contact electrification and electrostatic interactions in gecko adhesion. J R Soc Interface 11(98): 20140371 (2014)CrossRefGoogle Scholar
  15. [15]
    Full R J, Tu M S. Mechanics of six-legged runners. J Exp Biol 148(1): 129–146 (1990)Google Scholar
  16. [16]
    Dai Z D, Wang Z Y, Ji A H. Dynamics of gecko locomotion: a force-measuring array to measure 3D reaction forces. J Exp Biol 214(5): 703–708 (2011)CrossRefGoogle Scholar
  17. [17]
    Reedyk C W, Perlman M M. The measurement of surface charge. J Electrochem Soc 115(1): 49–51 (1968)CrossRefGoogle Scholar
  18. [18]
    Bassen H I, Smith G S. Electric field probes—A review. Ieee Tranc Antenn Propag 31(5): 710–718 (1983)CrossRefGoogle Scholar
  19. [19]
    Greason W D. Investigation of a test methodology for triboelectrification. J Electrostat 49(3–4): 245–256 (2000)CrossRefGoogle Scholar
  20. [20]
    Seyam A M F, Cai Y Y, Oxenham W. Devices for measuring electrostatic generation and dissipation on the surfaces of polymeric materials. J Text Instit 100(4): 338–349 (2009)CrossRefGoogle Scholar
  21. [21]
    Zhang Y Y, Shao T M. A method of charge measurement for contact electrification. J Electrostat 71(4): 712–716 (2013)CrossRefGoogle Scholar
  22. [22]
    Chiou Y C, Chang Y P, Lee R T. Tribo-electrification mechanism for self-mated metals in dry severe wear process: Part I. pure hard metals. Wear 254(7–8): 606–615 (2003)CrossRefGoogle Scholar
  23. [23]
    Budakian R, Putterman S J. Correlation between charge transfer and stick-slip friction at a metal-insulator interface. Phys Rev Lett 85(5): 1000–1003 (2000)CrossRefGoogle Scholar
  24. [24]
    Gady B, Reifenberger R, Rimai D S, DeMejo L P. Contact electrification and the interaction force between a micrometer-size polystyrene sphere and a graphite surface. Langmuir 13(9): 2533–2537 (1997)CrossRefGoogle Scholar
  25. [25]
    Liu S H, Wei G H, Liu Z C. Electrostatic Theory and Electrostatic Protection. Beijing (China): Weapons Industry Press, 1999.Google Scholar
  26. [26]
    Wu Q, Ji A H, Wang Z Y, Dai Z D. Improvement and test for a force sensor's natural frequency. Chin. J. Sens. Actuat. 23(2): 235–238 (2010)Google Scholar
  27. [27]
    Cheng D K. Field and Wave Electromagnetics. 2nd ed. New York: Addison-Wesley, 1989.Google Scholar
  28. [28]
    ESDEMC Technology. ES111 digital static charge meter. User's Manual (2011)Google Scholar
  29. [29]
    Huber G, Gorb S N, Hosoda N, Spolenak R, Arzt E. Influence of surface roughness on gecko adhesion. Acta Biomater 3(4): 607–610 (2007)CrossRefGoogle Scholar
  30. [30]
    Maladen R D, Ding Y, Li C, Goldman D I. Undulatory swimming in sand: subsurface locomotion of the sandfish lizard. Science 325(5938): 314–318 (2009)CrossRefGoogle Scholar
  31. [31]
    Autumn K, Hsieh S T, Dudek D M, Chen J, Chitaphan C, Full R J. Dynamics of geckos running vertically. J Exp Biol 209(2): 260–272 (2006)CrossRefGoogle Scholar
  32. [32]
    Wang Z Y, Wang J T, Ji A H, Zhang Y Y, Dai Z D. Behavior and dynamics of gecko's locomotion: The effects of moving directions on a vertical surface. Chin Sci Bull 56(6): 573–583 (2011)CrossRefGoogle Scholar
  33. [33]
    Lacks D J, Sankaran R M. Contact electrification of insulating materials. J Phys D Appl Phys 44(45): 453001 (2011)CrossRefGoogle Scholar
  34. [34]
    Alibardi L. Cell biology of adhesive setae in gecko lizards. Zoology 112(6): 403–424 (2009)CrossRefGoogle Scholar
  35. [35]
    Apodaca M M, Wesson P J, Bishop K J M, Ratner M A, Grzybowski B A. Contact electrification between identical materials. Angew Chem 122(5): 958–961 (2010)CrossRefGoogle Scholar
  36. [36]
    Lowell J, Truscott W S. Triboelectrification of identical insulators. II. Theory and further experiments. J Phys D Appl Phys 19(7): 1281–1298 (1986)CrossRefGoogle Scholar
  37. [37]
    Eason E V, Hawkes E W, Windheim M, Christensen D L, Libby T, Cutkosky M R. Stress distribution and contact area measurements of a gecko toe using a high-resolution tactile sensor. Bioinspir Biomim 10(1): 16013 (2015)CrossRefGoogle Scholar
  38. [38]
    Wang S H, Lin L, Xie Y N, Jing Q S, Niu S M, Wang Z L. Sliding-triboelectric nanogenerators based on in-plane chargeseparation mechanism. Nano Lett 13(5): 2226–2233 (2013)CrossRefGoogle Scholar

Copyright information

© The author(s) 2017

Open Access: The articles published in this journal are distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors and Affiliations

  • Yi Song
    • 1
    • 2
  • Zhouyi Wang
    • 1
    • 3
  • Jun Zhou
    • 3
  • Yang Li
    • 3
  • Zhendong Dai
    • 1
    • 3
    Email author
  1. 1.Institute of Bio-inspired Structure and Surface EngineeringNanjing University of Aeronautics and AstronauticsNanjingChina
  2. 2.College of Mechanical and Electrical EngineeringNanjing University of Aeronautics and AstronauticsNanjingChina
  3. 3.College of AstronauticsNanjing University of Aeronautics and AstronauticsNanjingChina

Personalised recommendations