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The sensor response of pressure-sensitive conductive elastomers using polymeric materials can be adjusted by altering the type and quantity of fillers used during manufacturing. Another method involves modifying the surface shape of the elastomer. This study investigates the sensor response by altering the surface shape of an electrode using a readily available pressure-sensitive conductive elastomer. By employing an oxygen-free copper electrode with a flat surface (with surface roughness parameters Ra = 0.064 μm and Rz = 0.564 μm) as a baseline, we examined the sensor system's characteristics. Electrodes were fabricated with triangular wave concavo-convex surfaces, featuring tip angles of 60, 90, and 120°. Improved sensor responses were observed with electrodes having tip angles of 60 and 90°. Additionally, even with varying conductive properties of elastomers, the conductance of the elastomer sensor increased similarly when using an electrode with a 90° tip angle. This study demonstrates the potential for expanding the applications of conductive elastomer sensors, highlighting the noteworthy improvement in sensor response and performance achieved by altering the surface shape of electrodes used with commercially available conductive elastomers. [ABSTRACT FROM AUTHOR]

The pressure-sensing mechanisms of conductive elastomers, such as conductive networks, and tunneling effects within them have been extensively studied. However, it has become apparent that external pressure can significantly impact the contact area of polymeric materials. In this study, we will employ a commercially available conductive elastomer to investigate changes in resistance and contact surface under external pressure. Resistance measurements will be taken with and without applying conductive grease to the surface of the elastomer. This allows us to observe changes in resistance values associated with pressure variations. Furthermore, as pressure is applied to the conductive elastomer, the contact area ratio increases. Such an increase in the contact area and its correlation to changes in conductance values will be assessed. [ABSTRACT FROM AUTHOR]

In this study, the stability of a sampled‐value control system with time‐ and state‐dependent disturbance and aperiodic sampling is investigated. To expand the application class of the sampled‐value controller, the local stability on a compact set is considered under the assumption of local Lipschitz continuity on the compact set. Because the assumption is weaker than the global Lipschitz continuity, the proposed stability analysis is applicable to a wider class of controlled systems. Global stability under the assumption of global Lipschitz continuity is also considered. The effectiveness of the derived stability condition is verified by conducting numerical simulations with some control parameters variations such as the disturbance magnitude and sample interval. [ABSTRACT FROM AUTHOR]

In this work, the tensile characteristics of a 0.2-mm-thick polypropylene (PP) sheet subjected to indentation with virgin and blunt knives (apex angle, α=42◦; tip thickness, w=6 and 20 μm, respectively), were experimentally investigated. To determine the effect of mechanical condition, such as the notched depth and the profile of the root surface, on the breaking behavior of the half-cut PP specimen, the tensile testing of the half-cut specimen was carried out by varying the indentation depth and tensile velocity. By the experiments, the breakage behavior of the scored (half-cut) zone was determined by varying the indentation depth, tip thickness of the blade, and elongation rate. A kind of crazing or cracking by the blunt knife decreased the tensile resistance and burr elongation for an indentation depth larger than 0.9, whereas the work hardening by the blunt knife increased these properties for an indentation depth less than 0.8. When a blunt knife was used at a high elongation rate larger than 0.01 s-1, the half-cut zone of the PP sheet exhibited brittle fracture, i.e., the tensile resistance and burr elongation decreased. [ABSTRACT FROM AUTHOR]

Organic-inorganic hybrid lead halide perovskite quantum dots (QDs) have various excellent optical properties, and they have drastically enhanced the field of light-emitting diode (LED) research. However, red-emissive CH 3 NH 3 (MA) PbI 3 QDs have worse optical properties compared with those of green-emissive MAPbBr 3 QDs due to their instability under high-moisture and high-temperature conditions. Therefore, it is quite difficult to prepare MAPbI 3 QDs with good optical properties via bottom-up methods using conditions involving high temperature and high-solubility solvents. On the other hand, top-down methods for preparing MAPbI 3 QDs under an air atmosphere have attracted attention; however, there are issues, such as PL emission with a wide FWHM being obtained due to the wide particle-size distribution. In this research, red-emissive MAPbI 3 QDs were prepared via an ultrasound-assisted bead milling (UBM) method, and the MAPbI 3 QDs were purified using various carboxylate esters. As a result, we solved the issue of the wide particle-size distribution unique to top-down methods via purifying the MAPbI 3 QDs, and they achieved the following excellent optical properties: a FWHM of 44 to 48 nm and a PLQY of over 60%. Notably, a fabricated LED device with MAPbI 3 QDs purified using methyl acetate showed a PL peak at 738 nm and a FWHM of 49 nm, resulting in an excellent EQE value of 3.2%., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Organic materials have attracted considerable attention in nonlinear optical (NLO) applications as they have several advantages over inorganic materials, including high NLO response, and fast response time as well as low-cost and easy fabrication. Lithium-containing C 60 (Li@C 60 ) is promising for NLO over other organic materials because of its strong NLO response proven by theoretical and experimental studies. However, the low purity of Li@C 60 has been a bottleneck for applications in the fields of solar cells, electronics and optics. In 2010, highly purified Li@C 60 was finally obtained, encouraging further studies. In this study, we demonstrate a facile method to fabricate thin films of Li@C 60 and their strong NLO potential for high harmonic generation by showing its comparatively strong emission of degenerate-six-wave mixing, a fifth-order NLO effect., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)