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We present an ultra-high frequency radio frequency identification based wireless communication set-up for paper-based point-of-care diagnostic applications, based on a sensing radio frequency identification chip. Paper provides a low-cost, disposable platform for ease of fluidic handling without bulky instrumentation, and is thus ideally suited for point-ofcare applications; however, result communication – a crucial aspect for healthcare to be implemented effectively – is still lacking. Printing of radio frequency identification antennas and electronic circuitry for sensing on paper are presented, with read out of the results using a radio frequency identification reader illustrated, demonstrating the feasibility of developing integrated, all-printed solutions for point-of-care diagnosis in resource-limited settings.

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.

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, please 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 present an industrial application of multispectral imaging, for density measurement of colorants in photographic paper. We designed and developed a 9-band LED illumination based multispectral imaging system specifically for this application in collaboration with FUJIFILM Manufacturing Europe B.V., Tilburg, Netherlands. Unlike a densitometer, which is a spot density measurement device, the proposed system enables fast density measurement in a large area of a photo paper. Densities of the four colorants (CMYK) at every surface point in an image are calculated from the spectral reflectance image. Fast density measurements facilitate automatic monitoring of density changes (which is proportional to thickness changes), which helps control the manufacturing process for quality and consistent output. Experimental results confirm the effectiveness of the proposed system.

In this paper, we demonstrate an automatic image analysis for Micro Total Analysis Systems (μTAS) or Lab-on-Paper (LoP). By placing fiducial markers on μTAS, application can crop image and remove bending distortions, also it can perform colorimetric analysis. With previously taken photo of μTAS device with applied reagents, user can determine ie. illness presence by uploading photo into the program. In the paper was prepared μTAS sheet, algorithm for finding fiducial points and software for colorimetric analysis written in Matlab.

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.

Electrophoretic display (EPD) has been widely used in e-paper applications because of its flexibility, low power consumption, good sunlight visibility. The commercial success of monochromic EPD has boosted the development of full- color EPD to further satisfy people’s demand for various applications. However, many challenges shall be overcome before commercializing it. In this paper, we will introduce the EPD’s fundamental operation, the design of driving waveform for optimizing the opto-electronic performance, and the strategies for achieving full-color EPD as well as a color EPD prototype fabricated by transfer method.

Research on affordable point-of-care health diagnostics is rapidly advancing1. Colorimetric biosensor applications are typically qualitative, but recently the focus has been shifted to quantitative measurements2,3. Although numerous qualitative point-of-care (POC) health diagnostic devices are available, the challenge exists of developing a quantitative colorimetric array reader system that complies with the ASSURED (Affordable, Sensitive, Specific, User-friendly, Rapid and Robust, Equipment-free, Deliverable to end-users) principles of the World Health Organization4. This paper presents a battery powered 8-bit tonal resolution colorimetric sensor circuit for paper microfluidic assays using low cost photo-detection circuitry and a low-power LED light source. A colorimetric 3×3-pixel array reader was developed for rural environments where resources and personnel are limited. The device sports an ultralow-power E-ink paper display. The colorimetric device includes integrated GPS functionality and EEPROM memory to log measurements with geo-tags for possible analysis of regional trends. The device competes with colour intensity measurement techniques using smartphone cameras, but proves to be a cheaper solution, compensating for the typical performance variations between cameras of different brands of smartphones. Inexpensive methods for quantifying bacterial assays have been shown using desktop scanners, which are not portable, and cameras, which suffer severely from changes in ambient light in different environments. Promising colorimetric detection results have been demonstrated using devices such as video cameras5, digital colour analysers6, flatbed scanners7 or custom portable readers8. The major drawback of most of these methods is the need for specialized instrumentation and for image analysis on a computer.

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.

Given monochromatic infrared LED (light emitting diode) device best modulation current, frequency, distance to reach its maximum output power and improve the measuring accuracy of quantifier. Design a wavelength of 2.12 μm, 1.89 μm monochromatic infrared emissions and detection optical path, two monochromatic infrared lights which the photo source sends out after transmits the analyte across the same point to achieve the same point detection and improve the accuracy of the measurement. After the paper samples basis weight have carried out nondestructive testing, which was improved from the aspects of structure. By using the light source, halogen tungsten lamp, filter wheel, electrical equipment can be saved, and it can simplify the measuring system. The experimental results show that when measuring the thickness of the paper in the range, the relative error is within 1%.

This paper will review the origins and state of the art in paper-based electronics, suggesting the stage is set for future promising applications. Current interest in paper-based electronics can trace its roots to recent developments in paper-based microfluidics. With a need to improve the reliability and sensitivity of paperbased microfluidics for certain tasks, there were natural efforts to begin embedding sensing electrodes into microfluidic devices. Recognizing the general benefits of paper as an advanced material (e.g., its environmental friendliness, bendable nature, and low cost), efforts in paper-based electronics also began to take a life of their own with demonstrations of transistors, batteries and devices for energy storage, energy harvesting, sensors to improve situational awareness, acoustics, and displays. The state-of-the-art paper-based electronic devices have benefited and will continue to profit from technologies for printing and transferring electronic functionality onto the surfaces of paper-based substrates. Nonetheless, the authors suggest that many future promising applications will go beyond using paper as a carrier/substrate for electronic components to explore tuning of the electrical, mechanical, and chemical properties of the paper itself. With these technical advances, paper-based electronics will move closer to economically viable killer applications.

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.

The UK National Quantum Technology Hub in Sensors and Metrology is one of four flagship initiatives in the UK National of Quantum Technology Program. As part of a 20-year vision it translates laboratory demonstrations to deployable practical devices, with game-changing miniaturized components and prototypes that transform the state-of-the-art for quantum sensors and metrology. It brings together experts from the Universities of Birmingham, Glasgow, Nottingham, Southampton, Strathclyde and Sussex, NPL and currently links to over 15 leading international academic institutions and over 70 companies to build the supply chains and routes to market needed to bring 10–1000x improvements in sensing applications. It seeks, and is open to, additional partners for new application development and creates a point of easy open access to the facilities and supply chains that it stimulates or nurtures.

A fiber optic Bragg grating (FBG) sensor and interrogation scheme has been designed to capture the momentary peak pressure forces in the nip of two adjacent paper machine rolls. The spatial distribution of these nip forces along circumference and length of the roll, for production speeds of up to 2000 m/min are investigated. Additionally, this FBG sensor system measures the temperature distribution in the roll cover. FBG sensor embedding has been optimized for the implementation of pressure force measurements in various roll cover materials. High strength draw tower grating (DTG) sensor arrays were used for the embedding process combined with spectrometric interrogation and autonomous power supply technologies. This results in an extremely robust fiber optic sensor system for operation at rotation speeds of 700 rpm, equivalent to centrifugal accelerations of 300 G. These measurements enable immediate quality control during various stages of the high-speed paper production process. © (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

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.

There are several paradigms for color generation in reflective displays (e-Paper) including RGBW color filtering or stacked RGB or CMY. Theoretically, the highest white state reflectance and best color gamut are achieved by stacking three layers of pixels. However, stacking 3 layers induces significant optical losses especially at high resolution and typically does not allow for video operation. Therefore RGBW color filtering is currently preferred for higher resolution and single-layer e-Paper, but only provides color at 25% of the area and a maximum theoretical white reflectance of 50%. Presented herein is a new bi-primary color-system that cooperatively displays two complimentary colors inside a single sub-pixel, and therefore doubles the white state reflectance and color gamut for single-layer e-Paper. Also discussed are candidate e-Paper technologies that may be able to adopt the bi-primary color system, including possible advantages and challenges for each technology.

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.

By combining the physical principles behind the nastic plant movements and the rich designs of paper folding art, we propose a new class of multi-functional adaptive structure called fluidic origami cellular structure. The basic elements of this structure are fluid filled origami "cells", made by connecting two compatible Miura-Ori stripes along their crease lines. These cells are assembled seamlessly into a three dimensional topology, and their internal fluid pressure or volume are strategically controlled just like in plants for nastic movements. Because of the unique geometry of the Miura-Ori, the relationships among origami folding, internal fluid properties, and the crease bending are intricate and highly nonlinear. Fluidic origami can exploit such relationships to provide multiple adaptive functions concurrently and effectively. For example, it can achieve actuation or morphing by actively changing the internal fluid volume, and stillness tuning by constraining the fluid volume. Fluidic origami can also be bistable because of the nonlinear correlation between folding and crease material bending, and such bistable character can be altered significantly by fluid pressurization. These functions are natural and essential companions with respect to each other, so that fluidic origami can holistically exhibit many attractive characteristics of plants and deliver rapid and efficient actuation/morphing while maintaining a high structural stillness. The purpose of this paper is to introduce the design and working principles of the fluidic origami, as well as to explore and demonstrate its performance potential.

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.

In order to consummate the management of bank paper, a new algorithm which can recognize the areas of paper tape in bundle of paper money is presented. Image segmentation is used to divide the image into several sub-blocks. Specifically, image entropy is computed in each sub-block. Experimental in different algorithms, including color training algorithm and the median filter and edge detection algorithm, demonstrates its real-time, effectiveness and robustness.

For the last eight years, the solar industry has experienced annual growth of over 40%. Concerns over the rising costs of conventional energy, as well as its environmentally damaging effects, have been driving this vigorous investment in solar energy. Now, with grid parity almost upon us, the solar industry is reassessing what it will look like as a commoditized, mainstream power source. Do the best opportunities for solar lie with a centralized or decentralized model of production? What are the most bankable PV technologies? How can costs be cut and efficiencies improved to take things to the next level and make that last push to reach grid parity? In this paper, we will examine Solaria's LCPV technology and approach to the future of solar power.

International audience; Dirty Paper Trellis Codes (DPTC) watermarking, published in 2004, is a very efficient high rate scheme. Nevertheless, it has two strong drawbacks: its security weakness and its CPU computation complexity. We propose an embedding space at least as secure and a faster embedding. The embedding space is built on the projections of some wavelet coefficients onto secret carriers. It keeps a good security level and has also good psycho-visual properties. The embedding is based on a dichotomous rotation in the Cox, Miller and Boom Plane. It gives better performances than previous fast embedding approaches. Four different attacks are performed and revealed good robustness and rapidity performances.

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.

In present work the capabilities of an optical coherence tomography (OCT) setup to visualize paper structure are analyzed by means of Monte Carlo-simulation of the OCT images. The OCT setup at 910 nm was considered. Efficiency of several different optical clearing agents (OCA) for increasing the quality of the obtained images was studied. A multilayer non-planar edged paper model was developed for the characterization of a paper sample and simple recovery of its parameters. The effect of the setup parameters on the obtained OCT-images was studied. It was shown by comparison with the experimental data that the developed model provides satisfactory resemblance of simulated and experimental images of papers sample structure.

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.

The proliferation of digital information is leading to a wide range of applications which make it desirable to display data easily in many locations, all changeable and updateable. The difficulty in achieving such ubiquitous displays is the cost of signage, the cost of installation, and the software and systems to control the information being sent to each of these signs. In this paper we will talk about a networked system of such signs which are made from gyricon electronic paper. Gyricon electronic paper is a reflective, bistable display which can be made in large web sheets at a reasonable price. Since it does not require a backlight nor does it require power to refresh the display image, such technology is ideal for making signs which can be run on batteries with extremely long battery life, often not needing replacement for years. The display also has a very broad illumination scattering profile which makes it readily viewable from any angle. The basic operating mechanism of the display, its manufacturing technique, and achieved performance will be described, along with the description of a networked solution using many such signs controlled with system software to identify speakers and meetings in conference rooms, hospitality suites, or classrooms in universities. Systems will also be shown which are adapted to retail pricing signage and others which can be used for large format outdoor billboards.

The paper presents benefits of optical time-of-flight spectroscopy for the pulp and paper characterization. A semiconductor pulse laser and a streak camera as the photodetector were utilized in experimental part of research described in this paper. Distribution of the time of flight of photons through various kinds of wood pulp (e.g. pulp after mechanical treatment coming both fi-om tree species giving hard and soft wood and pulp after thermo-mechanical treatment) was measured. The pulp samples used in the measurements had consistency ranging from 0 to 5% of dry mass in the suspension. The influence of additives (kaolin, talc and calcium carbonate) present in the suspension on the time of flight distribution of photons was studied as well. Finally, dependence of the time of flight of photons through various kinds of the paper (i.e. newspaper, copy paper, and tissue) on the thickness of the sample was investigated.

We present an image data-hiding scheme based on near-capacity dirty-paper codes. The scheme achieves high embedding rates by "hiding" information into mid-frequency DCT coefficients among each DCT block of the host image. To reduce the perceptual distortion due to data-hiding, the mid-frequency DCT coefficients are first perceptually scaled according to Watson's model. Then a rate-1/3 projection matrix in conjunction with a rate-1/5 capacity-approaching dirty-paper code is applied. We are able to embed 1500 information bits into 256×256 images, outperforming, under a Gaussian noise attack, currently the best known data-hiding scheme by 33%. Robustness tests against different attacks, such as low-pass filtering, image scaling, and lossy compression, show that our scheme is a good candidate for high-rate image data-hiding applications.

The refractive index of paper was determined by measuring the propagation delay of photons in optically cleared paper boards. The determination was based on the assumption that photon propagation delay achieves minimum value as the paper is optimally cleared. The measured paper sheets was made from elemental chlorine-free market pulp, i.e. fully bleached, unbeaten, softwood kraft pulp. Nine different clearing agents with a refraction index between 1.329 and 1.741 were eLuperimented with. According to the streakmem measurements, the refractive index of the test paper was 1.557.

Phenylketonuria is a genetic disease, which causes the metabolization disorder of phenylalanine, this disorder would damage the neural system of infants as a result of the accumulation of phenylalanine in blood. Therefore, it is of great importance to diagnose and treat phenylketonuria as early as possible for newborns. The aim of this paper is to develop a fluorescence detection system to measure blood phenylalanine concentration of new-born infants. In this design, a high luminance ultraviolet LED is used for excitation source, and a kind of bifurcated optical fiber assembly is applied for conduction of light. The excitation source is filtered and coupled into quartz fibers of the bifurcated fiber assembly for conduction of light to excite the fluorescence of phenylalanine in blood sample. The collected fluorescence is transmitted along the glass fibers of the assemblies and coupled to a photomultiplier tube. The fluorescence is filtered with 470~500 nm band-pass filter to subdue scattered excitation light and to limit the spectral width of the detected fluorescence. By the comparison with a standard instrument, the new system with low power consumption, low cost and small size is also proven sensitive and accurate, which meets the demand of clinical phenylketonuria screening.

This paper considers the classic non-causal state information problem in channel coding where non-causal channel state knowledge at the transmitter, which is also called the Gel'fand Pinsker problem. This paper determines Lagrangian dual expression for this problem, illustrating that Costa's dirty paper coding result can be replicated using the dual-problem methodology.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

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.

Technological development is seen as one of the fundamental forces in shaping the modern economies. The effects and the role of technological development are also central questions in many issues of environmental protection. This paper presents the results of a life cycle assessment study of the Finnish pulp an paper industry. Three comparative scenarios are drawn. Two scenarios describe the technological levels and production volumes of 1993 and 1997. A comparison scenario with the production volumes of 1997 and the technological level of 1997 describes the effects avoided by improvements. The results demonstrate that technological development has had considerable effects on the material flows of the industry within a relatively short period of time. Changes in most material flows result from various improvements. The environmental performance of the industry has been improved by both changes in operative practices as well as capital investments. The study fails to describe some aspects of realized developments and thus indicates that factors connected to technological change are highly problematic for LCA modelling.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Food-borne pathogens such as Listeria monocytogenes have been recognized as a major cause of human infections worldwide, leading to substantial health problems. Food-borne pathogen identification needs to be simpler, cheaper and more reliable than the current traditional methods. Here, we have constructed a low-cost paper biosensor for the detection of viable pathogenic bacteria with the naked eye. In this study, an effective isothermal amplification method was used to amplify the hlyA mRNA gene, a specific RNA marker in Listeria monocytogenes . The amplification products were applied to the paper biosensor to perform a visual test, in which endpoint detection was performed using sandwich hybridization assays. When the RNA products migrated along the paper biosensor by capillary action, the gold nanoparticles accumulated at the designated Test line and Control line. Under optimized experimental conditions, as little as 0.5 pg/μL genomic RNA from Listeria monocytogenes could be detected. The whole assay process, including RNA extraction, amplification, and visualization, can be completed within several hours. The developed method is suitable for point-of-care applications to detect food-borne pathogens, as it can effectively overcome the false-positive results caused by amplifying nonviable Listeria monocytogenes.

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.