The aim is to analyze the bra design features and fit problems of older women and to design solutions to improve bra fit and design for older women. Twenty-six participants aged 62 ± 4 years participated in bra fitting experiments with eight commercial senior bras featuring different design features. The bra design features were firstly quantified into 19 parameters including dimensions and/or curvatures, material properties, bra tension and elongation. The associations between bra design features and related problems were then systematically addressed. The most common fit problem was bulging, which was affected by underarm height (r = 0.23, p < 0.01), underband elongation (r = –0.25, p < 0.01), rigidity of wing fabric (r = 0.30, p < 0.01), rigidity of top of the elastic underband (r = 0.32, p < 0.01), rigidity of bottom elastic band (r = 0.32, p < 0.01), and tension of the underband (r = 0.23, p < 0.01). Except for neckline length, other measurements were also found to be related with bra fit problems. The well-fitting bras for older women have wide straps, large width at the front of strap, sufficient vertical cup length, increased gore height and underarm height, fabric straps on the back, and an underband with high rigidity. The reasons are discussed, and new design solutions are given. The design recommendations formulated in this study can advance the design and development processes of bras for older women.

In the intimate apparel industry, the evaluation of bra designs has traditionally relied on the practical experience of designers. The limitations of conventional evaluation methods have rendered difficulties in analysing the effect of bra design features. This research study therefore proposes a novel method to simulate the interaction of the bra strap and the movement of upper body. The influence of the different design features of bra straps is evaluated through a full factorial analysis with the finite element model. It is found that elongation has the most significant influence while Young’s modulus has the least influence on the displacement of the bra strap during movement. The proposed method is proven to be an effective and scientific approach to enhance the bra design and eliminate the time-consuming ‘trial and error’ testing in the design process and hence, provide effective design modifications for today’s ever-changing lingerie market.

The conductivity and sensing stability of yarn-based strain sensors are still challenges when it comes to practical applications. To address these challenges, surface engineering of polyurethane (PU) yarn was introduced to improve its surface hydrophilicity for better deposition of MXene nanosheets in its dispersion. The introduction of Ag nanoparticles via magnetron sputtering greatly improved the surface conductivity; meanwhile, the encapsulation of the PDMS protective layer effectively enhanced the sensing stability over 15,000 cycling process, as well as the working range with a gauge factor value over 700 under a strain range of 150–300%. Moreover, the exploration of its applications in human motion monitoring indicate that the prepared strain-sensing yarn shows great potential in detecting both tiny motions or large-scale movements of the human body, which will be suitable for further development into multifunctional smart wearable sensors or metaverse applications in the future.