Post-gel polymerisation shrinkage profiling of polymer biomaterials using a chirped fibre Bragg grating

• Published in: Scientific reports Vol. 11; no. 1; p. 1410
• Main Authors: Rajan, Ginu, Wong, Alex, Farrar, Paul, Prusty, Gangadhara B.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 14-01-2021; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/54; 639/624/1075/1083; Biomaterials; Composite materials; Curing; Dental restorative materials; Humanities and Social Sciences; Measurement techniques; multidisciplinary; Polymerization; Polymers; Science; Science (multidisciplinary); Spatial distribution; Temperature gradients; Temperature requirements
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-80838-5

A strain profile measurement technique using a chirped fibre Bragg grating (CFBG) sensor by implementing an integration of differences (IOD) method is reported in this paper. Using the IOD method the spatial distribution of strain along the length of the CFBG is extracted from its power reflectance spectra. As a proof of concept demonstration, the developed technique is applied to measure the polymerisation shrinkage strain profile of a photo-cured polymer dental composite which exhibits a non-uniform strain distribution attributed to the curing lamp characteristics. The result from the CFBG technique is compared with that of an FBG array embedded in the dental composite and is correlated with the degree of conversion of the material which also depends on the curing lamp intensity distribution. This technology will have significant impact and applications in a range of medical, materials and engineering areas where strain or temperature gradient profile measurement is required in smaller scales.