RESUMEN
Research on liquid metals has been steadily garnering more interest in recent times, especially in flexible electronics applications because of their properties like possessing high conductivity and being liquid state at room temperature. The unique properties afforded by such materials at low temperatures can compensate for the limitations of stretchable electronic devices, particularly robustness and their fluidic property, which can enhance the flexibility and deformation of these devices. Therefore, interest in liquid-metal nanoparticles and liquid metals with nanocomposites has enabled research into their fabrication technologies as well as utilisation in fields such as chemistry, polymer engineering, computational modelling, and nanotechnology. In particular, in flexible and stretchable electronic device applications, the research attention is focused on the fabrication methodologies of liquid-metal nanoparticles and liquid metals containing nanocomposites. This review attempts to summarise the available stretchable and flexible electronics applications that use liquid-metal nanoparticles as well as liquid metals with nanomaterial additives.
RESUMEN
Stretchable physical sensors are crucial for the development of advanced electrical systems, particularly wearable devices and soft robotics. Currently available stretchable sensors that detect both pressure and strain are based on piezoelectric, piezoresistive, or piezocapacitive effects. The range of pressure sensing is 1-800 kPa with large deformations being within the range of deformations of parts of the human body, such as elbows and knees. However, these devices cannot easily allow simultaneous and independent detection of pressure and strain with sensor arrays at large tensions (> 50%) because strain affects the pressure signal. In this study, we propose a monolithic silicone-based array of pressure and strain sensors that can simultaneously and independently detect the in-plane biaxial tensile deformation and pressure. To realize these functionalities, the deformation of the device structure was optimized using a hetero-silicone substrate made of two types of silicone with different hardness characteristics and porous silicone bodies. In addition, the resistances of the sensors were controlled by adjusting a mixture based on carbon nanoparticles to improve the sensitivity and independence between the pressure and strain sensors. These concepts demonstrate the potential of this approach and its compatibility with the current architectures of stretchable physical sensors.
RESUMEN
To generate bright water-window (WW) soft x rays (2.3-4.4 nm), gold slab targets were irradiated with laser pulses (1064 nm, 7 ns, 1 J). Emission spectroscopy showed that the introduction of low-pressure nitrogen enhanced the soft x-ray yield emitted from the laser-produced Au plasma. The intensity of the WW x-ray transported in a 400-Pa N2 atmosphere from the laser-produced plasma increased by 3.8 times over that in vacuum. Considering a strong x-ray absorption, the x-ray yield emitted directly from the Au plasma in the N2 gas was evaluated to be 13 times higher than that in vacuum. Although similar measurements were made for various gases, only N2 gas causes an increase in a soft x-ray yield. The processes leading to this enhancement mechanism were revealed by using hydrodynamic simulation and atomic structure codes.
RESUMEN
To develop laser-ignition technology, transparent glass plates were artificially sooted and irradiated repetitively by laser from the front (sooted) and back sides separately. Generally, the back-side irradiation was more effective at soot removal. However, the cleaning effect was saturated after thousands of laser shots. Although the saturated soot quantity was a decreasing function of the laser fluence per pulse, its magnitude remained the same for both front-side and back-side irradiations. In examining several soot-removal mechanisms proposed so far, it was found that the aerodynamic force produced by the flow induced by the laser heating of the soot was the most plausible mechanism.
RESUMEN
For improving the laser absorption efficiency in laser ignition, the transmitted laser light was returned to the laser-produced plasma by using a corner cube. In the experiments, the transmitted light was reinjected into the plasma at different times. The laser absorption efficiency was found to be substantially improved when the transmitted light was reinjected into the plasma after adequate plasma expansion. Furthermore, through visualization experiments on gas-dynamics phenomena, it was found that the reinjection of the transmitted light affected not only the laser absorption efficiency but also the gas dynamics after breakdown, and thereby the initial flame kernel development.
RESUMEN
For correct functioning of the nervous system, the appropriate number and complement of neuronal cell types must be produced during development. However, the molecular mechanisms that regulate the production of individual classes of neurons are poorly understood. In this study, we investigate the function of the thrombospondin-1-like glycoprotein, Nel (neural epidermal growth factor [EGF]-like), in the generation of retinal ganglion cells (RGCs) in chicks. During eye development, Nel is strongly expressed in the presumptive retinal pigment epithelium and RGCs. Nel overexpression in the developing retina by in ovo electroporation increases the number of RGCs, whereas the number of displaced amacrine cells decreases. Conversely, knockdown of Nel expression by transposon-mediated introduction of RNA interference constructs results in decrease in RGC number and increase in the number of displaced amacrine cells. Modifications of Nel expression levels do not appear to affect proliferation of retinal progenitor cells, but they significantly alter the progression rate of RGC differentiation from the central retina to the periphery. Furthermore, Nel protects RGCs from apoptosis during retinal development. These results indicate that Nel positively regulates RGC production by promoting their differentiation and survival during development.
