Experimental Mechanics

, Volume 55, Issue 2, pp 427–438 | Cite as

Sensitively Photoelastic Biocompatible Gelatin Spheres for Investigation of Locomotion in Granular Media

  • S.A. Mirbagheri
  • E. Ceniceros
  • M. Jabbarzadeh
  • Z. McCormick
  • H.C. FuEmail author


We present a method for measuring forces in granular media experiments using photoelastic gelatin spheres, which is applicable for investigating the forces generated by organisms moving through noncohesive granular materials. We describe how to fabricate gelatin spheres with appropriate characteristics for high-sensitivity photoelastic measurements. We present a calibration methodology to relate photoelastic signal to force applied to the spheres, and evaluate the photoelastic performance of gelatin spheres as a function of gelatin concentration. The spheres can be used across a range of salinities, allowing investigation of freshwater and marine organisms. We show that photoelastic gelatin spheres can detect forces as small as 1 μN, and quantitatively measure forces with up to 60 μN precision. We provide a proof-of-principle experiment in which the forces exerted by an earthworm in a granular environment are measured.


Photoelasticity Force measurement Granular materials Biolocomotion Burrowing 



We thank Abe Clark for information about photoelastic disks. HCF, AM, and MJ were supported by National Science Foundation award CBET-1252182-CAREER to HCF.

Supplementary material

(MPG 8.71 MB)


  1. 1.
    Murphy EAK, Dorgan KM (2011) Burrow extension with a proboscis: mechanics of burrowing by the glycerid Hemipodus simplex. J Exp Biol 214:1017–1027CrossRefGoogle Scholar
  2. 2.
    Che J, Dorgan KM (2010) Its tough to be small: dependence of burrowing kinematics on body size. J Exp Biol 213:1241–1250CrossRefGoogle Scholar
  3. 3.
    Dorgan KM, Arwade S, Jumars P (2007) Burrowing in marine muds by crack propagation: kinematics and forces. J Exp Biol 210:4198–4212CrossRefGoogle Scholar
  4. 4.
    Maladen RD, Ding Y, Li C, Goldman DI (2009) Undulatory swimming in sand: subsurface locomotion of the sandfish lizard. Science 325:314–318CrossRefGoogle Scholar
  5. 5.
    Winter AG, Deits V RLH, Hosoi AE (2012) Localized fluidization burrowing mechanics of Ensis directus. J Exp Biol 215:2072–2080CrossRefGoogle Scholar
  6. 6.
    Dorgan KM, Law CJ, Rouse GW (2013) Meandering worms: mechanics of undulatory burrowing in muds. Proc R Soc B 280(1757):20122, 948CrossRefGoogle Scholar
  7. 7.
    Juarez G, Lu K, Sznitman J, Arratia PE (2010) Motility of small nematodes in wet granular media. EPL Europhys Lett 92:44,002Google Scholar
  8. 8.
    Jung S (2010) Caenorhabditis elegans swimming in a saturated particulate system. Phys Fluids 22:031,903Google Scholar
  9. 9.
    Majmudar TS, Behringer RP (2005) Contact force measurements and stress-induced anisotropy in granular materials. Nature 435:1079–1082CrossRefGoogle Scholar
  10. 10.
    Wendell DM, Luginbuhl K, Guerrero J, Hosoi A (2012) Experimental investigation of plant root growth through granular substrates. Exp Mech 52(7):945–949CrossRefGoogle Scholar
  11. 11.
    Estep J, Dufek J (2012) Substrate effects from force chain dynamics in dense granular flows. J Geophys Res-Earth Surf 117:F01,028Google Scholar
  12. 12.
    Full RJ, Yamauchi A, Jindrich D (1995) Maximum single leg force production: cockroaches righting on photoelastic gelatin. J Exp Biol 198:2441–2452Google Scholar
  13. 13.
    Harris JK (1978) A photoelastic substrate technique for dynamic measurements of forces exerted by moving organisms. J Microsc 114(2):219–228CrossRefGoogle Scholar
  14. 14.
    Herrel A, Choi HF, Dumont E, Schepper ND, Vanhooydonck B, Aerts P, Adriaens D (2011) Burrowing and subsurface locomotion in anguilliform fish: behavioral specializations and mechanical constraints. J Exp Biol 214:1379–1385CrossRefGoogle Scholar
  15. 15.
    Quillin K (2000) Ontogenetic scaling of burrowing forces in the earthworm Lumbricus terrestris. J Exp Biol 203:2757–2770Google Scholar
  16. 16.
    Doll J, Harjee N, Klejwa N, Kwon R, Coulthard S, Petzold B, Goodman M, Pruitt B (2009) SU-8 force sensing pillar arrays for biological measurements. Lab Chip 9:1449–1454CrossRefGoogle Scholar
  17. 17.
    Ghanbari A, Nock V, Wang W, Blaikie R, Chase G, Chen X, Hann CE (2008) Force pattern characterization of C. elegans in motion. In: Proceedings of 15th International Conference on Mechatronics and Machine Vision in Practice, pp 680–685Google Scholar
  18. 18.
    Jessop HT, Harris FC (1960) Photoelasticity, principles and methods. Dover Publications, New YorkGoogle Scholar
  19. 19.
    Quillin K (1999) Kinematic scaling of locomotion by hydrostatic animals: ontogeny of peristaltic crawling by the earthworm Lumbricus terrestris. J Exp Biol 202:661674Google Scholar
  20. 20.
    Shen XN, Sznitman J, Krajacic P, Lamitina T, Arratia PE (2012) Undulatory locomotion of C. elegans on wet surfaces. Biophys J 102:27722781Google Scholar

Copyright information

© Society for Experimental Mechanics 2014

Authors and Affiliations

  • S.A. Mirbagheri
    • 1
  • E. Ceniceros
    • 1
  • M. Jabbarzadeh
    • 1
  • Z. McCormick
    • 2
  • H.C. Fu
    • 1
    Email author
  1. 1.Department of Mechanical EngineeringUniversity of Nevada RenoRenoUSA
  2. 2.Department of PhysicsUniversity of Nevada RenoRenoUSA

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