Recent Advances in Fibrous Materials for Hydroelectricity Generation

Depleting fossil energy sources and conventional polluting power generation pose a threat to sustainable development.Hydroelectricity generation from ubiquitous and spontaneous phase transitions between liquid and gaseous water has been considered a promising strategy for mitigating the energy crisis.Fibrous materials with unique flexibility,processability,multifunctionality,and practicability have been widely applied for fibrous materials-based hydroelectricity generation(FHG).In this review,the power generation mechanisms,design principles,and electricity enhancement factors of FHG are first introduced.Then,the fabrication strategies and characteristics of varied constructions including 1D fiber,1D yarn,2D fabric,2D membrane,3D fibrous framework,and 3D fibrous gel are demonstrated.Afterward,the advanced functions of FHG during water harvesting,proton dissociation,ion separation,and charge accumulation processes are analyzed in detail.Moreover,the potential applications including power supply,energy storage,electrical sensor,and information expression are also discussed.Finally,some existing challenges are considered and prospects for future development are sincerely proposed.

用于高风险环境安全监测和可调热管理的具有分层核壳结构的耐化学品纱线

Chemical resistant textiles are vital for safeguarding humans against chemical hazards in various settings.such as industrialproduction,chemicalaccidents,laboratory activities,and road transportation.However,the ideal integration of chemical resistance,thermal and moisture management,and wearer condition monitoring in conventional chemically protective textiles remains challenging.Herein,the design,manufacturing,and use of stretchable hierarchical core-shell yarns(HCSYs)for integrated chemical resistance,moisture regulation,and smart sensing textiles are demonstrated.These yarns con-tain helically elastic spandex,wrapped silver-plated nylon,and surface-structuredpolytetrafluo-roethylene(PTFE)yarns and are designed and manufactured based on a scalable fabrication process.In addition to their ideal chemical resistance performance,HCSYs can function as multifunctional stretch-able electronics for real-time human motion monitoring and as the basic element of intelligent textiles.Furthermore,a desirable dynamic thermoregulation function is achieved by exploiting the fabric structure with stretching modulation.Our HCSYs may provide prospective opportunities for the future development of smart protective textiles with high durability,flexibility,and scalability.

Study on the influence of pneumatic probe on the wake flow field of transonic turbine cascade

The pneumatic probe is widely used for contact measurements in turbomachinery flow field research.However,it inevitably interferes with the original flow field,leading to additional errors,particularly in wake flow fields or transonic regions with significant pressure gradients.This study employed Reynolds-Averaged Navier-Stokes delete and high-fidelity numerical simulation to investigate the impact of an inserted pneumatic probe on the wake flow field of a transonic turbine blade and compared it to the baseline flow field.Results indicate that the probe causes the shock waves premature occurrence in the high subsonic wake region near the turbine blade trailing edge.These shock waves affect vortex shedding by thickening the boundary layer near the trailing edge and changing the shedding pattern from high-frequency-low-energy to low-frequencyhigh-energy.In addition,the extra flow loss is incurred,and the blade's heat transfer characteristic is changed.This research provides a reference for testing experiments in complex transonic flow fields,guiding experimental researchers to minimize instrument interference with the original flow field.

Hierarchical Structured Fabrics with Enhanced Pressure Sensing Performance Based on Orientated Growth of Functional Bacterial Cellulose

Wearable electronics based on natural biomaterials,such as bacterial cellulose(BC),have shown promise for a variety of healthcare and human-computer interaction applications.However,current BC-based pressure sensors have an inherent limi-tation,which is the two-dimensional rigid structures and limited compressibility of BC restrict the sensitivity and working range for pressure sensing.Here,we propose a strategy for fabricating BC/polypyrrole/spacer fabric(BPSF)pressure sensors with a hierarchical structure constructed by integrating conductive BC nanonetwork into a compressible fabric frame via the in situ biofermentation process.The hierarchical structure design includes a cross-scale network from the nanoscale BC sensor networks to the macroscopic three-dimensional compressible fabric sensor network,which significantly improves the working range(0-300 kPa)and sensitivity(40.62 kPa-1)of BPSF.Via this unique structural design,the sensor also achieves a high fatigue life(~5000 cycles),wearability,and reproducibility even after several washing and abrasion cycles.Furthermore,a flexible and wearable electronic textile featuring an n×n sensing matrix was developed by constructing BPSF arrays,allowing for the precise control of machines and weight distribution analysis.These empirical insights are valuable for the biofabrication and textile structure design of wearable devices toward the realization of highly intuitive human-machine interfaces.