Pressure is one of the significant physical parameters strongly associated to life and production.¹ There are numerous methods for measuring pressure. Among them, pressure sensors are significant sensing devices that facilitate advancements in a variety of disciplines and advance society’s intelligence. However, the majority of pressure sensors currently explored rely on capacitive, piezoelectric, and piezoresistive systems, which are vulnerable to electromagnetic interference. In addition, for multipoint pressure measurement, these sensors require an array design, resulting in a complex fabrication procedure. In addition, the array design increases the number of wires, which might lead to unequal current distribution and certain safety hazards in practical implementations.² Fiber Bragg grating (FBG) pressure sensors, on the other hand, employ gratings as sensing elements and may engrave many gratings on a single optical fiber, making multipoint distributed pressure measurements easier.^3,4 In addition, the FBG pressure sensor’s strong antielectromagnetic interference capability and great safety are a result of its usage of optical signals for sensing. It is appropriate for pressure monitoring in areas with severe electromagnetic interference or dangerous conditions, such as the aircraft,^5,6 oil wells,^{7 – 9} and pipelines.^{10 – 14} In addition, FBG pressure sensors have been implemented in biological domains, such as blood pressure monitoring,^{15 – 17} sleep quality monitoring,¹⁸ and plantar pressure monitoring,^{19 – 23} among others. It has significant consequences for medical diagnostics and rehabilitation^{5,24 – 28} and also advances the prevention of diabetic lesions and prosthetic development.^29,30 Research on FBG pressure sensors has increased in recent years, as shown in Fig. 1, since research on pressure sensors has received a great deal of attention, but there is still a big research opportunity for it.

Electric heating garment can improve the thermal comfort for people living and working in cold environment. Compared with passive heating materials, electrical heating shows dominant advantages on reusability, controlled temperature, safety and so on. This review article systematically introduced the material preparation, electric-thermal properties, advantages and disadvantages of the existing flexible heating elements, and elaborated the research and application progress of smart garments in detail, providing reference for the research of flexible heating elements and smart garments. And the existing challenges and the possible future perspectives were also discussed.

A facile method for preparing an easy processing, repeatable and flexible pressure sensor was presented via the synthesis of modified multi-walled carbon nanotubes (m-MWNTs) and polyurethane (PU) films. The surface modification of multi-walled carbon nanotubes (MWNTs) simultaneously used a silane coupling agent (KH550) and sodium dodecyl benzene sulfonate (SDBS) to improve the dispersibility and compatibility of the MWNTs in a polymer matrix. The electrical property and piezoresistive behavior of the m-MWNT/PU composites were compared with raw multi-walled carbon nanotube (raw MWNT)/PU composites. Under linear uniaxial pressure, the m-MWNT/PU composite exhibited 4.282%kPa⁻¹ sensitivity within the pressure of 1 kPa. The nonlinear error, hysteresis error and repeatability error of the piezoresistivity of m-MWNT/PU decreased 9%, 16.72% and 54.95% relative to raw MWNT/PU respectively. Therefore, the piezoresistive response of m-MWNT/PU had better stability than that of raw MWNT/PU composites. The m-MWNT/PU sensors could be utilized in wearable devices for body movement detection, monitoring of respiration and pressure detection in garments.