Abstract
The mechanical and viscoelastic properties of the hydrogels are important in determining their suitability for biological applications. An advanced three-dimensional imaging technique has now been developed to examine the mechanical properties of these hydrogels under spherical indentation. A dual-camera spherical indentation system has been set-up and alginate hydrogels 20mm in diameter and between 400µm and 600µm in thickness were examined. A small number of PVC particles (75 –100µm in diameter) were suspended throughout the hydrogels. Each hydrogel was suspended around it outer edge while submerged in water. A stainless steel sphere was placed centrally on the hydrogel surface causing it to deform. A CCD camera connected to a long working distance microscope recorded the deformation displacement. A second camera positioned above the sample holder recorded the resulting displacement of particles. The images from both cameras were analyzed and used to establish the mechanical behavior of the hydrogel. This dual-camera approach allowed the distribution of localized strain at different points in the hydrogel to be examined during deformation. The mechanical properties of the hydrogels can be calculated from the deformation data using inverse finite element modeling based on a large deformation theory. This technique has several advantages over conventional mechanical characterization techniques including nondestructive measurements, hydrogels can be maintained under sterile or cell culture conditions during measurement, repeated measurement can be taken of the same sample at different time points and there is no backing substrate effect during indentation. This approach has many potential applications including determination of the elastic or viscoelastic properties of hydrogels, examination of the strain distribution during deformation and detection of local defects or abnormalities in the materials mechanical properties.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Drury JL, Mooney DJ, (2003) Hydrogels for tissue engineering: scaffold design variables and applications. Biomaterials 24:4337–4351
Qiu Y, Park K, (2001) Environment sensitive hydrogels for drug delivery. Adv Drug Deliver Rev 53:321–339
Ahearne M, Yang Y, El Haj AJ et al (2005) Characterizing the viscoelastic properties of thin hydrogel-based constructs for tissue engineering applications. J R Soc Interface 2:455–463
Orwin EJ, Borene ML, Hubel A, (2003) Biomechanical and optical characteristics of a corneal stromal equivalent. J. Biomech. Eng. 125:439–444.
Ahearne M, Yang Y, Liu KK (2008) Mechanical characterization of hydrogels for tissue engineering applications. In: Ashammakhi N, ed, Topics in Tissue Engineering 4,12:1–16
Ahearne M, Yang Y, Then, KY et al (2008) Non-destructive mechanical characterization of UVA/riboflavin crosslinked collagen hydrogels. Br J Ophthalmol 92:268–271
Ju BF, Liu KK, (2002) Characterizing viscoelastic properties of thin elastomeric membrane. Mech Mater 34:485–491
Yang WH, Hsu KH, (1971) Indentation of a circular membrane. J Appl Mech 38:227–230
Hsu FPK, Liu AMC, Downs J et al (1995) A triplane video based experimental system for studying axisymmetrically inflated biomembranes. IEEE Trans Biomed Eng 42:442–449
Downs J, Halperin HR, Humphrey JD et al (1990) An improved video-based computer tracking system for soft biomaterials testing. IEEE Trans Biomed Eng 37:903–907
Everett WN, Shih P, Humphrey JD, (2005) A bi-plane video based system for studying the mechanics of arterial bifurcations. Exp Mech 45:377–382
Ling P, Taber LA, Humphrey JD, (2002) Approach to quantify the mechanical behavior of the intact embryonic chick heart. Annals Biomed Eng 30:636–645.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2009 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Ahearne, M., Liu, K.K., Yang, Y. (2009). Dual-Camera Spherical Indentation System for Examining the Mechanical Characteristics of Hydrogels. In: Vander Sloten, J., Verdonck, P., Nyssen, M., Haueisen, J. (eds) 4th European Conference of the International Federation for Medical and Biological Engineering. IFMBE Proceedings, vol 22. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-89208-3_479
Download citation
DOI: https://doi.org/10.1007/978-3-540-89208-3_479
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-89207-6
Online ISBN: 978-3-540-89208-3
eBook Packages: EngineeringEngineering (R0)