1,721,134 research outputs found
A wearable sensor for monitoring neurotransmitters in sweat for therapeutic and diagnostic analyses
No full textA novel Bioelectronic pH sensor with enhanced sensitivity based on an Organic Electrochemical Transistor
No full textIndumento di sicurezza, metodo per realizzare tale indumento e sistema di sicurezza e controllo
No full textLa presente invenzione riguarda un indumento realizzato in tessuto, indossabile da un utente, in cui detto indumento comprende un dispositivo transponder, avente una antenna di ricetrasmissione ed una unità di prossimità, collegata a detta antenna, e configurata per rilevare un segnale di prossimità emesso da un dispositivo emettitore, ricevuto mediante detta antenna e trasmettere un segnale di distanziamento per comunicare la distanza da detto dispositivo emettitore. I circuiti elettronici che costituiscono detta antenna e detta unità di prossimità sono integrati nel tessuto di detto indumento.
La presente invenzione riguarda anche un metodo per l’integrazione del circuito di un dispositivo transponder ed un sistema di sicurezza e controllo
Charge Carrier Mobility in Organic Mixed Ionic–Electronic Conductors by the Electrolyte-Gated van der Pauw Method
Full text linkOrganic mixed ionic–electronic conductors (OMIECs) combine electronic semiconductor functionality with ionic conductivity, biocompatibility, and electrochemical stability in water and are currently investigated as the active material in devices for bioelectronics, neuromorphic computing, as well as energy conversion and storage. Operation speed of such devices depends on fast electronic transport in OMIECs. However, due to contact resistance problems, reliable measurements of electronic mobility are difficult to achieve in this class of materials. To address the problem, the electrolyte-gated van der Pauw (EgVDP) method is introduced for the simple and accurate determination of the electrical characteristics of OMIEC thin films, independent of contact effects. The technique is applied to the most widespread OMIEC blend, poly(3,4-ethylenedioxythiophene) doped with poly(styrenesulfonic acid) (PEDOT:PSS). By comparing with organic electrochemical transistor (OECT) measurements, it is found that gate voltage dependent contact resistance effects lead to systematic errors in OECT based transport characterization. These observations confirm that a contact-independent technique is crucial for the proper characterization of OMIECs, and the EgVDP method reveals to be a simple, elegant, but effective technique for this scope
ORGANIC SEMICONDUCTING CRYSTALS AS ROOM TEMPERATURE RADIATION DETECTORSAstroparticle, Particle, Space Physics and Detectors for Physics Applications
No full textWe report on the use of organic semiconducting single crystals (OSSCs) as direct ionizing radiation detectors that directly convert the X-ray photons into an electrical signal, thanks to their stability, good transport properties and large interaction volume. X-ray detectors, based on low-cost solution-grown OSSCs are here shown to operate at room temperature, providing a stable linear response with increasing dose rate in atmosphere and in radiation-hard environment. The intrinsic conversion of ionizing radiation within the crystals allowed one to fabricate all-organic optically transparent devices, indicating OSSCs as very promising candidates for a novel generation of low-cost, room temperature radiation detector
Surface and Defect States in Semiconductors Investigated by Surface PhotovoltageDefects in Semiconductors
No full textThe aim of this chapter is a throughout description and discussion of surface photovoltage spectroscopy. The basic physical principles, experimental details, and relevant results of the method are described, and the capability of the method to extract material properties like optical band gap and defect-related states is discussed. The method presents several advantages, as it allows for the identification of conduction versus valence band nature of the defect-related transitions and the defect level positions within the band gap. Moreover, it allows for the detection of relatively low densities of surface defects as well as their cross-sections. The application of the method to different materials and structures is discussed, ranging from bulk semiconductors to low-dimensional systems, to nanostructures
Fully Textile X-Ray Detectors Based on Fabric-Embedded Perovskite Crystals
Full text linkThe interest and thrust for wearable ionizing radiation dosimeters are rapidly growing, stimulated by a large number of different applications impacting on humankind, spanning from medicine to civil security and space missions. Lead halide perovskites are considered one of the most promising classes of novel materials for X-ray detectors due to their superior electronic and detection performance coupled with compatibility with solution-based printing processes, allowing fabrication onto flexible substrates. It is reported on fully textile perovskite-based direct X-ray detectors, where the photoactive layer is constituted by a silk-satin fabric functionalized with methylammonium lead bromide perovskite crystals embedded in the textile. The reliability of the proposed fabrication process, based on simple and low-tech deposition techniques adaptable to industrial printing technologies for textiles, is assessed by realizing different detector's architectures that exhibit comparable detection performances. Sensitivity values up to (12.2 +/- 0.6) mu C Gy(-1) cm(-2) and a limit of detection down to 3 mu Gy s(-1) are achieved, and low bias operation (down to 1 V) is demonstrated, validating wearable applications. Further, fully textile pixelated matrix X-ray sensors are implemented and tested, providing the proof of principle for large-area scalability
Oxygen Gas Sensing Using a Hydrogel-Based Organic Electrochemical Transistor for Work Safety Applications
Full text linkOxygen depletion in confined spaces represents one of the most serious and underestimated dangers for workers. Despite the existence of several commercially available and widely used gas oxygen sensors, injuries and deaths from reduced oxygen levels are still more common than for other hazardous gases. Here, we present hydrogel-based organic electrochemical transistors (OECTs) made with the conducting polymer poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT:PSS) as wearable and real-time oxygen gas sensors. After comparing OECT performances using liquid and hydrogel electrolytes, we identified the best PEDOT:PSS active layer and hydrogel coating (30 μm) combination for sensing oxygen in the concentration range of 13–21% (v/v), critical for work safety applications. The fast O2 solubilization in the hydrogel allowed for gaseous oxygen transduction in an electrical signal thanks to the electrocatalytic activity of PEDOT:PSS, while OECT architecture amplified the response (gain ̴ 104). OECTs proved to have comparable sensitivities if fabricated on glass and thin plastic substrates, (−12.2 ± 0.6) and (−15.4 ± 0.4) μA/dec, respectively, with low power consumption (<40 μW). Sample bending does not influence the device response, demonstrating that our real-time conformable and lightweight sensor could be implemented as a wearable, noninvasive safety tool for operators working in potentially hazardous confined spaces
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