A Rapid Method to Noninvasively Measure the Viscoelastic Properties of Synthetic Polymers Using Mechanical Vibrations and Photonics

Abstract

Noninvasive measurement of the viscoelastic properties of both natural and synthetic polymers is important for the analysis of implant design and performance as well as in industrial material development. In this study, we used vibrational optical coherence tomography (VOCT) to compare the elastic and viscoelastic properties of silicone polymers with standard tensile stress–strain measurements. VOCT uses acoustic vibrations and infrared light to measure the resonant frequency of viscoelastic materials. The elastic modulus was calculated from the in-phase deformation of the material at fixed frequencies using an empirical calibration curve. Viscous loss was measured after pulsing the samples based on the ratio of mechanovibrational peak widths to heights. The results showed that the optimal cure time and modulus values obtained using VOCT were like those obtained using conventional tensile testing. VOCT could capture results that were comparable to conventional testing while not destroying the material, suggesting its usefulness for in vivo and in situ measurements as well as for early quality control environments during end-use application and fabrication experiments. We conclude that VOCT is a new technique that is comparable to conventional testing for noninvasively and nondestructively measuring the viscoelastic properties of polymers.

Keywords

• silicone
• viscoelasticity
• elastic modulus
• viscous loss
• tensile testing
• infrared light