Dual Ageing Mechanisms in UHMWPE Heart Valve Discs Revealed by Terahertz Time-Domain Spectroscopy
DOI:
https://doi.org/10.65795/5g0wqr08Keywords:
Terahertz time-domain spectroscopy (THz-TDS), Ultra-high molecular weight polyethylene (UHMWPE), Mechanical heart valve materials, Polymer ageing and fatigue, Non-destructive evaluationAbstract
UHMWPE heart valve discs undergo surface and bulk microstructural change during cyclic service, yet no single non-contact, non-ionizing, non-destructive method can simultaneously resolve both. This study asked whether THz-TDS could detect and distinguish these concurrent ageing processes in UHMWPE discs from the TTK Chitra heart valve TC2. Measurements were taken at six locations per disc across the 0.2–0.6 THz range, before and after 400 million cycles of accelerated durability testing. After testing, the refractive index fell by 2.38%, the extinction coefficient by 11.46%, and the absorption coefficient by 15.56% - against expectation, all three optical losses decreased rather than increased. Spatial variability roughly halved across all parameters, with the extinction coefficient CV dropping from 32.75% to 17.32% and the absorption coefficient CV from 37.00% to 19.13%. THz-TDS resolves two concurrent ageing mechanisms - surface polishing and bulk microstructural reorganisation - within a single non-contact measurement, establishing its value as an NDE tool for polymer prosthetic valve assessment.
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References
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Data Availability Statement
The data that supports the findings of this study are available from the corresponding authors upon reasonable request, as the data is part of a translational project.
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Copyright (c) 2026 Subhash N.N., Muraleedharan C. V. , Krishnan Balasubramaniam (Author)
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How to Cite
Accepted 27-05-2026
Published 09-07-2026
