This paper presents simulation models developed for investigating singlemode-multimode-singlemode (SMS) structures, with the intention of utilising precise nano-scale 3D printing to print the center-section of the structures modelled. The models allow the design of structures for use in SMS fiber sensors, replacing the silica fiber center-section structures commonly used, with 3D printed elements. The paper discusses the process of evaluating and validating COMSOL propagation models by comparison to existing reported results and proposes the use of SMS self-imaging length and the transmission spectra as useful metrics for model comparisons. Both 2D and 3D COMSOL models are developed, and both show good agreement in calculating self-imaging length with the other referenced models. In particular, the 3D model not only simulates the self-imaging length with high accuracy, but also shows good spectral agreement with the referenced models and an analytical calculation. In addition, results from previously published work by the group are used for comparison with the 3D COMSOL model. • 3D nano-printing can potentially fabricate complex optical fiber sensor structures • Investigating the use of COMSOL Multiphysics to model fiber sensor structures • Singlemode-multimode-singlemode structures modelled in 2D and 3D using COMSOL • Self-imaging length and spectra used as comparison metrics between different models • 3D COMSOL model shows good agreement with other models and analytic results

This paper presents a Systematic Literature Review (SLR) on clothing pressure (CP) measuring systems, emphasising studies related to underwear. CP is a key element contributing to fit comfort and has drawn attention from researchers in fit optimization of close-fit garments. As key contributions, the study explores four essential aspects: a typology for CP measurement techniques, the evolution of CP measurement, the challenges associated with measuring CP, and the criteria for choosing a CP measurement mechanism (i.e. clothing pressure sensors for a specific smart textile application. The authors further discuss the opportunities for improvements in existing CP measuring mechanisms, highlighting future avenues in the study area. Furthermore, to the best of the authors' knowledge, the study is unique in terms of systematically reviewing the theme of CP measuring of undergarments. This SLR disseminates comprehensive knowledge on CP, which is beneficial for academics to stimulate further scholarly research in future and industrialists to implement more objective and cost-effective approaches in enhancing the fit comfort of underwear. Knowledge contribution from this review is expected to promote the health of garment consumers through increasing the availability of comfort-fit underwear.