Poly(vinyl alcohol): formulation of a polymer ink for the patterning of substrates with a drop-on-demand inkjet printer

Nowadays, inkjet-printing technology is considered one of the most promising deposition techniques. It allows the highly precise deposition of functional materials to the required place on a substrate and a cost-saving printing process, especially when the drop-on-demand manner is used. Moreover, it represents the perfect technique for the controlled deposition of polymer material, especially for polymer solutions, because of their low viscosity and better process ability. Poly(vinyl alcohol) was chosen because of its versatile application potential; moreover, its compatibility with the human body only increases its usability in bio-applications. The main purpose of this research was to find the appropriate solvent system for poly(vinyl alcohol) and its printability. Solutions with the best properties were printed in pre-defined patterns and personally defined motifs and the printing conditions were optimized in order to obtain patterns with the best possible shape and resolution, which were analysed by optical microscopy.Ministry of Education; Youth and Sports of the Czech Republic - Program NPU I [LO1504]; Internal Grant Agency of Tomas Bata University in Zlin [IGA/CPS/2015/006

Fully inkjet-printed cuo sensor on flexible polymer substrate for alcohol vapours and humidity sensing at room temperature

This work focuses on an inkjet-fabricated sensor based on copper oxide nanostructured particles on polymer flexible substrate for the sensing of alcohol vapours and humidity at room temperature. Nanoparticles were prepared by a microwave-assisted solvothermal sealed vessel synthesis method. The ink composition was developed on the basis of viscosity and surface tension optimization by the addition of polymeric steric surfactant and dispersant. The printing process was optimized with the help of non-dimensional criteria. Silver nanoink was used for the printing of an interdigitated pattern on a PET substrate which was overprinted by the copper oxide ink, thus obtaining a flexible flat sensor. Material design and all fabrication steps of the sensor respected the temperature limitation given by the thermal stability of the polymer substrate. Printed layers and motifs were characterized microscopically and by resistance measurement. The effectiveness of the prepared sensor was demonstrated and studied by measuring the response to saturated vapours at room temperature. The sensing layer showed the opposite resistance response to stimuli than expected for the well-known p-type sensing mechanism of CuO sensors operated at high temperatures. In addition to vapour sorption, condensation and desorption influencing electron, proton and ionic conductivity, manifestation of another mechanism was observed and an explanation suggested in terms of the electrochemical mechanism. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.Ministry of Education, Youth and Sports of the Czech Republic-Program NPU I [LO1504]; Internal Grant Agency of Tomas Bata University in Zlin [IGA/CPS/2015/006, IGA/CPS/2016/007, IGA/CPS/2017/008

PEDOT: PSS thermoelectric generators printed on paper substrates

Flexible electronics is a field gathering a growing interest among researchers and companies with widely varying applications, such as organic light emitting diodes, transistors as well as many different sensors. If the circuit should be portable or off-grid, the power sources available are batteries, supercapacitors or some type of power generator. Thermoelectric generators produce electrical energy by the diffusion of charge carriers in response to heat flux caused by a temperature gradient between junctions of dissimilar materials. As wearables, flexible electronics and intelligent packaging applications increase, there is a need for low-cost, recyclable and printable power sources. For such applications, printed thermoelectric generators (TEGs) are an interesting power source, which can also be combined with printable energy storage, such as supercapacitors. Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), or PEDOT:PSS, is a conductive polymer that has gathered interest as a thermoelectric material. Plastic substrates are commonly used for printed electronics, but an interesting and emerging alternative is to use paper. In this article, a printed thermoelectric generator consisting of PEDOT:PSS and silver inks was printed on two common types of paper substrates, which could be used to power electronic circuits on paper. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.Swedish Knowledge Foundation (KKS

Preparation and characterization of nanostructured thin films applicable in polymer light emitting devices

This work deals with a composite material based on polymer/inorganic nanoparticles applicable in organic electronics as an active layer. Prepared composite, containing conjugated polymer MEH-PPV as a matrix and ZnO nanoparticles (NPs) as filler, was characterized using spectroscopic and microscopic methods and it was used for preparation of polymer light emitting diodes. Creation of polymer/inorganic nanocomposite by incorporation of ZnO NPs in polymer matrix leads to better injection of negative charge carriers from cathode into active layer material and thus the achieved electroluminescence of prepared device has much higher intensity (in several orders) in comparison to devices with active layer from neat polymer. Moreover, excellent distribution and dispersion of NPs in polymer improve the homogeneity of radiation from whole device area. In our contribution, we introduce method how to easily improve performance of polymer light emitting diodes by preparation of nanocomposite based on ZnO nanoparticles incorporated into the conjugated polymer.ERDF, European Regional Development FundMinistry of Education, Youth and Sports of the Czech Republic Program NPU I [LO1504]; Operational Program Research and Development for Innovations; European Regional Development Fund (ERDF); national budget of Czech Republic, within the framework of project CPS - strengthening research capacity [CZ.1.05/2.1.00/19.0409]; Internal Grant Agency of Tomas Bata University in Zlin [IGA/CPS/2016/007

Water-based indium tin oxide nanoparticle ink for printed toluene vapours sensor operating at room temperature

This study is focused on the development of water-based ITO nanoparticle dispersions and ink-jet fabrication methodology of an indium tin oxide (ITO) sensor for room temperature operations. Dimensionless correlations of material-tool-process variables were used to map the printing process and several interpretational frameworks were re-examined. A reduction of the problem to the Newtonian fluid approach was applied for the sake of simplicity. The ink properties as well as the properties of the deposited layers were tested for various nanoparticles loading. High-quality films were prepared and annealed at different temperatures. The best performing material composition, process parameters and post-print treatment conditions were used for preparing the testing sensor devices. Printed specimens were exposed to toluene vapours at room temperature. Good sensitivity, fast responses and recoveries were observed in ambient air although the n-type response mechanism to toluene is influenced by moisture in air and baseline drift was observed. Sensing response inversion was observed in an oxygen and moisture-free N2 atmosphere which is explained by the charge-transfer mechanism between the adsorbent and adsorbate molecules. The sensitivity of the device was slightly better and the response was stable showing no drifts in the protective atmosphere. © 2018 by the authors. Licensee MDPI, Basel, Switzerland.CZ.1.05/2.1.00/19.0409; IGA/CPS/2015/006; IGA/CPS/2017/008; IGA/CPS/2016/007; LO1504, NPU, Northwestern Polytechnical University; FEDER, European Regional Development Fund; MŠMT, Ministerstvo Školství, Mládeže a Tělovýchovy; FEDER, European Regional Development Fund; Research and DevelopmentMinistry of Education, Youth and Sports of the Czech Republic-Program NPU I [LO1504]; Operational Program Research and Development for Innovations; European Regional Development Fund (ERDF); national budget of Czech Republic [CZ.1.05/2.1.00/19.0409]; Internal Grant Agency of Tomas Bata University in Zlin [IGA/CPS/2015/006, IGA/CPS/2016/007, IGA/CPS/2017/008

Electronic performance of printed PEDOT:PSS lines correlated to the physical and chemical properties of coated inkjet papers

PEDOT:PSS organic printed electronics chemical interactions with the ink-receiving layer (IRL) of monopolar inkjet paper substrates and coating color composition were evaluated through Raman spectroscopy mapping in Z (depth) and (XY) direction, Fourier transform infrared spectroscopy (FTIR) and energy dispersive X-ray spectroscopy (EDS). Other evaluated properties of the IRLs were pore size distribution (PSD), surface roughness, ink de-wetting, surface energy and the impact of such characteristics on the electronics performance of the printed layers. Resin-coated inkjet papers were compared to a multilayer coated paper substrate that also contained an IRL but did not contain the plastic polyethylene (PE) resin layer. This substrate showed better electronic performance (i.e., lower sheet resistance), which we attributed to the inert coating composition, higher surface roughness and higher polarity of the surface which influenced the de-wetting of the ink. The novelty is that this substrate was rougher and with somewhat lower printing quality but with better electronic performance and the advantage of not having PE in their composite structure, which favors recycling. © 2019 The Royal Society of Chemistry

Paper no P31: Optoelectronic properties of MEH-PPV thin films influenced by their thickness

In this paper, the influence of thickness on the optoelectricul properties of poly(2-metho.xy-5-(2'-ethyl-hexoxy)-1,4-phenyle-ne-vinylene) is discussed. The main goal of our measurements was to describe the relationship between thickness of films and their optoelecirical properties. We discovered that there is always certain minimum film thickness needed for development of conformational structure and for changes in optoelectricul behavior. © (2013) by SID-the Society for Information Display All rights reserved.CZ. 1.07/2.3.00/20.0104, ESF, European Social Fund; CZ.1.05/2.1.00/03.0111, ERDF, European Regional Development Fund; IGA/FT/2013/025, UTB, Univerzita Tomáše Bati ve Zlín

Paper no P20: Surface modification of ITO-coated PET foil for material printing

This paper deals with the improvement of adhesion of the ink to substrate surface. The treatment method based on chemical wav improves adhesion properties of JTO layer while its conductivity is preserved. There exists a time limit, where the ITO layer is eroded and the conductivity is decreasing. This time limit was revealed at 4 min. © (2013) by SID-the Society for Information Display All rights reserved.CZ.1.05/2.1.00/03.0111, ERDF, European Regional Development Fund; CZ.l.07/2.3.00/20.0104, ESF, European Social Fund; IGA/FT/2013/025, UTB, Univerzita Tomáše Bati ve Zlín

Polymeric ink for material printing

Polymerní inkoust pro materiálový tisk sestává z vodivého polymeru - poly(2-methoxy-5-(2-ethylhexyloxy)- 1,4-phenylenvinylenu) o koncentraci 0,2 až 0,4 % hmotn. ve směsi organických rozpouštědel a povrchově aktivního činidla - polyethylenglykol-p-(1,1,3,3-tetramethylbutyl)-phenyl-etheru v množství 3 až 4 % hmotn.Polymeric ink for material printing consists of conductive polymer poly(2-methoxy-5-(2-ethylhexyloxy)- 1,4-phenylenvinylene) with concentration ranging from 0,2 to 0,4 weight percent. Polymer is solved in the mixture of organic solvents with addition of surface activator polyethylenglykol-p-(1,1,3,3-tetramethylbutyl)-phenyl-ether in amount ranging from 3 to 4 weight percent related to total weight of solution

Inorganic ink based on nanoparticles, intended especially for material printing

Anorganický inkoust pro materiálový tisk sestává z nanočástic CuO o koncentraci 3 až 10 % hmotn. ve směsi polymerních dispergátorů v množství 5 až 35 % hmotn. a doplňujícího množství vody do 100 % hmotn. Anorganický inkoust na bázi nanočástic podle technického řešení má s výhodou nanočástice oxidu měďnatého o velikosti menší než 50 nm.Inorganic ink for material printing based on CuO nanoparticles with concentration ranging from 3 to 10 weight percent. For stabilization of nanoparticles were used polymeric dispersants with concentration ranging from 5 to 35 weight percent. The mixture was topped up to 100 percent by water. Inorganic ink based on nanoparticles consists of CuO nanoparticles diameter smaller than 50 nm