Abstract
Instrumented indentation is a common technique for measuring the elastic properties of bulk materials as well as thin films on substrates. However, in traditional indentation, it can be difficult to determine the true deformation of a specimen due to the effects of machine compliance and thermal drift. In the present work, a method is developed to track the in-plane and out-of-plane deformation of a specimen during indentation tests using fluorescent microparticles. Bead tracking and quantitative defocusing methods are used to track the in-plane and out-of-plane displacements of the beads, respectively. Here, we describe the calibration of the system and assess the effects of particle size and magnification on the accuracy and resolution of the system. In addition, results from preliminary indentation tests performed on bulk polydimethylsiloxane specimens are reported. An analysis algorithm was developed to extract the elastic properties by measuring the displacements on the surface as a function of applied indentation force. Results are compared to traditional indentation measurements in which load and displacement are only measured at the indenter.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Oliver WC, Pharr GM (1992) An improved technique for determining hardness and elastic-modulus using load and displacement sensing indentation experiments. J Mater Res 7(6):1564–1583
Sneddon IN (1965) The relation between load and penetration in the axisymmetric Boussinesq problem for a punch of arbitrary profile. Int J Eng Sci 3(1):47–57
VanLandingham MR (2003) Review of instrumented indentation. J Res Natl Inst Stand Technol 108(4):249–265
Fischer-Cripps A (2006) Critical review of analysis and interpretation of nanoindentation test data. Surf Coat Technol 200:4153–4165
Wald MJ, Considine JM, Turner KT (2013) Determining the elastic modulus of compliant thin films supported on substrates from flat punch indentation measurements. Exp Mech doi:10.1007/s11340-012-9705-2
Kaufman JD, Klapperich CM (2009) Surface detection errors cause overestimation of the modulus in nanoindentation on soft materials. J Mech Behav Biomed Mater 2:312–317
Nohava J, Randall NX, Conté N (2009) Novel ultra nanoindentation method with extremely low thermal drift: principle and experimentall results. J Mater Res 24(03):873–882
Oyen M (2013) Nanoindentation of biological and biomimetic materials. Exp Tech 37(1):73–87
Maugis D (2000) Contact, adhesion and rupture of elastic solids, 1st edn. Springer, Berlin
Rogers SS, Waigh TA, Zhao X, Lu JR (2007) Precise particle tracking against a complicated background: polynomial fitting with Gaussian weight. Phys Biol 4:220–227
Prasad V, Semwogerere D, Weeks ER (2007) Confocal microscopy of colloids. J Phys: Condens Matter 19:113102
Semwogerere D, Weeks ER (2005) Confocal microscopy. In: Encyclopedia of biomaterials and biomedical engineering. Taylor & Francis, New York, pp 1–10
Wu M, Roberts JW, Buckley M (2005) Three-dimensional fluorescent particle tracking at micron-scale using a single camera. Exp Fluid 38:461–465
Williams SJ, Park C, Wereley ST (2010) Advances and applications on microfluidic velocimetry techniques. Microfluid Nanofluid 8:709–726
Peterson SD, Chuang HS, Wereley ST (2008) Three-dimensional particle tracking using micro-particle image velocimetry hardware. Meas Sci Technol 19:115406
Zhang Z, Menq C-H (2008) Three-dimensional particle tracking with subnanometer resolution using off-focus images. Appl Opt 47:2361
Mahajan VN (1994) Zernike circle polynomials and optical aberrations of systems with circular pupils. Appl Opt 33(34):8121–8124
Wald MJ, Considine JM, Turner KT (2013) Improved instrumented indentation of soft materials through surface deformation measurements. In: Mechanics of biological systems, vol 5. Springer, New York, pp. 141–147
Acknowledgements
We wish to acknowledge financial support from the US Postal Service and US Forest Service, Forest Products Laboratory.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2014 The Society for Experimental Mechanics, Inc.
About this paper
Cite this paper
Wald, M.J., Considine, J.M., Turner, K.T. (2014). Indentation Measurements on Soft Materials Using Optical Surface Deformation Measurements. In: Barthelat, F., Zavattieri, P., Korach, C., Prorok, B., Grande-Allen, K. (eds) Mechanics of Biological Systems and Materials, Volume 4. Conference Proceedings of the Society for Experimental Mechanics Series. Springer, Cham. https://doi.org/10.1007/978-3-319-00777-9_6
Download citation
DOI: https://doi.org/10.1007/978-3-319-00777-9_6
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-00776-2
Online ISBN: 978-3-319-00777-9
eBook Packages: EngineeringEngineering (R0)