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Optimizing the Thermomechanics of Shape-Memory Polymers for Biomedical Applications

Published online by Cambridge University Press:  01 February 2011

Christopher M. Yakacki ,
Ken Gall ,
Robin Shandas ,
Alicia M. Ortega ,
Nick Willett  and
Alan R. Greenberg
Christopher M. Yakacki
Affiliation:
Department of Mechanical Engineering, University of Colorado at Boulder, 80309
Ken Gall
Affiliation:
Department of Mechanical Engineering, University of Colorado at Boulder, 80309
Robin Shandas
Affiliation:
Department of Mechanical Engineering, University of Colorado at Boulder, 80309 Division of Cardiology, The Children's Hospital, Denver, CO 80218
Alicia M. Ortega
Affiliation:
Department of Mechanical Engineering, University of Colorado at Boulder, 80309
Nick Willett
Affiliation:
Department of Mechanical Engineering, University of Colorado at Boulder, 80309
Alan R. Greenberg
Affiliation:
Department of Mechanical Engineering, University of Colorado at Boulder, 80309
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Abstract

We examine the shape-memory effect in polymer networks intended for biomedical applications. The polymers were photopolymerized from tert-butyl acrylate (tBA) with polyethyleneglycol dimethacrylate (PEGDMA) acting as a crosslinker. Three-point flexural tests were used to systematically investigate the thermomechanics of shape-storage deformation and shape recovery. The glass transition temperature (Tg) of the polymers varied over a range of 100°C and is dependent on the molecular weight and concentration of the crosslinker. The polymers show 100% strain recovery up to maximum strains of approximately 80% at low and high deformation temperatures (Td). Free strain recovery was determined to depend on the temperature during deformation; lower deformation temperatures (Td < Tg) decreased the temperature required for free strain recovery. Constrained stress recovery shows a complex evolution as a function of temperature and also depends on Td. The thermomechanical results are discussed in light of potential biomedical applications and a prototype stent that can be activated at body temperature is presented.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 855: Symposium W – Mechanically Active Materials , 2004 , W3.27
Copyright
Copyright © Materials Research Society 2005

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References

REFERENCES

[1] Otsuka, K. and Wayman, C. M., “Shape Memory Materials” New York: Cambridge University Press, 1998.Google Scholar
[2] Ota, S., “Current Status of Irradiated Heat-Shrinkable Tubing in Japan,” Rad. Phys. And Chem., vol. 18, no. 1–2, pp. 81–87, 1981.Google Scholar
[3] El Feninat, F., Laroche, G., Fiset, M., and Mantovani, D., “Shape memory materials for biomedical applications.” Adv. Eng. Mater., vol. 4, no. 3, pp. 91–104, 2002.Google Scholar
[4] Lendlein, A. and Langer, R., “Biodegradable, elastic shape-memory polymers for potential biomedical applications.” Science, vol. 296, pp. 1673–1676, 2002.Google Scholar
[5] Metzger, M. F., Wilson, T. S., Schumann, D., Matthews, D. L., and Maitland, D. J., “Mechanical properties of mechanical actuator for treating ischemic stroke,” Biomed. Microdevices, vol. 4, no. 2, pp. 89–96, 2002.Google Scholar
[6] Maitland, D. J., Metzger, M. F., Schumann, D., Lee, A., Wilson, T. S., “Photothermal properties of shape memory polymer micro-actuators for treating stroke.” Las. Surg. Med., vol. 30, no. 1, pp.1–11, 2002.Google Scholar
[7] Metcalfe, A., Desfaits, A. C., Salazkin, I., Yahia, L., Sokolowski, W. M., Raymond, J., “Cold hibernated elastic memory foams for endovascular interventions,” Biomater., Vol. 24, no. 3, pp. 491–497, 2003.Google Scholar
[8] Ferrera, D. A., “Shape memory polymer intravascular delivery system with heat transfer medium,” US Patent No. 6, 224, 610, 2001.Google Scholar
[9] Lee, A. P., Northrup, M. A., Ciarlo, D. R., Krulevitch, P. A., and Benett, W. J., “Release mechanism utilizing shape memory polymer material,” US Patent No. 6, 102, 933, 2000.Google Scholar
[10] Lee, A. P. and Fitch, J. P., “Micro devices using shape memory polymer patches for mated connections,” US Patent No. 6, 086, 599, 2000.Google Scholar
[11] Gall, K., Dunn, M. L., Liu, Y., Finch, D., Lake, M., and Munshi, N. A., “Shape Memory Polymer Nano Composites” Acta Mater., vol. 50, pp. 5115–5126, 2002.Google Scholar
[12] Gall, K., Kreiner, P., Turner, D., and Hulse, M., “Shape Memory Polymers for MicroElectroMechanical Systems” J. MEMS, vol. 13, pp. 472–483.Google Scholar
[13] Liu, Y., Gall, K., Dunn, M. L., and McCluskey, P., “Thermomechanical Recovery Couplings of Shape Memory Polymers in Flexure.” Smart Materials & Structures, vol. 12, pp. 947–954, 2003.Google Scholar
[14] Bertrand, O. F., Sipehia, R., Mongrain, R., et al. “Biocompatibility aspects of new stent technology.” J Am Coll Cardiol. Vol. 32, pp. 562–71, 1998.Google Scholar
[15] Cribier, A., Eltchaninoff, H., Bash, A., Borenstein, N., Tron, C., Bauer, F., Derumeaux, G., Anselme, F., Laborde, F., Leon, M. B., “Percutaneous transcatheter implantation of an aortic valve prosthesis for calcific aortic stenosis: first human case description”, Circulation, vol. 24, pp. 3006–3008, 2002.Google Scholar