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Copyright: 2016 SPIE. Due to copyright restrictions, the attached PDF file only contains the abstract of the full text item. For access to the full text item, kindly consult the publisher's website.

Copyright: 2017 SPIE. Due to copyright restrictions, the attached PDF file only contains the abstract of the full text item. For access to the full text item, kindly consult the publisher's website.

Graphene paper has diverse applications in printed circuit board electronics, bioassays, 3D cell culture, and biosensing. Although development of nanometal-graphene hybrid composites is commonplace in the sensing literature, to date there are only a few examples of nanometal-decorated graphene paper for use in biosensing. In this manuscript, we demonstrate the synthesis and application of Pt nano cauliflower-functionalized graphene paper for use in electrochemical biosensing of small molecules (glucose, acetone, methanol) or detection of pathogenic bacteria ( Escherichia coli O157:H7). Raman spectroscopy, scanning electron microscopy and energy dispersive spectroscopy were used to show that graphene oxide deposited on nanocellulose crystals was partially reduced by both thermal and chemical treatment. Fractal platinum nanostructures were formed on the reduced graphene oxide paper, producing a conductive paper with an extremely high electroactive surface area, confirmed by cyclic voltammetry and electrochemical impedance spectroscopy. To show the broad applicability of the material, the platinum surface was functionalized with three different biomaterials: 1) glucose oxidase (via chitosan encapsulation); 2) a DNA aptamer (via covalent linking), or 3) a chemosensory protein (via his linking). We demonstrate the application of this device for point of care biosensing. The detection limit for both glucose (0.08 ± 0.02 μM) and E. coli O157:H7 (1.3 ± 0.1 CFU mL -1 ) were competitive with, or superior to, previously reported devices in the biosensing literature. The response time (6 sec for glucose and 10 min for E. coli ) were also similar to silicon biochip and commercial electrode sensors. The results demonstrate that the nanocellulose-graphene-nanoplatinum material is an excellent paper-based platform for development of electrochemical biosensors targeting small molecules or whole cells for use in point of care biosensing.

In this paper, we demonstrate a combination of foil and InkJet printed structures in Lab-on-Paper device. Such a device can be used to analyze a concentration of salt in water (or any other substance) by measuring the impedance of the analyte. Lab-on-Paper can perform an analysis on a microscopic volume of substances. Their advantages is low price, small size or can be easy disposable or stored. In the paper was presented manufacturing and testing of device with colorimetric pH testers and impedance measurement.

Using a so called pulsetrode concept and two identical ion selective electrodes (ISEs), the concentration of alkali metal ions can be measured without using a reference electrode. This measurement method was demonstrated recently, using all organic ISEs which have been fabricated by simplest means on a plain sheet of paper. Though, this low-cost, all organic ion sensing platform exhibited excellent stability over three months, it required a time consuming conditioning prior to measurement (>1 h). Here, we present a new measurement method which employs a square wave current rather than a single current pulse which is followed by a long regeneration time. This method reduces the conditioning time to 6 minutes, using the same low-cost sensing platform. Furthermore, after the initial conditioning, a quasi continuous measurement is possible. Additionally, using ISEs with different surface areas, a low-cost and simple threshold sensor is demonstrated.

Conservation of cultural heritage treasures is the most important issue for transferring knowledge to the public through the next generation of students, academics, and researchers. Although this century is authenticating e-books and information by means of electronic text, still historical manuscripts as content as well as objects are the main original recourses of keeping a record of this transformation. The current work focuses on cleaning paper samples by the application of pulsed light, which is interventional. Experiments carried out using paper samples that are artificially colonized with Ulocladium chartarum. Paper is treated by Nd:YAG laser light. The available wavelength is 1064 nm, at various fluences, repetition rates and number of pulses. Two types of paper are stained with fungi colonies, which grow on substrates of clean paper, as well as on paper with ink text. The first type of paper is Whatman No.1056, which is closer to pure cellulose. The second type of paper is a page of a cultural heritage book published in 1926. Cleaning is performed using laser irradiation, thus defining the damage threshold of each sample. The treatment on paper Watman showed a yellowing, especially on areas with high concentration of fungi. The second sample was more durable to the exposure, performing the best results at higher fluences. Eventually, the paper samples are characterized, with optical microscopy and SEM/EDX analyses, prior to and after cleaning.

The tone value increase in halftone printing commonly referred to as dot gain actually encompasses two fundamentally different phenomena. Physical dot gain refers to the fact that the size of the printed halftone dots differs from their nominal size, and is related to the printing process. Optical dot gain originates from light scattering inside the substrate, causing light exchanges between different chromatic areas. Due to their different intrinsic nature, physical and optical dot gains need to be treated separately. In this study, we characterize and compare the dot gain properties for offset prints on coated and uncoated paper, using AM and first and second generation FM halftoning. Spectral measurements are used to compute the total dot gain. Microscopic images are used to separate the physical and optical dot gain, to study ink spreading and ink penetration, and to compute the Modulation Transfer Function (MTF) for the different substrates. The experimental results show that the physical dot gain depends on ink penetration and ink spreading properties. Microscopic images of the prints reveal that the ink penetrates into the pores and cavities of the uncoated paper, resulting in inhomogeneous dot shapes. For the coated paper, the ink spread on top of the surface, giving a more homogenous dot shape, but also covering a larger area, and hence larger physical dot gain. The experimental results further show that the total dot gain is larger for the uncoated paper, because of larger optical dot gain. The effect of optical dot gain depends on the lateral light scattering within the substrate, the size of the halftone dots, and on the halftone dot shape, especially the dot perimeter.

We built a hyperspectral imaging apparatus using middle-infrared light of 8–14 μm, which has a strong ability to identify organic materials, and attempted visualization of the distribution of organic materials that could not be identified by a naked eye. For this purpose, we utilized a low-cost bolometer camera (Nippon Avionics co., ltd. C100V, Japan) for its easy availability rather than an expensive mercury cadmium telluride (MCT) array sensor. To compensate for the low sensitivity of this bolometer, we adopted a Fourier-type spectroscopic system (Aoi Electronics co. ltd., Japan) using an imaging interferometer devised by the Kagawa University, Japan; this interferometer has higher light-utilization efficiency than Michelson interferometers, which are used in popular interferometry techniques. In this study, 4 types of adhesives, 9 types of varnishes and more than 50 types of inks were put on Al plates of size 10 cm × 10 cm and were used as samples. Glossy paper for printing photos with an inkjet printer was also used as a sample. A 300 °C black body of size 15 cm × 15 cm was used as a light source. Spectra of 320 × 240 points were measured at a wavelength resolution of approximately 9 cm−1. The mirror was scanned only once. The measurement time was approximately 30 s. Hyperspectral images of adhesives, varnishes and inks on Al plate and paper were successfully measured. Spectra over a 5 × 5-pixel neighborhoods were averaged, and the averaged spectra were compared with those measured by a commercially available Fourier transform infrared (FTIR) spectroscopy. The averaged and measured spectra had absorption peaks at the same wavelengths. Furthermore, by analyzing the measured spectra, the distribution of substances invisible to the naked eye was visualized. Our results show that if low-absorbance organic materials are put on a high-reflectance surface such as an Al plate, the middle-infrared hyperspectral imaging could be measured using a bolometer. Additionally, hyperspectral imaging of high-reflectance paper, such as glossy paper, could also be measured. Because a bolometer camera is much cheaper than an MCT array, hyperspectral imaging with such a camera has many potential applications. Moreover, an imaging interferometer, with its high efficiency of light utilization, is very suitable for the purpose.

In this work we present a promising method for fabrication of conductive tracks on paper based substrates by laser assisted reduction of Graphene Oxide (GO). Printed electronics on paper based substrates is be coming more popular due to lower cost and recyclability. Fabrication of conductive tracks is of great importance where metal, carbon and polymer inks are commonly used. An emerging option is reduced graphene oxide (r-GO), which can be a good conductor. Here we have evaluated reduction of GO by using a 532 nm laser source, showing promising results with a decrease of sheet resistance from >100 M Ω/Sqr for unreduced GO down to 126 Ω/Sqr. without any observable damage to the paper substrates.

Microfluidic paper-based analytical devices decorated with ZnO nanospherical (nanoSPs) aggregates (ZnO-μPAD) for glucose detection have been fabricated. ZnO nanoSPs were prepared by wet chemical synthesis and integrated on the optimized geometry of ZnO-μPAD has 0.2 and 0.4 mm of channel width and length, respectively. Glucose detection measurements were based on electrochemical and infrared transmission measurements. The glucose concentrations were adjusted as 5, 6.5, and 9 mmol, i.e. typical glucose level for normal, pre-diabetes and diabetes, in a mixture of ringer lactate as simulated biological fluid and red blood cells. ZnO nanoSPs in this study possess an average aggregate size of 160 nm formed by clustered ~ 18 nm crystallite size and ordered porous matrix as well as a surface area of 15 m2·g-1.The separation process of the glucose sample on ZnO-μPAD requires approximately 45 s. The glucose detection results show that both electrochemical-based and FTIR-based measurements perform a linear measurement system (R2 of 0.81 to 0.99) with a relatively high sensitivity. A linearly decreasing impedance spanning from 2.2 – 0.6 Ohm and linearly increasing ΔIR transmission spanning from 3 – 19% are obtained for glucose level ranging from 5 – 9 mmol.

Special fiber Bragg grating (FBG) sensor embedding and interrogation schemes have been designed to capture the momentary peak pressure forces in the nip of adjacent paper machine rolls, and the spatial distribution of these nip forces along circumference and length of the roll, for production speeds of up to 2000 m/min. Additionally, this FBG sensor system measures the temperature distribution in the roll cover. FBG sensor embedment has been investigated and optimized for the implementation of pressure force measurements in various roll cover materials. These measurements enable immediate quality control during various stages of the production process. Draw Tower Grating sensor arrays, simultaneously performing spectrometric interrogation, and autonomous power supply technologies result in an extremely robust fiberoptic sensor system operating at rotation speeds of 700 rpm, equivalent to centrifugal accelerations of 300 G.

The development of a paper-based analytical device (PAD) for assessing personal exposure to particulate metals will be presented. Human exposure to metal aerosols, such as those that occur in the mining, construction, and manufacturing industries, has a significant impact on the health of our workforce, costing an estimated $10B in the U.S and causing approximately 425,000 premature deaths world-wide each year. Occupational exposure to particulate metals affects millions of individuals in manufacturing, construction (welding, cutting, blasting), and transportation (combustion, utility maintenance, and repair services) industries. Despite these effects, individual workers are rarely assessed for their exposure to particulate metals, due mainly to the high cost and effort associated with personal exposure measurement. Current exposure assessment methods for particulate metals call for an 8-hour filter sample, after which time, the filter sample is transported to a laboratory and analyzed by inductively-coupled plasma (ICP). The time from sample collection to reporting is typically weeks and costs several hundred dollars per sample. To exacerbate the issue, method detection limits suffer because of sample dilution during digestion. The lack of sensitivity hampers task-based exposure assessment, for which sampling times may be tens of minutes. To address these problems, and as a first step towards using microfluidics for personal exposure assessment, we have developed PADs for measurement of Pb, Cd, Cr, Fe, Ni, and Cu in aerosolized particulate matter.

Roughness of a paper surface is particularly important in paper and board destined to be printed. Surfaces are often coated and the amount of coating and method of application used depends on the roughness of the base paper. We present a method of measure of the roughness of the paper based in the analysis of speckle pattern on the surface. Images are captured by means of a simple configuration using a laser and a camera CCD. Then, we apply digital image processing using the co-occurrence matrix, so this method can be considered as a non-contact surface profiling method, that can be used online.

Today there is a strong interest in the scientific and industrial community concerning the use of biopolymers for electronic applications, mainly driven by low-cost and disposable applications. Adding to this interest, we must recognize the importance of the wireless auto sustained and low energy consumption electronics dream. This dream can be fulfilled by cellulose paper, the lightest and the cheapest known substrate material, as well as the Earth's major biopolymer and of tremendous global economic importance. The recent developments of oxide thin film transistors and in particular the production of paper transistors at room temperature had contributed, as a first step, for the development of disposable, low cost and flexible electronic devices. To fulfil the wireless demand, it is necessary to prove the concept of self powered devices. In the case of paper electronics, this implies demonstrating the idea of self regenerated thin film paper batteries and its integration with other electronic components. Here we demonstrate this possibility by actuating the gate of paper transistors by paper batteries. We found that when a sheet of cellulose paper is covered in both faces with thin layers of opposite electrochemical potential materials, a voltage appears between both electrodes -paper battery, which is also self-regenerated. The value of the potential depends upon the materials used for anode and cathode. An open circuit voltage of 0.5V and a short-circuit current density of 1μA/cm 2 were obtained in the simplest structure produced (Cu/paper/Al). For actuating the gate of the paper transistor, seven paper batteries were integrated in the same substrate in series, supplying a voltage of 3.4V. This allows proper ON/OFF control of the paper transistor. Apart from that transparent conductive oxides can be also used as cathode/anode materials allowing so the production of thin film batteries with transparent electrodes compatible with flexible, invisible, self powered and wireless electronics.

We have developed thin and light weight flexible EPD (electronic paper display) using QR-LPD technology. QR-LPD suits for flexible display because of its simple display structure (no TFT) and robust image holding property. Novel types of thin and light weight flexible electronic paper display are discussed. This technology can realize the "real paper like" flexible electronic paper.

We report the development of a novel, low-cost surface enhanced Raman spectroscopy (SERS) substrate that is fabricated by ink-jet-printing silver nanostructures into cellulose paper. Analysis of a liquid sample is performed by spotting a 1 microliter droplet onto the printed SERS substrate. The droplet is contained within a small area of the SERS substrate by ink-jet-printing hydrophobic barriers to define microfluidic boundaries. Using Rhodamine 6G as the analyte, we are able to measure a strong SERS fingerprint signal when only 10 femtomoles of analyte are applied to the paper.

Laser ablation offers cleaning method for historical and art works effectively. Difference between ablation threshold of contamination layer and the surface yields to remove contaminants from surface without detriment to historical material. In particular, lasers with ultrashort pulse duration are very convenient for brittle historical papers, fibers of which should be intact after cleaning treatment. Since duration of laser irradiation and material interaction is very short, the possibility of damage to the paper is very low. One of the other crucial issues after paper cleaning treatment is color variation on the surface. Authentic color of the historical paper has to be preserved after the procedure. In this paper, we present results of paper cleaning via femtosecond (fs) laser running at a wavelength of 1030 nm. In the first stage of this experimental study, we determined optimum laser parameters on artificially soiled and aged paper samples, then cleaned a handwritten manuscript with ‘sizing’. In calligraphy, ornamentation and miniature arts, sizing is applied on paper as a protective layer which increases strength of paper and renders it more useful. Papers with sizing have been prevalently used in Islamic or Ottoman culture. We observed that after laser irradiation, artificial soling layer is effectively removed, while original color of the subs-layers did not alter. We used scanning electron microscopy (SEM) to examine fiber integrity, and determined that the sizing layer was not removed when optimized parameters were used, thus the fibers were not damaged.

Therapeutic drug monitoring (TDM) contributes to safe and effective pharmacotherapy in clinical fields. A simple, rapid, low-cost, and minimally-invasive drug measurement method attracts much interest for point-of-care TDM. Tear fluids can be collected minimally-invasively compared to blood sampling and there is a correlation between a drug concentration in tears and that in bloods. Surface enhanced Raman spectroscopy (SERS) with paper-based substrate is useful for point-of-care TDM owing to inexpensiveness and high-sensitivity. Paper is also a safe tear collection tool. Then we are studying on a paper-based SERS of tear specimen for point-of-care TDM. In this paper, to improve sensitivity in measuring drug concentration in tear fluids, we fabricated a SERS substrate by coating gold nano-rods on a paper substrate and evaluated whether the fabricated substrate can enhance Raman scattering. Sodium phenobarbital (PB), an anti-convulsant agent, was used as a target. In experiment, the fabricated substrate indicated the lower detection limit of PB in a solution than a plain paper substrate. This result showed the potential of the paper based SERS substrate to measure drug concentration in tears simply and inexpensively.

As a bio/chemical sensing technique, surface enhanced Raman spectroscopy (SERS) offers sensitivity comparable to that of fluorescence detection while providing highly specific information about the analyte. Although single molecule identification with SERS was demonstrated nearly 20 years ago, today a need exists to develop practical solutions for point‐of‐sample and point‐of‐care SERS systems. Recently, we demonstrated the fabrication of SERS substrates by inkjet printing silver and gold nanostructures onto paper and other microporous membranes. Using these devices, we have been able to achieve detection limits comparable to conventional nanofabricated plasmonic substrates. Furthermore, we leverage the fluidic properties of paper to enhance the performance of the SERS devices while also enabling unprecedented ease of use. Here we report the use of inkjet‐fabricated paper SERS substrates as a detection device for biological macromolecules in an easy‐to‐use format with a low number of steps. The targeted biomarker is specifically detected with SERS through a single step competitive displacement, which dramatically reduces the number of steps as compared to conventional assays. Moreover, we further improve the usability of the assay by incorporating a paper SERS device with a fluidic cartridge format. The wicking nature of the paper sensor eliminates manual sample application steps and is much simpler than the world‐to‐chip interface of microfluidic devices. The introduction of this paper‐based SERS assay is a significant step towards highly sensitive, low‐cost, and, importantly, easy to use multiplexed biological assays.

There are two main challenges in producing a robust, paper-based analytical device. The first one is to create a hydrophobic barrier which unlike the commonly used wax barriers does not break if the paper is bent. The second one is the creation of the (bio-)specific sensing layer. For this proteins have to be immobilized without diminishing their activity. We solve both problems using light-based fabrication methods that enable fast, efficient manufacturing of paper-based analytical devices. The first technique relies on silanization by which we create a flexible hydrophobic barrier made of dimethoxydimethylsilane. The second technique demonstrated within this paper uses photobleaching to immobilize proteins by means of maskless projection lithography. Both techniques have been tested on a classical lithography setup using printed toner masks and on a lithography system for maskless lithography. Using these setups we could demonstrate that the proposed manufacturing techniques can be carried out at low costs. The resolution of the paper-based analytical devices obtained with static masks was lower due to the lower mask resolution. Better results were obtained using advanced lithography equipment. By doing so we demonstrated, that our technique enables fabrication of effective hydrophobic boundary layers with a thickness of only 342 μm. Furthermore we showed that flourescine-5-biotin can be immobilized on the non-structured paper and be employed for the detection of streptavidinalkaline phosphatase. By carrying out this assay on a paper-based analytical device which had been structured using the silanization technique we proofed biological compatibility of the suggested patterning technique.

Non-invasive measurement of paper porosity is an important problem for papermaking industry. Presently used techniques are invasive and require long time for processing the sample. In recent years optical coherence tomography (OCT) has been proved to be an effective tool for non-invasive study of optically non-uniform scattering media including paper. The aim of present work is to study the potential ability of OCT for sensing the porosity of a paper sample by means of numerical simulations. The paper sample is characterized by variation of porosity along the sample while numerical simulations allow one to consider the samples with constant porosity which is useful for evaluation of the technique abilities. The calculations were performed implementing Monte Carlo-based technique developed earlier for simulation of OCT signals from multilayer paper models. A 9-layer model of paper consisting of five fiber layers and four air layers with non-planar boundaries was considered. The porosity of the samples was varied from 30 to 80% by varying the thicknesses of the layers. The simulations were performed for model paper samples without and with optical clearing agents (benzyl alcohol, 1-pentanol, isopropanol) applied. It was shown that the simulated OCT images of model paper with various porosities significantly differ revealing the potentiality of the OCT technique for sensing the porosity. When obtaining the images of paper samples with optical clearing agents applied, the inner structure of the samples is also revealed providing additional information about the samples under study.

Surface enhanced Raman spectroscopy (SERS) requires the analyte molecule to be close to the plasmonic surface in order to generate SERS enhancement. This limitation restricts the practical application of SERS to molecules that possess functional groups that interact strongly with gold or silver surfaces. Moreover, the identification of target analytes in a complex sample matrix is made even more difficult when interferents compete with the target for binding to the plasmonic surface, resulting in overlapping spectral signatures. In this work, we report a strategy to functionalize inkjet printed P-SERS substrates by strategically placing supramolecular structures (such as nucleic acid aptamers) onto the gold nanoparticles. This promotes the selective interaction of target molecules with the plasmonic surface, leading to improved sensor performance.

Electro-Active Paper (EAPap) is attractive as an EAP actuator material due to its merits in terms of lightweight, dry condition, large displacement output, low actuation voltage and low power consumption. This paper presents the fabrication and performance test of EAPap actuators. EAPap material has been made from cellulose materials. Cellulose fiber is dissolved into a solution and made into a sheet by using a spin coater. Thin electrodes are deposited on the cellophane sheet to comprise an EAPap. Next the EAPap is made into plate or beam specimens cut along a specific orientation to enhance the actuator performance. The EAPap is clamped on electric power connector and placed in an environmental chamber and the tip displacement of EAPap is measured with laser sensor. Also the blocking force of EAPap sample is measured. The measured force is compared with a theoretical beam model. These measurements are performed under a variety of environmental and input factors including frequency, actuation voltage, temperature and humidity. Characteristics of EAPap in terms of fibrous nature, their crystallinity, and mechanical, physical and electrochemical characteristics are presented.

This work addresses the study of repeatability of an optical laser system, previously implemented by our research team, for characterization of the fiber distribution and mass density of two paper samples with different characteristics. In the experiment that has been carried out in the current work, both paper samples were laser scanned by the system on a total of 16 times (4 times per day in 4 different days). The data acquired and registered during the experimental work, associated to both tested samples, were then processed and the obtained results showed that the optical system is precise.

In this paper, a novel self-heating composite material utilizing carbon nanotubes (CNTs) paper is designed and fabricated successfully. The carbon nanotube paper was prepared by multiple steps of CNTs dispersion and suspension filtration as shown in Fig1. a and characterized by scanning electron microscopy thermo gravimetric analysis nitrogen adsorption isotherms at 77K and so on. The surface of the as-prepared CNTs paper is smooth and very flexible. The conductivity of the CNTs paper could be regulated from 30 S/cm to 200 S/cm. The fabricating process of the self-heating is shown in Fig.1 b and the electric heating performance under different ambient temperature, power changing from 4.3W to 44.8W and wind speed ranging from 8m/s to 14m/s was discussed. In addition, the feasibility of the application in the deicing of the composite was simulated by the software of Fluent. The thermal behavior was discussed combining the experimental and simulated values, especially the temperature field distribution under different wind speed. The maximum heating rate can reach 2℃/s under different condition. The equilibrium temperature and energy consumption of the composite at different power compared with the commercial kanthal electric heating film were also investigated. The energy consumption of the self-heating material is less than the kanthal electric heating film to reach the same equilibrium temperature which may be caused by the difference of heat capacity. The experimental and simulated results indicate the electric heating performance of CNTs paper-based composite is superior to the commercial kanthal electric heating film and has feasibility in the field of deicing.

In this present study experimental and finite element analysis of cellulose based electro-active paper energy harvester is presented. Electro-active paper coated with metal electrode is a smart form of cellulose and exhibit piezoelectric effect. Specimens were prepared by depositing electrodes on both sides of the cellulose film. A 50 mm x 50 mm cellulose film coated with aluminum electrodes was bonded on 100 mm x 50 mm x 1 mm aluminum host structure. The voltage output to input acceleration frequency response across a load resistor of 1 MΩ is recorded by conventional energy harvesting experimental setup at the fundamental vibration mode of the EAPap cantilever beam. A coupled piezoelectric-circuit finite element model is developed in which load resistor is directly connected to energy scavenging device. Voltage output FRF is measured for the cases, without proof mass, and by adding a 2 grams proof mass near the tip of the cantilever. The experimental voltage FRF value is 7.6 V/g at 75.1 Hz and is improved to 13.8 V/g at 62.2 Hz when a stainless steel proof mass of 2 grams is added. The presented CPC-FEM model results agree reasonably well with the experimental results. Despite the fact that the electro-mechanical coupling coefficient of electro-active paper is lower than other available piezoelectric materials, it is biocompatible, cheap and naturally occurring polymeric material. It is also very flexible and posses similar piezoelectric characteristics such a PVDF which inspire to use EAPap in energy harvesting applications.

Paper based composite with semiconductor nanomaterial is a fascinating orgnic-inorganic hybrid composite that has improved properties of flexibility, biocompatibility and functionality. Cellulose Electro-Active Paper (EAPap) is a kind of paper electric device. To improve functionality of EAPap, ZnO is used as hybrid inorganic composition. Cellulose- ZnO hybrid nanocomposite (CEZOHN) is fabricated by seeding and growing ZnO on cellulose film with a simple chemical reaction. CEZOHN reveals not only electrical, eletromechanical behavior but also photoelectrical behavior. This paper reports specially photo-response and sensitivity of CEZOHN under several light source: UV light, sun and fluorescent light. The fabrication process is briefly introduced, and induced voltage, induced current under light source are investigated. Also, the ZnO effect of CEZOHN and its mechanism is studied and its possibility of application as photosensor, photodiode, photovoltaic device will be discussed.

With smart materials and adaptive structures being nudged into mainstream technology progressively, the smart composites are donning a predominant role as indispensable structures. Among these, the Ionic Polymer Metal Composites (IPMC), with their large bending deformation and relaxation characteristics at very low voltages are attractive as transducers in many areas of application. The actuation and sensing properties of IPMC have been sought after for various engineering functions. The paper focuses on combining the ionic polymer with multi-walled carbon nanotube Bucky paper electrodes to create an enhanced IPMC, and comparatively analyzes the different methodologies briefly discussing the electrode morphology and also compares the uniformity of the electrode plating obtained from the different processes. This paper also concentrates on making use of different ionic solutions for comparison such as to determine the most suited ion content within the solid electrolyte for effective IPMC actuation. This new functionally graded material is tested for its bending deformation, blocking force and the current consumption to prove the electromechanical efficiency of the Bucky paper IPMC. By studying the electromechanical properties of this smart composite actuator based on its actuation under different electric excitations, we can draw conclusions subsequently from the results of the comparison.

The appearance of translucent materials is strongly affected by bulk (or sub surface) scattering. For paper and carton board, lateral light propagation and angle-resolved reflection have been studied extensively but treated separately. The present work aims at modelling the BSSRDF of turbid media in order to study the angular variation of the reflectance as function of the lateral propagation within the medium. Monte Carlo simulations of the spatial- and angle resolved reflectance of turbid media are performed for different scattering and absorption coefficients, phase functions and surface topographies representative for uncoated paper grades. The angle-resolved radiance factor of turbid media is found to be function of the lateral light propagation within the substrate and both the reflected radiance factor and the fluorescence emission are found to be clearly non- Lambertian, although the latter clearly depends on the light absorption at the excitation wavelength. It is also suggested that the modelling of uncoated paper should not include surface scattering. The findings impact on the appearance of turbid media at different angles and make measurements of the lateral light propagation dependent on the instrument geometry.

This study involves measurements of pulp consistency in cuvette and by an online apparatus, by innovatively scattering photoacoustic (SPA) method. The theoretical aspects were described at first. Then, a few kinds of wood fiber suspensions with consistencies from 0.5% to 5% were studied in cuvette. After that, a pilot of online apparatus was built to measure suspensions with fiber consistency lower than 1% and filler content up to 3%. The results showed that although there were many fiber flocks in cuvette which strongly affected the measurement accuracy of samples consistencies, the apparatus can sense fiber types with different optical and acoustic properties. The measurement accuracy can be greatly improved in the online style apparatus, by pumping suspension fluids in a circulating system to improve the suspension homogeneity. The results demonstrated that wood fibers cause larger attenuation of acoustic waves but fillers do not. On the other hand, fillers cause stronger scattering of incident light. Therefore, our SPA apparatus has a potential ability to simultaneously determine fiber and filler fractions in pulp suspensions with consistency up to 5%.

This paper studies the correlation between the time-of-flight (TOF) of laser pulses and paper density, basis weight, thickness and the beating of pulp. Paper samples made from unbeaten and beaten pulp were compressed from 500kg/m3 to 1100kg/m3 and laser pulses were shot through them during pressing. Changes were observed in the thickness of the samples and in the TOF of the laser pulses. The results show that TOF decreases during comrpession. This indicates that distances between the various scattering surfaces decrease. This phenomenon becomes more pronounced as the basis weight increases. The beating of the pulp before papermaking increases the number of scattering surfaces, thus broadening the laser pulse and causing delay. These two effects cannot be separated with the equipment used. Papers made from different pulp types each have unique delay constants.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A multilayer Paper Analytical Device (PAD) is provided for detection of at least two chemical components indicative of a low quality pharmaceutical or dietary supplement product. A method for detection of at least two chemical components indicative of a low quality pharmaceutical or dietary supplement product is also provided that employs a multilayer PAD. A kit is provided for detection of at least two chemical components indicative of a low quality pharmaceutical or dietary supplement product that includes a multilayer PAD and instructions for using the kit.

Plastic passive matrix (PM) and active matrix (AM) electronic paper displays (EPDs) have been prepared by SiPix's Microcup® roll-to-roll manufacturing processes using ITO/PET films. The Microcup® displays have shown outstanding environmental stability and excellent physico-mechanical properties such as scratch, impact and flexure resistances even in high temperature and humidity conditions. A PMEPD recently prepared on inexpensive row-and-column patterned ITO/PET films has shown a contrast ratio of >10, ta n 15 V. More than 8 levels of grayscale with outstanding bistability have been demonstrated by either pulse width or pulse count modulation. No noticeable degradation of the mid-tone images has been observed even after the power was turned off for more than 5 days. Moreover, the electro-optical responses, particularly the threshold voltage and gamma of the PMEPDs remain essentially the same within a wide range (20-60°C) of operation temperature.

Many paper mills use ultrasonic techniques to measure the Tensile Stiffness Index, TSI, of the paper sheet. They then assume that the TSI value is the same as the fibre orientation anisotropy. This is true if the paper is allowed to dry without any internal tension or elongation, but does not apply to paper manufactured in a paper machine. The paper machine introduces tension and elongation as soon as the fibre is placed on the forming fabric. These factors increase through the press section and are accentuated in the drying section. In order to uniquely measure the fibre orientation anisotropy on the surfaces, the proposed method uses replicas of both paper surfaces to produce a laser diffraction pattern. The obtained pattern reveals an elliptical shape, which is related to the fibre orientation anisotropy of the paper surface. By measuring the ellipticity of the diffraction pattern and the deviation with respect to the machine direction, one can quantify the fibre orientation distribution. Different papers from the bench market have been successfully tested with the developed system. This article describes the new developed optical system and its innovative capabilities in the field to produce maps of the fibre orientation of a complete paper sheet surface. A selection of the obtained results to prove its feasibility is also presented.

In the production of pigment-coated paper or paperboard, the method and rate of drying of the coating will significantly influence the print quality of the finished product. Improper drying during initial st sages can cause binder migration that leads to its non-uniform concentration on the surface of the coating. Such effect causes print mottle, and is a primary reason for poor print quality. The location at which binder immobilization has occurred is called the Gel Point. An on-line fiber optic sensor system has been applied to continuously monitor the location of the Gel Point. Each sensor consists of a light source, an optical fiber for delivering the radiation, two optical fibers for diffuse and specular radiation monitoring and two detectors. The ratio R between diffuse and specular signals indicates coating conditions. A system description and experimental results are presented. The Gel Point measurement system has show that is provides a sensitive measurement of the gel point location, as it is affected by machine speed, coat weight, incoming substrate moisture levels and drying energy and can predict print mottle. This provides the paper maker with a completely independent method for monitoring the coating drying process.

Surface enhanced Raman spectroscopy (SERS) is a highly sensitive sensing technique, offering sensitivity comparable to that of fluorescence while providing structure-dependent analyte information. In recent years, we have developed an innovative optofluidic SERS substrate by inkjet printing metal nanoparticles onto paper. By virtue of generating a SERS substrate on cellulose, we gain a flexible SERS sensing device, as well as the ability to harness the intrinsic wicking properties of paper to enable both separation and concentration of analytes. Here we demonstrate the application of paper-chromatographic separation to allow on-substrate separation, concentration and discrimination. By using inexpensive single-labeled DNA probes in a typical PCR amplification, we obtain a mixture containing whole probes (negative result) and probes which have been hydrolyzed by the Taq polymerase (positive result). Leveraging the solubility differences between the whole and hydrolyzed probes and the cellulose separation matrix, we are able to perform a multiplexed interrogation of the targets. Notably, this does not require the use of dual labeled DNA probes (expensive) or multiple excitation sources and filter sets needed for a multiplexed fluorescence measurement (expensive and bulky). All SERS measurements are performed using a portable spectrometer and diode laser; in combination with a portable low-power DNA amplification system, this technique has the potential to be used for rapid on-site multiplexed genetic detection, without requiring complex optical equipment.

In the recent times, cellulose-based Electro-Active Paper (EAPap) has been investigated to have electro-mechanical coupling and piezoelectric effects which are promising characteristics for a smart material. In this paper, the effects of electrodes of EAPap are investigated for vibration energy harvesting. Although piezopolymers have smaller value of electro-mechanical coupling constants as compared to the piezoceramics, but are very flexible, which motivates to use these materials as potential media for flexible energy harvesting. Cellulose based Electro-active papers are deposited with different metal electrodes like aluminum, gold and silver. The fabricated samples are tested with aluminum cantilever beam under an input excitation. The effects of area of electrodes are also investigated by comparing the output voltage at the different area of electrodes ranging from 400mm2 to 1200mm2. EAPap cantilever are tested at lowest resonant frequency and under varying acceleration amplitude to maximize the output voltage. From the experimental results, it is concluded that the potential of EAPap as a flexible energy harvester are very promising.

Many infectious diseases, as well as some cancers, that affect global health are most accurately diagnosed through nucleic acid amplification and detection. There is a great need to simplify nucleic acid-based assay systems for use in global health in low-resource settings as well as in settings that do not have convenient access to laboratory staff and equipment such as doctors’ offices and home care settings. In developing countries, unreliable electric power, inadequate supply chains, and lack of maintenance for complex diagnostic instruments are all common infrastructure shortfalls. Many elements of instrument-free, disposable, nucleic acid amplification assays have been demonstrated in recent years. However, the problem of instrument-free,1 low-cost, temperature-controlled chemical heating remains unsolved. In this paper we present the current status and results of work towards developing disposable, low-cost, temperature-controlled heaters designed to support isothermal nucleic acid amplification assays that are integrated with a two-dimensional paper network. Our approach utilizes the heat generated through exothermic chemical reactions and controls the heat through use of engineered phase change materials to enable sustained temperatures required for nucleic acid amplification. By selecting appropriate exothermic and phase change materials, temperatures can be controlled over a wide range, suitable for various isothermal amplification methods, and maintained for over an hour at an accuracy of +/- 1°C.

In the present work a non-invasive technological study on three molds from Magnani’s mills in Pescia (Pistoia, Italy) was carried out. The three molds investigated have been those for making: 1) the invitation letters to the marriage between Napoleon and Maria Luisa of Austria in 1810; 2) the paper sheets used by Pablo Picasso in 1917 for the drawings of the Russian Ballets currently preserved in the Picasso Museum in Paris; 3) the holy manuscript Bhagavata Purana realized in India in 1840 and currently preserved in the “Museum of Art” of San Diego. The chemical composition of the metal alloy components were investigated and compared using Laser Induced Plasma Spectroscopy (LIPS), electron microscopy (ESEM-EDX) and Ion Beam Analysis (IBA) while shape and size comparisons were carried out by means of a homemade 3D digital microscopy device. Metallographic characterizations were also carried out on some very small samples. This allowed pointing out the different crafting features of the three molds. The results achieved and represent the first step towards an overall characterization, which will be carried out on Magnani’s mold collections.

Semiconducting ZnO layer chemically grown on regenerated cellulose and its flexible paper transistor were studied. ZnO layer-cellulose composite was prepared by a simple chemical reaction process which included alkaline hydrolysis at low temperature lower than 100 °C and used wet regenerated cellulose as a hydrophilic substrate. By increasing the concentration of ZnO seeding layer on cellulose, the area of ZnO cluster also increases. In the low concentration conditions from 20 mM to 50 mM, it is observed that the average size of ZnO nanorods increases as the seeding concentration increases. However, flower-shaped ZnO structure is observed in higher concentration over 50 mM due to clustering effect during the growth of ZnO rods. Thin ZnO layer composed of nano-rods seemed to be grown well on regenerated cellulose and layer thickness of ZnO was well controlled by reaction time. Structural data of as grown ZnO/cellulose provides the crystal orientation-limited growth mechanism of ZnO nano-rod, which can be controlled by the reaction time of chemical process. Using conventional lift-off process, thin ZnO layer based transistor was fabricated by forming source/drain as well as gate electrode. More detailed ZnO-cellulose based transistor is discussed.

We report a novel surface enhanced Raman Scattering (SERS) substrate platform based on a common filter paper adsorbed with plasmonic nanostructures. Paper based SERS substrate overcomes many of the challenges associated with conventional SERS substrates based on rigid substrates such as silicon and glass. The paper-based design results in a substrate that combines all of the advantages of conventional rigid and planar SERS substrates in a dynamic flexible scaffolding format. We discuss the fabrication, physical characterization and SERS activity of our novel substrates using non-resonant analytes.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

This paper presents the influence of reaction time for the thickness and particle density of ZnO layer. Paper-like ZnOCellulose hybrid nanocomposite was fabricated using a low temperature hydrothermal synthesis in the aqueous solution. This ZnO nanostructure on the cellulose as thin ZnO layer, utilized substrate via simple reaction including the alkaline hydrolysis, was composed by hydrothermal synthesis. It is revealed that growth mechanism of ZnO nano-rod of the ZnO-Cellulose hybrid nanocomposite is governed as the crystal orientation limited by structural and morphological analysis. As the reaction time of chemical process increases, the size of the ZnO nanostructure also increases. These composite materials can be used to smart materials for flexible electronic or electro-mechanical devices such as transistors and strain sensors.

This paper investigates a direct inkjet printing method for electrode patterning on cellulose Electro-Active Paper (EAPap). Flexibility and transparency of the EAPap are advantageous for a versatile substrate in flexible printable electronics. The effects of curing conditions are evaluated by electrical resistivity and morphological analysis. To fabricate EAPap device, inter-digital transducer (IDT) electrodes are printed on the EAPap with drop-on-demand inkjet printing method. Silver patterns are obtained from organometallic silver ink by jetting and heat treatment at 160°C in air. IDT patterns are made on cellulose for variety and extensive application of inkjet printing electronics.

The possibility as a vibration sensor of Electro-Active paper (EAPap) based on piezoelectricity was investigated in the present paper. The EAPap was fabricated by regenerating and tape casting cellulose. The gold, silver and aluminum were deposited on both sides of the cut cellulose film using a thermal evaporator. The sample was coated by thin laminating film for packaging. The simple aluminum cantilevered beam was used for the vibration testing and EAPap was attached on the beam. The original EAPap sensor without grounding and shielding has greatly affected by the surrounding noise such as power noise especially. The power noise reduced dramatically with grounding and shielding of EAPap. The impulsive response of EAPap provided correct dynamic characteristics of the beam. Forced response of EAPap presented that gold and silver electrodes are suitable for EAPap sensor but aluminum electrode provides too many noise due to high resistance. PVDF provided similar characteristics of EAPap, which results EAPap has high potential as a vibration sensor.

As a bio/chemical sensing technique, surface enhanced Raman spectroscopy (SERS) offers sensitivity comparable to that of fluorescence detection while providing highly specific information about the analyte. Although single molecule identification with SERS was demonstrated over a decade ago, today a need exists to develop practical solutions for point-of-sample and point-of-care SERS systems. In recent years, optofluidic SERS has emerged, in which microfluidic functions are integrated to improve the performance of SERS. Advancements in optofluidic SERS are leading towards portable analytical systems, but the devices are currently too expensive and too cumbersome for limited resource settings. Recently, we demonstrated the fabrication of SERS substrates by inkjet printing silver nanostructures onto paper. Using a low-cost commercial inkjet printer, we chemically patterned cellulose paper to form hydrophobic regions, which can control the aqueous sample on the paper microsystem. Additionally, we inkjet-printed silver nanoparticles with micro-scale precision to form SERS-active biosensors. Using these devices, we have been able to achieve detection limits comparable to conventional nanofabricated substrates. Furthermore, we leverage the fluidic properties to enhance the performance of the SERS devices while also enabling unprecedented ease of use. Paper dipsticks concentrate a relatively large sample volume into a small SERS-active detection region at the tip. Likewise, paper swabs collect samples from a large surface area and concentrate the collected molecules into a SERS sensor on the paper. We will summarize the progress in the fabrication and use of these paper-based optofluidic devices, and will describe their use in practical applications for point-of-sample detection.

Paper makers use many different synthetic and natural chemical additives for a variety of different reasons during the wet formation process. They are used to influence the efficiency of the formation process or to impart specific sheet properties. They are usually added (with the exception of pigments) at a level of around 0-5% by weight of the other components of the furnish and, because of their relatively high cost, they often represent a significant proportion of the total raw material costs - particularly for recycled grades where the fibre costs may be very low. When it is necessary to modify bulk sheet properties, as in the control of aqueous fluid penetration (internal sizing), the chemicals have to be added to the wet fibre suspension so that they become well distributed throughout the z-direction of the sheet. Chemicals which are added as a surface treatment to the dry sheet are usually only able to influence surface properties.

The composition of photographic color negative papers is reviewed. Information is presented on the potential detrimental effect of the polyethylene resin-coated (RC) paper support on the thermal stability of the silver halide element. Evidence is provided for the major role that the pH of the dry paper stock has in this effect. A mechanism for the detrimental photographic performance involving both the RC and the paper stock is proposed.

From the chemical point of view paper coatings are mainly polymer dispersions. Polymer dispersions are constituted in multitude fields, for example as dispersion coatings or adhesives. As far as no additional treatment is done, polymer materials as well as polymer agents contain non polymer, volatile organic components that may arise from: (1) incomplete polymerization of the applied monomers, (2) primary materials containing non polymerizable components, (3) undesirable side reactions during the synthesis. Requirements for the removal of volatile substances from polymer dispersion are given by several reasons: (1) low molecular substances deteriorate the product characteristics (viscosity, thermal stability and others), (2) in order to comply with legislative standards, volatile organic compounds have to be removed from dispersions, especially when applied to large surfaces (e.g. in surface refining in paper and leather industries as well as on coating). The removal of volatile organic compounds (deodorization) can be realized in continuous or discontinuous processes. In contrast to highly developed process technology, the process itself is not well understood, especially mass transport phenomena between the gas phase and the aqueous polymer dispersion are insufficiently and controversially discussed in the literature. Two processes, their advantages and disadvantages and the description by mathematical- mechanistic models are presented in this paper.

Uncontrolled growth of bacteria and fungi in the papermaking process adversely affects machine runability. How this growth influences factors in the finished sheet and sheet print properties is often overlooked, even though it can have a profound effect on printing characteristics. Many of the materials used in making paper coatings are excellent microbial nutrients. In addition to being nutrients, these compounds are critical to performance. For example, coatings made of poorly preserved clays can form a surface that has fine scratches caused by microagglomeration of the clay particles. This may be caused by microbial degradation of the dispersants in the clays. This paper explores these issues and discusses steps that can be taken to minimize these problems.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

This paper reports a remotely-driven electro-active paper (EAPap) actuator by modulated microwaves. So far we have demonstrated a remotely driven EAPap actuator by means of rectenna and control circuit. The rectenna consists of dipole antenna and rectifying circuit, which converts microwave to dc power. Once microwaves are incident on the dipole rectenna, it converts microwaves into a dc power and the control circuit feeds the power to the EAPap actuator by alternating it so as to produce a bending motion of the EAPap actuator. However, due to the power consumption of the control circuit, the remotely-driven actuator system requires more dc power to activate the control circuit. Thus, we propose a remotely-driven EAPap actuator that does not require the control circuit. Instead of the control circuit, microwaves are modulated with the control signal, and by rectifying the modulated microwaves with the rectenna, the control signal can be regenerated for activating the EAPap actuator. Detailed modulated microwave, rectenna design, fabrication, characterization and the actuation of rectenna-EAPap by modulated microwave are explained.