1,720,966 research outputs found
Wearable and Stretchable Strain Sensors: Materials, Sensing Mechanisms, and Applications
Get PDFRecent advances in the design and implementation of wearable resistive, capacitive, and optical strain sensors are summarized herein. Wearable and stretchable strain sensors have received extensive research interest due to their applications in personalized healthcare, human motion detection, human–machine interfaces, soft robotics, and beyond. The disconnection of overlapped nanomaterials, reversible opening/closing of microcracks in sensing films, and alteration of the tunneling resistance have been successfully adopted to develop high-performance resistive-type sensors. On the other hand, the sensing behavior of capacitive-type and optical strain sensors is largely governed by their geometrical changes under stretching/releasing cycles. The sensor design parameters, including stretchability, sensitivity, linearity, hysteresis, and dynamic durability, are comprehensively discussed. Finally, the promising applications of wearable strain sensors are highlighted in detail. Although considerable progress has been made so far, wearable strain sensors are still in their prototype stage, and several challenges in the manufacturing of integrated and multifunctional strain sensors should be yet tackled
Experimental characterization of a dielectric elastomer fluid pump and optimizing performance via composite materials
No full text Dielectric elastomer is a class of soft actuators with exceptionally high strain capabilities and energy density. It is being studied for wide range of various applications and has been hypothesized to be a good material for biomedical blood pumps. We performed experimental characterization of a simple dielectric elastomer fluid pump to test this feasibility. We achieved substantial flow rates (10 mL/s) and actuation pressure (45 mm Hg) and found that dielectric elastomer fluid pump performance can exhibit significant resonance effects, with drastic reduction in performance at non-resonance frequencies. The elastomer, VHB™, a soft acrylic polymer, is frequently used to fabricate dielectric elastomer due to high deformation abilities and dielectric constant but has a well-known shortcoming of high viscoelasticity, which severely limited the dielectric elastomer pumps’ performance except at very low frequencies. In this study, we demonstrated that the introduction of a thin elastic and non-viscous layer to the VHB, such as latex, to form a composite dielectric elastomer could address this limitation. The composite dielectric elastomer pump has an increased resonance frequency, significantly improved performances at frequencies of 0.75–2 Hz, and higher maximum achievable actuation volume, flow rate, actuation pressures, and power output. Remaining challenges of realizing a dielectric elastomer blood pump are discussed. </jats:p
Functional Soft Fibers and Textiles: Multi-Material Approaches for Actuation and Sensing
No full textMeasuring and inducing mechanical deformation are crucial to applications in healthcare, human-machine interfaces, and soft robotics. However, conventional rigid transducers lack the flexibility, integration, and adaptability required in adaptive soft systems. Integrating sensing and actuation within multimaterial fibers and incorporating them into functional textiles offers a promising route to achieve distributed and autonomous functionality. Yet challenges persist in scalability, material processing, and functional integration.
This thesis addresses these challenges by employing multimaterial thermal drawing to embed magnetically, electrically, thermally, and optically responsive materials into fibers designed for adaptive applications, yielding five key innovations:
(i) High-aspect-ratio magnetic fiber actuators and textiles: Soft magnetic fibers embedding neodymium-iron-cobalt-boron (NdFeCoB) microparticles within thermoplastic elastomers exhibit exceptional stretchability and precise magnetic responsiveness. These fibers enable untethered, complex deformation suited to soft robotics, textile-supported prosthetics, and minimally invasive medical applications.
(ii) Conductive nanocomposite fibers for integrated sensing: A novel sensing framework using fibers composed of carbon nanotubes and carbon-loaded polyethylene composites provides real-time motion tracking via piezoresistive feedback. Integrated into textiles, these fibers support interactive rehabilitation systems, adaptive orthotic devices, and closed-loop control in wearable technologies.
(iii) Soft electromagnetic fiber actuators: Beyond passive actuation, fibers embedding liquid metal conductors and miniaturized electromagnets within magnetic composite cores enable enhanced actuation precision, controllable force modulation, and improved mechanical stability. Detailed electromagnetic mechanical analyses guide optimized designs, significantly boosting dynamic soft robotic performance.
(iv) Heat-responsive liquid crystal elastomer (LCE) fiber actuators: Leveraging the intrinsic anisotropy, reversible deformation, high energy density, and multi-stimuli responsiveness of LCEs, thermally responsive fibers are developed. Tailored polymer chemistries, processing conditions, and rheological modifiers facilitate repeatable thermal deformation. Furthermore, dispersing LCE and LCE-glycerol composites within thermoplastic elastomers provides a scalable pathway to high-performance soft fiber actuators.
(v) Stretchable 1D photonic crystal fibers for mechanical sensing: Expanding the scope of soft, stretchable optical fibers fabricated via thermal drawing, novel photonic crystal fibers with sub-100 nm periodic structures are introduced. Combining structural colors with mechanical resilience, these fibers enable real-time mechanical sensing. Their scalable fabrication promotes integration into interactive textiles for embedded optical signal transduction.
Overall, this thesis establishes multimaterial thermal drawing as a versatile platform for creating soft, functional fibers that integrate magnetic, electrical, thermal, and photonic properties. By incorporating NdFeCoB microparticles, conductive nanocomposites, LCEs, electromagnets, and liquid metal conductors, these fibers offer unprecedented proprioceptive feedback, adaptive actuation, and interactivity, paving the way for advanced biomedical devices, intelligent textiles, and next-generation soft robotic systems.FIMA
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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