1,720,980 research outputs found
Electrical Characterization of PEDOT:PSS Strips Deposited by Inkjet Printing on Plastic Foil for Sensor Manufacturing
No full textInkjet printing is a viable method for rapid and low-cost manufacturing of flexible sensors. In this paper, we study a technique for inkjet printing of poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT: PSS) strips. A low-cost inkjet desktop printer is used for the fabrication of PEDOT: PSS resistive strips on polyimide substrates. Accounting for several geometries of printed PEDOT: PSS strips, we assess the variability of the fabrication process. Owing to the printing process, we can easily choose the width, length, and thickness. We found that printed strips on polyimide foils show a conductivity equal to 115 S/cm, which linearly increases with the strip thickness. The maximum variability is lower than 13%. The frequency analysis shows a purely resistive impedance in the frequency range investigated (100 Hz-100 kHz). Moreover, the strips folded up to 1000 times shows a resistance variation lower than 6%. The study demonstrates that inkjet printing is a viable method for the simple, fast, reliable, and low-cost fabrication of PEDOT:PSS-based sensors on plastic substrates and circuit interconnections
Ion buffering and interface charge enable high performance electronics with organic electrochemical transistors
No full textOrganic electrochemical transistors rely on ionic-electronic volumetric interaction to provide a seamless interface between biology and electronics with outstanding signal amplification. Despite their huge potential, further progress is limited owing to the lack of understanding of the device fundamentals. Here, we investigate organic electrochemical transistors in a wide range of experimental conditions by combining electrical analyses and device modeling. We show that the measurements can be quantitatively explained by nanoscale ionic-electronic charge interaction, giving rise to ion buffering and interface charge compensation. The investigation systematically explains and unifies a wide range of experiments, providing the rationale for the development of high-performance electronics. Unipolar inverters - universal building blocks for electronics - with gain larger than 100 are demonstrated. This is the highest gain ever reported, enabling the design of devices and circuits with enhanced performance and opening opportunities for the next-generation integrated bioelectronics and neuromorphic computing
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Physical Modeling of Amorphous InGaZnO Thin-Film Transistors: The Role of Degenerate Conduction
No full textIn amorphous indium-gallium-zinc oxide thin-film transistors (a-IGZO TFTs), the electron mobility easily exceeds 102/Vs and degenerate band conduction is observed. On the other hand, the field-effect mobility is gate voltage-dependent. Here, we propose a physical model for a-IGZO TFTs accounting for both the non-degenerate and degenerate conductions of trapped and free charges. The comparison between the model and the measurements shows that: 1) the shape of the drain current is almost completely defined by the localized density of states and 2) a transition from non-degenerate-to-degenerate conductions is always observed. This explains the measured gate voltage-dependent field-effect mobility and provides a simple and unified physical picture of the charge transport in a-IGZO TFTs
ON-OFF current ratio in Organic Ferroelectric Memory Diodes: The role of the Density of States
No full textSolution processed Organic Ferroelectric Memory Diodes (OFMDs) are one of the most promising non-volatile memory elements for large area flexible electronics [1]-[4]. In OFMDs it is possible to improve the ON/OFF current ratio by orders of magnitude by simply increasing the charge injection barrier [5], [6], at the expenses of the data retention [7]. In this work we demonstrate that it is possible to tune the ON/OFF current ratio by orders of magnitude even in the case of very low charge injection barriers, paving the way for long-missing OFMDs
Organic electrochemical transistor immuno-sensor operating at the femto-molar limit of detection
No full textThe interfacing of biomaterials to electronic devices is one of the most challenging research fields that has relevance to both fundamental studies and the development of highly performing biosensors. Organic Electrochemical transistors, using an aqueous electrolyte solution, offer a unique set of advantages in the development of biosensor devices. In this paper, we report highly selective organic electrochemical transistor based immune-sensor by modifying the gate electrode with polyclonal anti-human Immunoglobulin G (anti-IgG) antibodies. Extremely low detection of Immunoglobulin G (IgG) at the femto-molar detection limit has been achieved
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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