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The direction-dependent dual-mechanism refractive index sensor composed of the forward strip graphene and backward composite photonic structure with black phosphorus (BP) is proposed. The linear correlation between the absorption by different mechanisms and the refractive index of the analyte can be realized for two incident directions. The simulated results show that the sensitivities of the forward incidence with the refractive index measurement ranges of 1.2 - 1.6 and 1.6 - 1.9 are 3.135 THz/RIU (refractive index unit) and 1.135 THz/RIU. The sensitivities of the backward incidence with refractive index detection zones 1.2 - 1.5 and 1.6 - 2.0 are 9.500 THz/RIU and 14.650 THz/RIU. In addition, the forward incidence owns more appropriate linearity while the backward incidence possesses better angular stability. These results can find applications in reconfigurable integrated photodetectors for refractive index sensing. [ABSTRACT FROM AUTHOR]

A dual-mechanism energy storage strategy is proposed, involving the electrochemical process of sodium ion battery (SIB) and sodium metal battery (SMB). This strategy is expected to achieve a higher capacity than SIB, and obtain dendrite-free growth of SMB with a well-designed anode. Here, self-constructed bismuth with "sodiophilic" framework and rapid ion transmission characteristics is employed as the sodium host (anode) integrating alloy/de-alloy and plating/stripping process that suppresses the dendrite growth and overcomes the limited capacity of traditional anode. Benefited from this, the capacity (capacity contributed by alloy and plating of sodium in total) of 2000 mAh g -1 can be reached, which can retain up to 800 h at 1 A g -1 . Also, the capacity of 3100 mAh g -1 can be achieved that is ≈7.7 times than that of alloyed-bismuth (Bi). This work proposes a dual-mechanism strategy to tackle the dilemma of high-performance sodium (Na) storage devices, which opens a new avenue for the development of next-generation energy storage device., (© 2023 Wiley-VCH GmbH.)

A multicolor fluorescent probe BNO for measuring intracellular pH is designed and synthesized, which is the first pH probe with a dual response mechanism combining an excited state intramolecular proton transfer (ESIPT) process and an intramolecular charge transfer (ICT) process. The probe shows negligible fluorescence at neutral and weak alkaline pH due to fluorescence quenching caused by ESIPT, and a sharp fluorescence enhancement in both acidic and strong alkaline environments. Meanwhile, it responds to pH changes with different emissions (green at acidic range, cyan at alkaline range). BNO is able to indicate pH variations in a wide range of 3.9–13.0. It is also capable of distinguishing intracellular pH values with high sensitivity. Furthermore, the probe exhibits favorable two-photon photophysics and high photostability, thus it is successfully applied to trace the dynamic change of intracellular pH with two-photon microscopy (TPM). The dual-mechanism strategy may be expanded to design other fluorescent probes. [ABSTRACT FROM AUTHOR]

This paper introduces a protective sandwich structure with simultaneous auxetic compression and tension behaviour (termed as the dual-mechanism) in the core. To achieve the proposed mechanism, a novel architected cellular structure, named as the dual-mechanism auxetic (DMA), was developed. The protective performance of the DMA was examined by subjecting the DMA-core sandwich panel (DMASP) to blast loading through computational modelling. A series of dynamic numerical models were developed in LS-DYNA, and validated with the past experimental results. The protective performance of the DMASP was evaluated comprehensively based on energy absorption, stress mitigation, and deflection control. Moreover, the protective performance of the DMASP was compared with an equivalent areal density solid plate. In addition, parametric studies were conducted to investigate effects of various design parameters and explosive environments on the protective efficacy of the DMASP. The numerical simulations uncovered that, in addition to high energy absorption capacity of the DMA core, the dual-mechanism was beneficial to mitigate high stress transfer to the protected structure by redirecting stress in the lateral direction through auxetic tensile behaviour. Furthermore, the DMASP offered better protective performance than the equivalent solid structure with respect to all the evaluation criteria under different blast loading scenarios. [ABSTRACT FROM AUTHOR]

Soft actuators have attracted a lot of attention owing to their biomimetic performance. However, the development of soft actuators that are easily prepared from readily available raw materials, conveniently utilized, and cost-efficient is still a challenge. Here, we present a simple method to fabricate a polyethylene-based soft actuator. It has controllable anisotropic structure and can realize multiple motions, including bidirectional bending and twisting based on dual mechanisms, which is a rare phenomenon. Especially, the soft actuators can response at a very small temperature difference (Δ T ≥ 2.3 °C); therefore, even skin touch can quickly drive the actuator, which greatly broadens its applications in daily life. The soft actuator could demonstrate a curvature up to 7.8 cm -1 accompanied by powerful actuation. We have shown that it can lift an object 27 times its own weight. We also demonstrate the application of this actuator as intelligent mechanical devices.