Wearable tensile strain sensors have attracted substantial research interest due to their great potential in applications for the real-time detection of human motion and health through the construction of body-sensing networks. Conventional devices, however, are constantly demonstrated in non-real world scenarios, where changes in body temperature and humidity are ignored, which results in questionable sensing accuracy and reliability in practical applications. In this work, a fabric-like strain sensor is developed by fabricating graphene-modified Calotropis gigantea yarn and elastic yarn (i.e. Spandex) into an independently crossed structure, enabling the sensor with tunable sensitivity by directly altering the sensor width. The sensor possesses excellent breathability, allowing water vapor generated by body skin to be discharged into the environment (the water evaporation rate is approximately 2.03 kg m−2 h−1) and creating a pleasing microenvironment between the sensor and the skin by avoiding the hindering of perspiration release. More importantly, the sensor is shown to have a sensing stability towards changes in temperature and humidity, implementing sensing reliability against complex and changeable wearable microclimate. By wearing the sensor at various locations of the human body, a full-range body area sensing network for monitoring various body movements and vital signs, such as speaking, coughing, breathing and walking, is successfully demonstrated. It provides a new route for achieving wearing-comfortable, high-performance and sensing-reliable strain sensors.
Tag: fibers
Edaphic and climatic factors affecting phenology of naturally growing calotropis procera in semi-arid regions of Kenya
Background and Objective: Cultivating Calotropis procera for fiber supply to the textile industry can improve the livelihoods of communities in arid and semi-arid regions. This study determined edaphic and climatic factors affecting phenological traits of C. procera in the semi-arid regions of Kenya. Materials and Methods: Repeated measure research design was used with multistage sampling technique to monitor activity indices, number of flowers and fruits and phenophase intensities. Climatic and edaphic factors of study sites were also monitored. Data was analyzed using linear, Poisson log linear regression based on Generalized Estimation Equation (GEE) and Mixed Analysis of Variance (ANOVA). Results: High Soil Organic Carbon (OC) content (3%) and exchangeable Na (112.5 ppm) at (0-20) cm soil depth were recorded in Tharaka. High mean monthly rainfall (160.37 mm) was recorded in Makueni. Flowering activity indices in (June-August, 2018) were 64.97% and 69.6% in Tharaka and Makueni, respectively . Available P, average monthly rainfall and temperature had significant association with flowering and fruiting activity indices (p<0.05). The mean number of flowers and fruits per stem were significantly associated with soil available P, exchangeable Na and OC content (p<0.05). Though edaphic factors were not significantly associated with phenophase intensities of C. procera, average monthly rainfall and temperature were positively and negatively associated with phenophase intensities, respectively . Conclusion: Available P, exchangeable Na, available K and OC content noticeably affect phenological traits of naturally growing C. procera. Rains and temperatures are critical climatic factors affecting phenological traits of C. procera.
Research mapping of Indonesia nano-lignocellulose fiber studies and its potential for industrial application
Nano-lignocellulose fibers (NLCFs) studies have been undertaken intensively in Indonesia because of its extraordinary properties of the nanofibers for various applications. The Government of Indonesia has also supported the development of the studies into industrial application. However, the studies about the nanofibers were still limited thereby creating barriers to the implementation of the studies into industrial application. Based on this study, NLCFs comprised lignocellulose nanofibers, bacterial nanocellulose, nanocrystalline cellulose, and nanofibrillated cellulose. From this study, empty fruit bunch of oil palm became the most studied natural fiber for NLCFs isolation, followed with other sources, such as bacteria, cassava, bamboo, and pineapple. From the Google Earth and ArcGis mapping, NLCFs studies were mostly conducted in Java Island over other Indonesia islands. The phenomenon was due to the availability of nanofibers-producing machines and its instrumentations. There has been yet no specific regulation supporting the development of NLCF studies, but there are some ministerial roadmaps and plans created to support the studies. Yet, NLCF studies have been not only concerned on its isolation and characterization but also the studies have been concentrated for exploring the NLCF potential for industrial application purposes, such as: paper making, pharmaceutics, food and packaging, medicine, and bio-absorbent.