Organic light emitting board for dynamic interactive display

Interactive displays involve the interfacing of a stimuli-responsive sensor with a visual human-readable response. Here, we describe a polymeric electroluminescence-based stimuli-responsive display method that simultaneously detects external stimuli and visualizes the stimulant object. This organic light-emitting board is capable of both sensing and direct visualization of a variety of conductive information. Simultaneous sensing and visualization of the conductive substance is achieved when the conductive object is coupled with the light emissive material layer on application of alternating current. A variety of conductive materials can be detected regardless of their work functions, and thus information written by a conductive pen is clearly visualized, as is a human fingerprint with natural conductivity. Furthermore, we demonstrate that integration of the organic light-emitting board with a fluidic channel readily allows for dynamic monitoring of metallic liquid flow through the channel, which may be suitable for biological detection and imaging applications.

Electrical conductivity enhancement of epitaxially grown TiN thin films

Titanium nitride (TiN) presents superior electrical conductivity with mechanical and chemical stability and compatibility with the semiconductor fabrication process. Here, we fabricated epitaxial and polycrystalline TiN (111) thin films on MgO (111), sapphire (001), and mica substrates at 640oC and room temperature by using a DC sputtering, respectively. The epitaxial films show less amount of surface oxidation than the polycrystalline ones grown at room temperature. The epitaxial films show drastically reduced resistivity (~30 micro-ohm-cm), much smaller than the polycrystalline films. Temperature-dependent resistivity measurements show a nearly monotonic temperature slope down to low temperature. These results demonstrate that high temperature growth of TiN thin films leads to significant enhancement of electrical conductivity, promising for durable and scalable electrode applications.Comment: 14 pages, 3 figure

Chlorophyll Fluorescence Imaging for Environmental Stress Diagnosis in Crops

The field of plant phenotype is used to analyze the shape and physiological characteristics of crops in multiple dimensions. Imaging, using non-destructive optical characteristics of plants, analyzes growth characteristics through spectral data. Among these, fluorescence imaging technology is a method of evaluating the physiological characteristics of crops by inducing plant excitation using a specific light source. Through this, we investigate how fluorescence imaging responds sensitively to environmental stress in garlic and can provide important information on future stress management. In this study, near UV LED (405 nm) was used to induce the fluorescence phenomenon of garlic, and fluorescence images were obtained to classify and evaluate crops exposed to abiotic environmental stress. Physiological characteristics related to environmental stress were developed from fluorescence sample images using the Chlorophyll ratio method, and classification performance was evaluated by developing a classification model based on partial least squares discrimination analysis from the image spectrum for stress identification. The environmental stress classification performance identified from the Chlorophyll ratio was 14.9% in F673/F717, 25.6% in F685/F730, and 0.209% in F690/F735. The spectrum-developed PLS-DA showed classification accuracy of 39.6%, 56.2% and 70.7% in Smoothing, MSV, and SNV, respectively. Spectrum pretreatment-based PLS-DA showed higher discrimination performance than the existing image-based Chlorophyll ratio

Green Synthesis of Silver and Gold Nanoparticles via <i>Sargassum serratifolium</i> Extract for Catalytic Reduction of Organic Dyes

The green synthesis of inorganic nanoparticles (NPs) using bio-materials has attained enormous attention in recent years due to its simple, eco-friendly, low-cost and non-toxic nature. In this work, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized by the marine algae extract, Sargassum serratifolium (SS). The characteristic studies of bio-synthesized SS-AgNPs and SS-AuNPs were carried out by using ultraviolet–visible (UV–Vis) absorption spectroscopy, dynamic light scattering (DLS), high-resolution transmission electron microscope (HR-TEM), selected area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Phytochemicals in the algae extract, such as meroterpenoids, acted as a capping agent for the NPs’ growth. The synthesized Ag and Au NPs were found to have important catalytic activity for the degradation of organic dyes, including methylene blue, rhodamine B and methyl orange. The reduction of dyes by SS-AgNPs and -AuNPs followed the pseudo-first order kinetics

Integrated Navigation System Design for Micro Planetary Rovers: Comparison of Absolute Heading Estimation Algorithms and Nonlinear Filtering

This paper provides algorithms to fuse relative and absolute microelectromechanical systems (MEMS) navigation sensors, suitable for micro planetary rovers, to provide a more accurate estimation of navigation information, specifically, attitude and position. Planetary rovers have extremely slow speed (~1 cm/s) and lack conventional navigation sensors/systems, hence the general methods of terrestrial navigation may not be applicable to these applications. While relative attitude and position can be tracked in a way similar to those for ground robots, absolute navigation information is hard to achieve on a remote celestial body, like Moon or Mars, in contrast to terrestrial applications. In this study, two absolute attitude estimation algorithms were developed and compared for accuracy and robustness. The estimated absolute attitude was fused with the relative attitude sensors in a framework of nonlinear filters. The nonlinear Extended Kalman filter (EKF) and Unscented Kalman filter (UKF) were compared in pursuit of better accuracy and reliability in this nonlinear estimation problem, using only on-board low cost MEMS sensors. Experimental results confirmed the viability of the proposed algorithms and the sensor suite, for low cost and low weight micro planetary rovers. It is demonstrated that integrating the relative and absolute navigation MEMS sensors reduces the navigation errors to the desired level

A Comparative Study on Physicochemical, Photocatalytic, and Biological Properties of Silver Nanoparticles Formed Using Extracts of Different Parts of Cudrania tricuspidata

Green-synthesized silver nanoparticles (SNPs) have great potential for biomedical applications, due to their distinctive optical, chemical, and catalytic properties. In this study, we aimed to develop green-synthesized SNPs from extracts of Cudrania tricuspidata (CT) roots (CTR), stems (CTS), leaves (CTL), and fruit (CTF) and to evaluate their physicochemical, photocatalytic, and biological properties. CTR, CTS, CTL, and CTF extracts were evaluated and compared for their total phenol and flavonoid content, reducing capacity, and antioxidant activity. The results revealed that CTR, CTS, CTL, and CTF extracts have high phenol and flavonoid content, as well as a powerful antioxidant and reducing capacity. CTR and CTS extracts showed the strongest effects. The results from UV-Vis spectra analysis, dynamic light scattering, high-resolution transmission electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy showed the successful formation of CT-SNPs with surface morphology, crystallinity, reduction capacity, capsulation, and stabilization. Synthesized CT-SNPs successfully photocatalyzed methylene blue, methyl orange, rhodamine B, and Reactive Black 5 within 20 min. The CTR- and CTS-SNPs showed better antibacterial properties against different pathogenic microbes (Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Salmonella enteritidis) than the CTL- and CTF-SNPs. CTS- and CTR-SNPs showed the most effective cytotoxicity and antiapoptosis properties in human hepatocellular carcinoma cells (HepG2 and SK-Hep-1). CT-SNPs also seemed to be more biologically active than the CT extracts. The results of this study provide evidence of the establishment of CT extract SNPs and their physicochemical, photocatalytic, and biological properties

Epitaxially Grown Ferroelectric PVDF&amp;#8208;TrFE Film on Shape&amp;#8208;Tailored Semiconducting Rubrene Single Crystal

Epitaxial crystallization of thin poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) films is important for the full utilization of their ferroelectric properties. Epitaxy can offer a route for maximizing the degree of crystallinity with the effective orientation of the crystals with respect to the electric field. Despite various approaches for the epitaxial control of the crystalline structure of PVDF-TrFE, its epitaxy on a semiconductor is yet to be accomplished. Herein, the epitaxial growth of PVDF-TrFE crystals on a single-crystalline organic semiconductor rubrene grown via physical vapor deposition is presented. The epitaxy results in polymer crystals globally ordered with specific crystal orientations dictated by the epitaxial relation between the polymer and rubrene crystal. The lattice matching between the c-axis of PVDF-TrFE crystals and the (210) plane of orthorhombic rubrene crystals develops two degenerate crystal orientations of the PVDF-TrFE crystalline lamellae aligned nearly perpendicular to each other. Thin PVDF-TrFE films with epitaxially grown crystals are incorporated into metal/ferroelectric polymer/metal and metal/ferroelectric polymer/semiconductor/metal capacitors, which exhibit excellent nonvolatile polarization and capacitance behavior, respectively. Furthermore, combined with a printing technique for micropatterning rubrene single crystals, the epitaxy of a PVDF-TrFE film is formed selectively on the patterned rubrene with characteristic epitaxial crystal orientation over a large area

Self-assembled Interconnection by Bamboo-like Carbon Nanotubes

Carbon nanotubes (CNTs) could be formed on Si substrate using nickel catalyst under microwave plasma-enhanced chemical vapor deposition system. Under the high, negative-bias voltage (−400 V) condition, we found the formation of the carbon nanotube islands and the bamboo-like carbon nanotube interconnection lines. Most of the bamboo-like carbon nanotubes connected with the carbon nanotubes themselves, which indicates the self-assembled characteristics of the carbon nanotube interconnection lines. The self-assembled characteristics of the bamboo-like carbon nanotube interconnection lines were evaluated using computer-aided image analysis

Fluorescence Detection of Microcapsule-Type Self-Healing, Based on Aggregation-Induced Emission

An extrinsic self-healing coating system containing tetraphenylethylene (TPE) in microcapsules was monitored by measuring aggregation-induced emission (AIE). The core healing agent comprised of methacryloxypropyl-terminated polydimethylsiloxane, styrene, benzoin isobutyl ether, and TPE was encapsulated in a urea-formaldehyde shell. The photoluminescence of the healing agent in the microcapsules was measured that the blue emission intensity dramatically increased and the storage modulus also increased up to 105 Pa after the photocuring. These results suggested that this formulation might be useful as a self-healing material and as an indicator of the self-healing process due to the dramatic change in fluorescence during photocuring. To examine the ability of the healing agent to repair damage to a coating, a self-healing coating containing embedded microcapsules was scribed with a razor. As the healing process proceeded, blue light fluorescence emission was observed at the scribed regions. This observation suggested that self-healing could be monitored using the AIE fluorescence.ope