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The cost of specialized scientific equipment can be high and with limited funding resources, researchers and students are often unable to access or purchase the ideal equipment for their projects. In the fields of materials science and mechanical engineering, fundamental equipment such as tensile testing devices can cost tens to hundreds of thousands of dollars. While a research lab often has access to a large-scale testing machine suitable for conventional samples, loading devices for meso- and micro-scale samples for in-situ testing with the myriad of microscopy tools are often hard to source and cost prohibitive. Open-source software has allowed for great strides in the reduction of costs associated with software development and open-source hardware and additive manufacturing have the potential to similarly reduce the costs of scientific equipment and increase the accessibility of scientific research. To investigate the feasibility of open-source hardware, a micro-tensile tester was designed with a freely accessible computer-aided design package and manufactured with a desktop 3D-printer and off-the-shelf components. To our knowledge this is one of the first demonstrations of a tensile tester with additively manufactured components for scientific research. The capabilities of the tensile tester were demonstrated by investigating the mechanical properties of Graphene Oxide (GO) paper and thin films. A 3D printed tensile tester was successfully used in conjunction with an atomic force microscope to provide one of the first quantitative measurements of GO thin film buckling under compression. The tensile tester was also used in conjunction with an atomic force microscope to observe the change in surface topology of a GO paper in response to increasing tensile strain. No significant change in surface topology was observed in contrast to prior hypotheses from the literature. Based on this result obtained with the new open source tensile stage we propose an alternative hypothesis we term ‘superlamellae consolidation’ to explain the initial deformation of GO paper. The additively manufactured tensile tester tested represents cost savings of >99% compared to commercial solutions in its class and offers simple customization. However, continued development is needed for the tensile tester presented here to approach the technical specifications achievable with commercial solutions. [ABSTRACT FROM AUTHOR]

In this study, the facile dry transfer of silver nanowires (AgNWs) to a paper substrate using a dry film photoresist (DFR) was explored. No-primer-treated polyethylene terephthalate (NP-PET) with low adhesion strength and DFR were used as the carrier substrate and transfer medium for the AgNWs, respectively. Because of the lower adhesion of DFR to NP-PET than to paper, the DFR-coated AgNWs on NP-PET were successfully transferred to the paper substrate using simple hot pressing. The fabricated AgNW/DFR/paper electrodes were highly reliable without degradation in their electrical conductivity after 1000 bending cycles, and their feasibility as flexible electrodes was confirmed by demonstrating the operation of a light-emitting diode and flexible thin-film heater. [ABSTRACT FROM AUTHOR]

Practical applications require scalable, low cost and facile approaches to fabricate coatings that are repellent to liquids and yet are resistant to mechanical impact and abrasion which may occur during service operation of these materials. Here we report fabrication of superhydrophobic (SHP) coatings on paper substrates by one-step spray-coating of fluorinated silica nanoparticles. The coatings were extremely repellent to water and organic liquids with surface tensions higher than ~ 45 mN/m, as demonstrated by the sliding angles that are lower than 5°. The coated paper substrates retained their liquid repellency behavior without any discernable change in their static contact and sliding angles following different mechanical wear tests. Mechanical robustness together with demonstrations in self-cleaning, anti-icing and food-packaging show great promise for the use of fabricated paper substrates in different applications. A significant finding of the present work is that the mechanical robustness of the spray-coated fluorinated silica nanoparticles in the absence of any polymeric matrix/binder was dramatically higher on paper in comparison to flat substrates. These results suggest that the inherent microstructure of the paper provides a suitable matrix for protecting the functionalized nanoparticles against external mechanical effects and present an effective strategy for improving the mechanical robustness of the coatings fabricated by one-step spray-coating of nanomaterials. [ABSTRACT FROM AUTHOR]

Giving paper and polymer photochromic properties under laser irradiation is challenging due to the low resistance of these materials to heat, their flexibility, and their possibly irregular structure. However, we could successfully deposit TiO2/Ag/ TiO2 layers stacking on flexible white glossy paper and transparent polyethylene terephalate (PET) substrates using a reactive magnetron sputtering technique, and tailor coloration changes after laser irradiation, alternating visible and ultraviolet (UV) wavelengths. The sample colors are characterized by a panel of chromas depending on the irradiation conditions. We demonstrate that these chroma changes are due to morphological changes of Ag nanoparticles (NPs) after visible laser irradiation of the colored as-deposited sample. The process exhibits a good reversibility after subsequent UV irradiation due to the growth of new metallic Ag NPs. The colors displayed in diffuse reflection by the paper samples are more saturated than the ones displayed in regular transmission by PET samples. We demonstrate the efficiency of the photochromic process on such support by printing high resolution patterns exhibiting different colors depending on the observation conditions. [ABSTRACT FROM AUTHOR]

Paper is a cheap substrate which is in principle compatible with the process temperature applied in the plasma enhanced chemical vapour deposition (PECVD) and hot wire CVD (HWCVD) of thin film silicon solar cells. The main drawback of paper for this application is the porosity due to its fibre like structure. The feature size (micrometre scale) is larger than the thickness of the applied photovoltaic layers. To overcome this problem, UV curable lacquer was used to planarize the surface. Plain 80 grams printer paper was taken as a substrate and the lacquer smoothens the rough surface of the paper such that a designed nanostructure can be imprinted for light scattering. In this manner single junction amorphous silicon solar cells with a HWCVD deposited intrinsic layer were processed on paper, without any concessions to the process temperature of 200 °C. The cell performance is comparable to that of reference cells grown on stainless steel, proving that solar cells can be deposited on paper substrates without sacrificing performance. PV on paper could be applied as "disposable" power source for gadgets, electronic labelling, remote sensing systems, etc. (Internet of Things). [ABSTRACT FROM AUTHOR]

Conductivity of the poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) strongly depends on the film morphology, which can be altered by the presence of polyelectrolytes. Aqueous dispersion of PEDOT:PSS was studied with anionic sodium polyacrylate (PA) and cationic poly(dimethyldiallylammonium chloride) (pDADMAC) polyelectrolytes that are typically used in papermaking as retention aids and dispersing agents in the paper pigment coating formulations. Spin-coated PEDOT:PSS films on a PA coated glass formed non-uniform layers with lowered conductivity compared to the reference PEDOT:PSS films on a clean glass substrate. On contrary, spin-coated PEDOT:PSS on a pDADMAC coated glass formed uniform layers with good conductivity. These results point out the importance of surface chemistry when using renewable and recyclable paper-based substrates with the PEDOT:PSS films. [ABSTRACT FROM AUTHOR]

ABSTRACT A novel strategy via paper as an effective substrate has been introduced as a thermoelectric material in this work. Free-standing poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/paper composite films are conveniently prepared by a one-step method of directly writing PEDOT:PSS solution on paper, making the process simple, rapid, and facile. The free-standing composite films display excellent flexibility, light weight, soaking stability in water, and great potential in large-scale production. Improved thermoelectric properties are obtained in PEDOT:PSS/paper composite films, owing to the simultaneously enhanced Seebeck coefficient (30.6 μV K−1) and electrical conductivity, and a low thermal conductivity (0.16 W m−1 K−1) compared with pristine PEDOT:PSS films. The results indicate that paper as an effective substrate is suitable for the preparation of high-performance and flexible thermoelectric materials. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 737-742 [ABSTRACT FROM AUTHOR]

A custom peel testing device has been developed to measure adhesion strength of flexible thin film layers. The device overcomes the inherent problems of traditional peel machines that are associated with inaccurate peel angle definition and complex sample clamping. To demonstrate its performance, we have compared peel adhesion of currently used paper-based and polymer-based banknotes. Polymer banknotes have shown higher peel strength, which may yield greater durability and ensure increased lifetime in intensive use during circulation. [ABSTRACT FROM PUBLISHER]

Highlights: [•] Paper/caseinate and paper/caseinate/chitosan films were developed. [•] Chitosan layer on dry caseinate-coated paper provided the best functional properties. [•] Chitosan significantly increased the elongation at break of coated paper. [•] Caseinate/chitosan bilayer systems seemed to be appropriate paper coating materials. [ABSTRACT FROM AUTHOR]

Hydroxypropyl methylcellulose (HPMC)-coated papers without plasticizer and plasticized with polyols were prepared, and the effects of coating weight, different plasticizers (glycerol (GLY), sorbitol (SOR), and polyethylene glycol (PEG)), and plasticizer contents (20% to 50%) on the physical and mechanical properties of the resulting biopolymer-coated papers were studied. Coating weight was the most important factor affecting mechanical properties. Conversely, increasing coating weight led to a decrease in gloss and to an increase in tensile strength (TS), elongation at break (%E), and tearing resistance of coated papers. The application of unplasticized HPMC coatings (3 g/m²) on paper reduced water vapor permeability (WVP) and water absorption capacity by 25% as compared with uncoated paper. All plasticizers significantly (p < 0.05) increased WVP and Cobb60 values of the films. With the exception of PEG, no effect was found with plasticizers on TS and %E of coated papers compared with those without plasticizer. HPMC-coated papers with PEG as a plasticizer showed significantly lower TS and higher %E and tearing resistance than the other plasticized films (p < 0.05). HPMC coating improved tensile properties and tearing resistance of paper and could be regarded as a reinforcement layer. [ABSTRACT FROM AUTHOR]

The influence of type and content of modified montmorillonite (MMT) clay and amount of compatibilizing agent on physical-mechanical properties of polypropylene (PP)/organoclay films were studied. An unexpected decrease in tensile elastic modulus and yield stress was observed, and a striking drop in film density. SEM micrographs showed film microcavitation at polymer/clay interfaces. Experimental design analysis indicated that the most important parameter was the organoclay content: the higher the proportion of MMT, the lower the values of film properties. The addition of compatibilizer promoted an improvement in these film properties, probably due to the formation of less porous film. [ABSTRACT FROM AUTHOR]

A new method for making superhydrophobic (SH) paper based on spraying a nanocomposite film is developed. Furthermore, manipulating the wetting characteristics of SH paper has been demonstrated through a new method, i.e.printing solid grey patterns of different intensities with simple printing technology (home or office grade ink-jet and laser printers). It has been found that for a range of ink intensities (0–85%), water drop mobility can be changed at a different rate (almost independently) from repellency. The repellency of water decreases minimally up to 85% ink intensity with a sharp decrease up to 100% ink intensity. Drop mobility remains constant up to 30% ink intensity with a steady decrease up to 100% ink intensity. It was observed that using ink-jet or laser printing would yield different results for the change of mobility or repellency with higher amounts of ink/toner used. Being able to achieve almost independent control of water drop mobility over water drop repellency on SH paper would allow inexpensive lab-on-paper devices to be used for sampling, mixing and transport of liquids. [ABSTRACT FROM AUTHOR]

Abstract: Electrodeposition of poly(3,4-ethylenedioxythiophene) doped with chloride (PEDOT-Cl) on a paper substrate is demonstrated. A fully printed silver/polyaniline (Ag/PANI) layer-by-layer structure on a pigment coated paper acted as a working electrode, on which a layer of PEDOT-Cl was galvanostatically grown in an electrochemical cell. The deposited PEDOT-Cl appeared as a dark-blue circular area on a green Ag/PANI electrode. The electrodeposition was further confirmed by chemical and topographical analyses. The results demonstrate the potential of low-cost paper substrates and roll-to-roll mass-manufacturing methods in electrochemical applications. [ABSTRACT FROM AUTHOR]

This paper discusses the use of etalons fabricated from prepared glass slides to quantify the dimensional stability of two adhesive materials in damp environments. This technique facilitated the screening of adhesives for a kinematically demanding application. In addition to describing the etalon technique, additional data are provided on the performance of the device with the selected adhesives. One of the adhesives is simply identified as a cationic cured adhesive, while the other adhesive was Loctite 3615. A range of adhesive bond gaps from 50 to 500 μm was examined for the adhesive that showed the least displacement resulting from environmental aging. The results of this testing were applied to a kinematically sensitive device for verification of the adhesives use in this geometry. [ABSTRACT FROM AUTHOR]

In usual dry laser cleaning of opaque samples, short laser pulses are projected onto the sample surface to be cleaned. Energy transferred from light ejects extraneous particles away from the surface. Laser beam fluence is limited by the damage reached by high temperature that the sample surface can produce. We have experimentally shown that for thin samples, the thermo-elastic wave propagates within the whole sample thickness, thus also the rear surface, while temperature effects are limited to the front surface. Therefore, the proposed “verso” laser cleaning technique (the pulsed laser beam impinges on rear sample surface) can be applied to any opaque “mechanically thin” film and is useful for samples having delicate treatments on the surface to be cleaned (e.g. written paper, painted tiles, magnetic films). We have applied our technique to paper sheets showing that it is possible to efficiently clean the surface without damaging ink marks on it. Using a probe beam deflection (PBD) technique in both direct and reverse configuration we have shown that the “verso” cleaning effect is due to the higher penetration depth of the thermo-elastic wave with respect to the temperature profile propagation. [Copyright &y& Elsevier]

Recently, flexible intelligent wearable devices are in highly demand and it is urgent to increase the flexibility of traditional devices. Organometallic trihalide perovskite materials have become a hot spot in the photoelectric field due to its outstanding optoelectronic properties, which can be crystallized from solutions and vapors. Herein, we demonstrated a simple approach to flexible thin CH 3 NH 3 PbI 3 perovskite films on paper substrates using a dual-source physical vapor deposition method and a brush-coating method. The photodetector devices from the two methods have similar photodetecting and repeatable performances. They well maintained the optoelectronic functionality under bending conditions. Typically, up to 75% of its initial photocurrent was remained after 500 bending cycles, demonstrating good stability against bending deformation. Additionally, a 6 × 6 perovskite photodetector array based on stretchable origami-based techniques were fabricated. It has excellent all-optical acquisition capability and provides potential application in three-dimensional photo sensing. [Display omitted] • Thin perovskite films were deposited on paper substrates using both vapor and solution methods. • The paper-based photodetectors demonstrated good stability against bending deformation, even up to 500 bending cycles. • An origami-based perovskite photodetector array has excellent all-optical acquisition capability. [ABSTRACT FROM AUTHOR]

ZnO thin films were deposited on paper substrates by radio frequency magnetron sputtering at room temperature. By appropriate controlling the sputtering pressure, highly oriented (002) ZnO film with large grain size and low defect density can be obtained. Metal-semiconductor-metal structure ultraviolet photodetectors (UVPDs) were fabricated based on the ZnO/paper films and their optoelectronic response properties were investigated in detail. The optimum UVPD exhibits high UV sensitivity, showing peak responsivity at 380 nm. At applied voltage of 10 V, the UVPD has a high responsivity of 0.86 A/W and a high on/off ratio of ~600. Moreover, the flexible UVPD exhibits excellent stability and reproducibility under different bending conditions. The high flexibility of the UVPD was attributed to the compact and continuous properties of the sputtered film. The excellent operating characteristics make the UVPD a potential candidate for wearable UV meters and communication devices. • Paper based ultraviolet photodetector exhibits high flexibility and stability. • The paper substrate is renewable, biodegradable and abundant. • ZnO film was grown on paper at room temperature by magnetron sputtering. • Highly oriented (002) ZnO film was prepared with appropriate sputtering pressure. [ABSTRACT FROM AUTHOR]

In this study, the successful transfer of chemical vapor deposition (CVD)‐grown graphene on an ordinary printing paper surface is demonstrated. Pristine paper is not a suitable substrate for graphene transfer because of its fragile and hydrophilic nature against the chemicals used during the transfer process. Two different fluoroalkyl polymers, namely poly(hexafluorobutyl acrylate) (PHFBA) and poly(perfluorodecyl acrylate) (PPFDA) are coated on paper surfaces by an initiated CVD (iCVD) technique to make the paper surfaces hydrophobic. Hydrophobicity is found to be an important factor in order for the graphene to be transferred onto the paper substrate. Although surfaces coated with PPFDA possess better hydrophobicity owing to their longer perfluoroalkyl group and higher roughness, the graphene transfer is found to be more successful on a PHFBA‐coated surface. A thin film of PHFBA on the paper surface acts as a prime layer for effective and defect‐free transfer of graphene and makes the paper surface ideal and robust during the graphene transfer process. The as‐transferred graphene layer on the PHFBA‐coated paper surface shows high conductivity values, even after repeated folding and flattening cycles. [ABSTRACT FROM AUTHOR]