A series of liquid‐crystalline (LC) π‐‐conjugated oligothiophenes bearing three or two alkoxy chains at their extremities has been designed and synthesized. These polycatenar oligothiophenes form various LC nanostructures including smectic, columnar, and micellar cubic phases. These properties depend on the number and length of the terminal alkoxy chains. The hole mobilities for the oligothiophenes have been measured. The layered smectic and columnar structures are capable of transporting holes, leading to mobilities of up to 0.01 cm2 V−1 s−1. The columnar LC assemblies have also been explored to produce linearly polarized light‐emission. Fine red polarized fluorescence is observed from a uniaxially aligned film of the oligothiophenes. The redox properties of the oligothiophenes both in solutions and in films have been examined. The oligothiophenes exhibit electrochromism upon applying an oxidative potential. The present design strategy is useful for fabricating a variety of functional electro‐active molecular assemblies.
The antibacterial effect of a nanostructured film, known as “moth-eye film,” was investigated. The moth-eye film has artificially formed nano-pillars, consisting of hydrophilic resin with urethane acrylate and polyethylene glycol (PEG) derivatives, all over its surface that replicates a moth’s eye. Experiments were performed to compare the moth-eye film with a flat-surfaced film produced from the same materials. The JIS Z2801 film-covering method revealed that the two films produced a decrease in Staphylococcus aureus and Esherichia coli titers of over 5 and 3 logs, respectively. There was no marked difference in the antibacterial effects of the two surfaces. However, the antibacterial effects were reduced by immersion of the films in water. These results indicated that a soluble component(s) of the resin possessed the antibacterial activity, and this component was identified as PEG derivatives by time-of-flight secondary ion mass spectrometry (TOF-SIMS) and Fourier transform infrared spectroscopy (FT-IR). When a small volume of bacterial suspension was dropped on the films as an airborne droplet model, both films showed antibacterial effects, but that of the moth-eye film was more potent. It was considered that the moth-eye structure allowed the bacteria-loaded droplet to spread and allow greater contact between the bacteria and the film surface, resulting in strong adherence of the bacteria to the film and synergistically enhanced bactericidal activity with chemical components. The antibacterial effect of the moth-eye film has been thus confirmed under a bacterial droplet model, and it appears attractive due to its antibacterial ability, which is considered to result not only from its chemical make-up but also from physical adherence.
We have developed a novel reflective LCD without polarizers, which is sure to provide excellent visibility (reflectance = 50%, CR = 10:1). Moreover, we have also achieved extremely low power consumption of 10 microwatts to introduce low frequency driving (less than 1Hz) without flicker and image sticking. These characteristics were realized to combine pixel memory circuit and new PNLC material. IntroductionInformation displays have widely prevailed among our daily life. That means, it demands much effort to broaden application fields of electronic displays and to develop the information society further, and therefore the importance of the low power consumption is arising more than ever. Since the power consumption of the conventional electronic displays is still high enough to limit their usage pattern or usage environment. In particular, such functions as the reflective display, the low frame rate drive and the ability to memorize images are quite effective to realize the display consuming low electric power. The display images can be memorized by using the electrophoretic display [1] or the cholesteric liquid crystal display [2], but those displays have required relatively high driving voltages and slow responses.From these viewpoints, the combination of the reflective type of liquid crystal display (RLCD) [3] and the drive scheme such as the low frame rate drive [4] or the pixel-memory circuit [5-6] should be a promising candidate. Since the power consumption of an LCD module generally depends on driving frequency, the lower the frame rate gets, the lower power the module consumes. And the pixel-memory circuit technology enables the module to have any images memorized at the pixels with the data driver suspended.An RLCD using polymer network liquid crystals (PNLC) [7] is the display system to control transmission or scattering of incoming light ray without polarizers. Its remarkable features are high light utilization efficiency due to polarizer-free system and low level of dependence on viewing angle. And a PNLC is one of solutions to realize an energy saving, paper-like display.In the meantime, a PNLC has had a couple of challenges for TFT drive, which are high driving voltage, slow response and low voltage holding ratio. However recent progress of the PNLC materials enables TFT drive of a PNLC by improving the properties above [8].Our objective is to develop an ultra low-power-consumption RLCD with excellent visibilities by using the one-bit pixel memory technology and the PNLC. PrincipleOur newly developed display is composed of the PNLC layer formed between a transparent electrode and mirror reflective pixel electrodes, and the one-bit pixel memory circuits embedded in the pixel area under the reflective mirror electrodes. Pixel Memory TechnologyThe system block diagram of our newly developed pixel memory display is shown in Figure 1. The interface of this display is very simple, because only 5 input lines are necessary for operating this display including power supplies. Timing generator with a 3-line se...
We have developed an over 60-inch size Moth-eye anti-reflection surface, which has original shaped nanostructures. The minimum reflectance was 0.02% and the average was less than 0.04% with little wavelength dependence. Moreover an anti-glare function was added. The 60-inch LCD applied AG Moth-eye surface had an excellent visibility in bright environments.
BackgroundRecent studies report that surfaces displaying micrometer- or nanometer-sized undulating structures exhibit antibacterial effects. In previous work, we described the use of an advanced nanofabrication technique to generate an artificial biomimetic Moth-eye film by coating a polyethylene terephthalate (PET) film with nanoscale moth-eye protrusions made from a hydrophilic resin. This moth-eye film exhibited enhanced antibacterial effects in in vitro experiments. The aim of the present study was to verify the antibacterial efficacy of the Moth-eye film in practical environments.Materials and methodsThe antibacterial effects of three types of film (Moth-eye film, Flat film, and PET film) were compared. Sample films were pasted onto hand washing basins at the testing locations. After several hours, bacteria were collected from the surface of the sample films with one of three kinds of culture media stamper (to permit identification of bacterial species). The stampers were incubated for 48 hours at 35°C, and the numbers of colonies were counted.Results and discussionThe number of common bacteria including E. coli and S. aureus obtained from the Moth-eye film was significantly lower than those from the PET film (p<0.05) and Flat film at 1 hour (p<0.05). This study found that the Moth-eye film showed a long-term (6h) antibacterial effect and the Moth-eye structure (PET coated with nanoscale cone-shaped pillars) demonstrated a physical antibacterial effect from earlier time points. Therefore, the Moth-eye film appears to have potential general-purpose applications in practical environments.
Acoustic resonance technique has been applied to monitor the fatigue damage process of steel pipes exposed to rotating bending fatigue. The technique incorporates a superheterodyne spectrometer and an electromagnetic acoustic transducer ͑EMAT͒. The EMAT was newly developed for this purpose, and uses the magnetostrictive mechanism of ferromagnetic metals and excites and detects axial shear waves traveling around the sample pipe with axial polarization. Noncontact ultrasonic spectroscopy permits the accurate determination of the resonant frequency and the attenuation coefficient throughout the fatigue life. The attenuation coefficient shows a sharp peak around 80%-90% of the life. The evolution is interpreted as reflecting dislocation multiplication, depinning, and formation of cell structures, which is supported by transmission electron microscopy observations.
We have investigated the dynamics of the process of annihilation of a wedge disclination pair generated in a nematic cell with hybrid alignment, by quenching it from its isotropic phase. The time evolution of the separation between the defect pair can be classified into two stages: the early stage, with a stringlike pattern of schlieren texture immediately after a defect pair is generated; and the late stage, with a round pattern before the defect pair is annihilated. The experimental results show that the separation between the defect pair decreases linearly with time in the early stage, and then diminishes to zero in proportion to the square root of the time to coalesce the defect pair in the late stage; these are easily explained with a two-dimensional phenomenological model by including an additional field with an ordering effect. By numerical simulation, we have also studied the annihilation dynamics of a three-dimensional equation of motion based on the Frank elastic energy without a phenomenological ordering field. The simulation results are in good agreement with the experimental ones, which indicates that the defect pair behavior in the early stage is attributed to the hybrid alignment, with a coupling energy between the tilt angle and the azimuthal angle. From a comparison between the phenomenological model with the ordering field and the numerical simulation, we can clarify the molecular origin of the ordering field, which has been introduced to explain the unusual annihilation process in the early stage.
We report and discuss UV patterning technology of nanoLED with ultra‐high‐resolution. Additionally, we also report on the performances of the ultra‐high‐resolution nanoLED panel for ARJVR by UV patterning technology.
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