On the use of FBG sensors for measurement of curing strains in photocurable resins

Purpose The objective of this study is to investigate the use of a fibre Bragg grating (FBG) sensor for measuring of curing strains that develop during the solidification of a photocurable resin used in 3D microfabrication. Design/methodology/approach The followed approach consists of embedding a 1,300 nm FBG into a cylindrical specimen, fabricated into a transparent mould, being exposed to ultraviolet laser light. The further development of the cure induced strains under thermal treatment was also studied by post‐conditioning the cylindrical specimen in an oven at 70°C. Findings The experimental results demonstrate the capability of the FBG sensor to provide useful information on the strain build‐up during laser solidification and their post‐cure evolution under the presence of a thermal environment. Research limitations/implications Future work should involve the use of smaller diameter FBG sensors in microstereolithography built parts. Practical implications It is shown that considerable cure strains are developed at the end of the photo‐polymerisation process that eventually can affect the structural resolution of final parts fabricated by microstereolithography. Originality/value The presented method can be used to investigate other photopolymers used in micro‐stereolithography.