Suchergebnisse

Sensing smart labels are an essential component of the Internet of Things (IoT) to provide identification and data. However, the widespread use of these labels into functional devices requires easy integration and power supply. Herein, a smart label is presented with integrated humidity sensor and printed battery. The smart label is composed by detection, communication, control, and energy subsystems. It is based on a screen printed RLC circuit and a printed humidity sensor with electrical linear response. The printed battery based on lithium iron phosphate as an active cathode material is fabricated with six single cells connected in series, leading to approximate to 100 mAh g(-1). The printed humidity sensor has a linear response with a sensitivity of 0.004/% relative humidity (RH). Thus, it demonstrates the development of fully printed smart labels, improving integration into a variety of applications. ; The authors thank the Fundacao para a Ciencia e Tecnologia (FCT) for financial support under the framework of Strategic Funding grants UID/FIS/04650/2020, UID/EEA/04436/2020, and UID/QUI/0686/2020 and project no. PTDC/FIS-MAC/28157/2017. The authors also thank the FCT for financial support under grants SFRH/BD/131729/2017 (N.P.) and SFRH/BPD/112547/2015 (C.M.C.). Financial support from the Basque Government under the ELKARTEK, HAZITEK, and PIBA (PIBA-2018-06) programs was also ...

Printed sensors find an increasing interest essentially due to their characteristics of flexibility and low cost per unit area. In this work a screen printed Wheatstone bridge is presented, suitable for strain sensing applications. A piezoresistive ink composite based on biocompatible thermoplastic elastomer styrene-ethylene/butylene-styrene (SEBS) as matrix and multi-walled carbon nanotubes (MWCNT) as nanofillers was used as a piezoresistive sensing material. Different deposition techniques, such as, screen printing, spray painting and drop casting were evaluated in order to optimize the resistance variation related to the piezoresistive effect. Several Wheatstone bridges with one and two sensors were designed to obtain an output sensitivity as a function of the strain submitted to the sensors. Further, different sensor geometries were evaluated to maximize the strain output sensitivity. Electro-mechanical bending tests showed a good linearity and a sensitivity up to 18 mV/V in the all screen printed half Wheatstone bridge output with two MWCNT/SEBS sensors. ; This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013 and project PTDC/EEI-SII/5582/2014. V. Correia and P. Costa thank the FCT for the SFRH/BPD/97739/2013 and SFRH/BPD/110914/2015 grants respectively. The authors acknowledge funding by the Spanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2016-76039-C4-3-R. SLM thank financial support from the Basque Government Industry Department under the ELKARTEK and HAZITEK programs. ...

Organic photodetectors (PDs) based on printing technologies will allow to expand the current field of PD applications toward large-area and flexible applications in areas such as medical imaging, security, and quality control, among others. Inkjet printing is a powerful digital tool for the deposition of smart and functional materials on various substrates, allowing the development of electronic devices such as PDs on various substrates. In this work, inkjet-printed PD arrays, based on the organic thin-film transistor architecture, have been developed and applied for the indirect detection of X-ray radiation using a scintillator ink as an X-ray absorber. The >90% increase of the photocurrent of the PDs under X-ray radiation, from about 53 nA without the scintillator film to about 102 nA with the scintillator located on top of the PD, proves the suitability of the developed printed device for X-ray detection applications ; The authors thank FEDER funds through the COMPETE 2020 Programme and National Funds through FCT-Portuguese Foundation for Science and Technology under Strategic Funding UID/FIS/04650/2013 and projects PTDC/EEI-SII/5582/2014, PTDC/CTM-ENE/5387/2014 and in the framework of EuroNanoMed 2016 call, Project LungChek ENMed/0049/2016. J.O. and V.C. thank the FCT for the SFRH/BD/98219/2013 and SFRH/BPD/97739/2013 grants, respectively. The authors acknowledge funding by the Spanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2016-76039-C4-3-R. Financial support from the Basque Government Industry Department under the ELKARTEK program is also acknowledged. The authors thank Iain McCulloch and Martin Heeney from Flexink for providing the OSC. Dirk Rittrich (Department Layer Deposition at Fraunhofer ENAS) is acknowledged for the FIB/SEM analysis and the sample preparation. R.D.R acknowledges the DFG Unit FOR1317 SMINT, the Cluster of Excellence, and the Tomsk Polytechnic University Competitiveness Enhancement Program grant TPU CEP_IHTP_73\2017. This work was performed in the ...