Project description:Sparse seismic instrumentation in the oceans limits our understanding of deep Earth dynamics and submarine earthquakes. Distributed acoustic sensing (DAS), an emerging technology that converts optical fiber to seismic sensors, allows us to leverage pre-existing submarine telecommunication cables for seismic monitoring. Here we report observations of microseism, local surface gravity waves, and a teleseismic earthquake along a 4192-sensor ocean-bottom DAS array offshore Belgium. We observe in-situ how opposing groups of ocean surface gravity waves generate double-frequency seismic Scholte waves, as described by the Longuet-Higgins theory of microseism generation. We also extract P- and S-wave phases from the 2018-08-19 [Formula: see text] Fiji deep earthquake in the 0.01-1 Hz frequency band, though waveform fidelity is low at high frequencies. These results suggest significant potential of DAS in next-generation submarine seismic networks.
Project description:Rayleigh scattering enhanced nanoparticle-doped optical fibers, for distributed sensing applications, is a new technology that offers unique advantages to optical fiber community. However, the existing fabrication technology, based on in situ grown alkaline earth nanoparticles, is restricted to few compositions and exhibit a great dependence on many experimental conditions. Moreover, there is still several uncertainties about the effect of drawing process on the nanoparticle characteristics and its influence on the scattering enhancement and the induced optical loss. In this work, we shed light on all these issues that prevent the progress in the field and demonstrate the suitability of doping optical fibers with YPO4 nanocrystals for developing tunable Rayleigh scattering enhanced nanoparticle-doped optical fibers. An exhaustive 3D microstructural study reveals that their features are closely linked to the fiber drawing process, which allow the size and shape engineering at the nanoscale. In particular, the YPO4 nanocrystals preserve their features to a large extent when the optical fibers are drawn below 1950 °C, which allows obtaining homogeneous nanocrystal features and optical performance. Fabricated fibers exhibit a tunable enhanced backscattering in the range of 15.3-54.3 dB, with respect to a SMF-28 fiber, and two-way optical losses in the range 0.3-160.7 dB/m, revealed by Optical Backscatter Reflectometry (OBR) measurements. This allows sensing lengths from 0.3 m up to more than 58 m. The present work suggests a bright future of YPO4 nanocrystals for distributed sensing field and open a new gate towards the incorporation of other rare-earth orthophosphate (REPO4) nanocrystals with pre-defined characteristics that will overcome the limitations of the current in situ grown alkaline earth-based technology.
Project description:Wearable electronics used in smart clothing for healthcare monitoring or personalized identification is a new and fast-growing research topic. The challenge is that the electronics has to be simultaneously highly stretchable, mechanically robust and water-washable, which is unreachable for traditional electronics or previously reported stretchable electronics. Herein we report the wearable electronics of sliver nanowire (Ag-NW)/poly(dimethylsiloxane) (PDMS) nanocomposite which can meet the above multiple requirements. The electronics of Ag-NW/PDMS nanocomposite films is successfully fabricated by an original pre-straining and post-embedding (PSPE) process. The composite film shows a very high conductivity of 1.52 × 10(4) S cm(-1) and an excellent electrical stability with a small resistance fluctuation under a large stretching strain. Meanwhile, it shows a robust adhesion between the Ag-NWs and the PDMS substrate and can be directly machine-washed. These advantages make it a competitive candidate as wearable electronics for smart clothing applications.
Project description:In response to global aging, there have been improvements in healthcare, exercise therapy, health promotion, and other areas. There is a gradually increasing demand for such equipment for health purposes. The main purpose of smart clothing is to monitor the physical health status of the user and analyze the changes in physiological signals of the heart. Therefore, this study aimed to examine the factors that affect the measurement of the heart's physiological parameters and the users' comfort while wearing smart clothing as well as to validate the data obtained from smart clothing. This study examined the subjective feelings of users (aged 20-60 years) regarding smart clothing comfort (within 12 h); the median values were comfortable and above (3.4-4.5). The clothing was combined with elastic conductive fiber and spandex to decrease the relative movement of the fiber that acts as a sensor and increase the user's comfort. Future studies should focus on the optimization of the data obtained using smart clothing. In addition to its use in medical care and post-reconstructive surgery, smart clothing can be used for home care of older adults and infants.
Project description:With the advancement of artificial intelligence (AI) and the Internet of Things (IoT), smart clothing, which has enormous growth potential, has developed to suit consumers' individualized demands in various areas. This paper aims to construct a model that integrates that technology acceptance model (TAM) and functionality-expressiveness-aesthetics (FEA) model to explore the key factors influencing consumers' smart clothing purchase intentions (PIs). Partial least squares structural equation modeling (PLS-SEM) was employed to analyze the data, complemented by fuzzy-set qualitative comparative analysis (fsQCA). The PLS-SEM results identified that the characteristics of functionality (FUN), expressiveness (EXP), and aesthetics (AES) positively and significantly affect perceived ease of use (PEOU), and only EXP affects perceived usefulness (PU). PU and PEOU positively impact consumers' attitudes (ATTs). Subsequently, PU and consumers' ATTs positively influence PIs. fsQCA revealed the nonlinear and complex interaction effects of the factors influencing consumers' smart clothing purchase behaviors and uncovered five necessary and six sufficient conditions for consumers' PIs. This paper furthers theoretical understanding by integrating the FEA model into the TAM. Additionally, on a practical level, it provides significant insights into consumers' intentions to purchase smart clothing. These findings serve as valuable tools for corporations and designers in strategizing the design and promotion of smart clothing. The results validate theoretical conceptions about smart clothing PIs and provide useful insights and marketing suggestions for smart clothing implementation and development. Moreover, this study is the first to explain smart clothing PIs using symmetric (PLS-SEM) and asymmetric (fsQCA) methods.
Project description:There has been increased interest to develop protective fabrics and clothing for protecting the wearer from hazards such as chemical, biological, heat, UV, pollutants etc. Protective fabrics have been conventionally developed using a wide variety of techniques. However, these conventional protective fabrics lack breathability. For example, conventional protective fabrics offer good protection against water but have limited ability in removing the water vapor and moisture. Fibers and membranes fabricated using electrospinning have demonstrated tremendous potential to develop protective fabrics and clothing. These fabrics based on electrospun fibers and membranes have the potential to provide thermal comfort to the wearer and protect the wearer from wide variety of environmental hazards. This review highlights the emerging applications of electrospinning for developing such breathable and protective fabrics.
Project description:The marriage of textiles with artificial muscles to create smart textiles is attracting great attention from the scientific community and industry. Smart textiles offer many benefits including adaptive comfort and high conformity to objects while providing active actuation for desired motion and force. This paper introduces a new class of programmable smart textiles created from different methods of knitting, weaving, and sticking fluid-driven artificial muscle fibers. Mathematical models are developed to describe the elongation-force relationship of the knitting and weaving textile sheets, followed by experiments to validate the model effectiveness. The new smart textiles are highly flexible, conformable, and mechanically programmable, enabling multimodal motions and shape-shifting abilities for use in broader applications. Different prototypes of the smart textiles are created with experimental validations including various shape-changing instances such as elongation (up to 65%), area expansion (108%), radial expansion (25%), and bending motion. The concept of reconfiguring passive conventional fabrics into active structures for bio-inspired shape-morphing structures is also explored. The proposed smart textiles are expected to contribute to the progression of smart wearable devices, haptic systems, bio-inspired soft robotics, and wearable electronics.
Project description:Thermal ablation is achieved by delivering heat directly to tissue through a minimally invasive applicator. The therapy requires a temperature control between 50-100 °C since the mortality of the tumor is directly connected with the thermal dosimetry. Existing temperature monitoring techniques have limitations such as single-point monitoring, require costly equipment, and expose patients to X-ray radiation. Therefore, it is important to explore an alternative sensing solution, which can accurately monitor temperature over the whole ablated region. The work aims to propose a distributed fiber optic sensor as a potential candidate for this application due to the small size, high resolution, bio-compatibility, and temperature sensitivity of the optical fibers. The working principle is based on spatial multiplexing of optical fibers to achieve 3D temperature monitoring. The multiplexing is achieved by high-scattering, nanoparticle-doped fibers as sensing fibers, which are spatially separated by lower-scattering level of single-mode fibers. The setup, consisting of twelve sensing fibers, monitors tissue of 16 mm × 16 mm × 25 mm in size exposed to a gold nanoparticle-mediated microwave ablation. The results provide real-time 3D thermal maps of the whole ablated region with a high resolution. The setup allows for identification of the asymmetry in the temperature distribution over the tissue and adjustment of the applicator to follow the allowed temperature limits.
Project description:Restricted by the hierarchical and centralized system architecture, smart buildings face challenges such as limited adaptability and robustness, single application functionalities, and complex configurations. To address the above shortcomings, we learn from the activity patterns of natural bee swarms and propose Honeycomb, an open-source smart-building solution with fully distributed architecture. Honeycomb is a robust, flexible smart-building solution without any central server or global leader. An asynchronous leaderless spanning tree-based communication pattern is developed to generate and maintain the communication topology of Honeycomb in real time. Benefiting from this communication pattern, Honeycomb has plug-and-play ability. Various distributed applications are designed for building operating tasks and are deployed in a real Honeycomb prototype. The prototype demonstrates significant energy efficiency improvement from the control of the heating, ventilation, and air conditioning (HVAC) system with video-based occupancy information. Feedback on our Honeycomb prototype through questionnaires of users shows high acceptance of the controlled indoor environment.