An Artificial Motion and Tactile Receptor Constructed by Hyperelastic Double Physically Cross-Linked Silk Fibroin Ionoelastomer

Ionotronic artificial motion and tactile receptor (i-AMTR) is essential to realize an interactive human-machine interface. However, an i-AMTR that effectively mimics the composition, structure, mechanics, and multi-functionality of human skin, called humanoid i-AMTR, is yet to be developed. To bridge this technological gap, this study proposes a strategy that combines molecular structure design and function integration to construct a humanoid i-AMTR. Herein, a silk fibroin ionoelastomer (SFIE) with double cross-linked molecular structure is designed to mimic the composition and structure of human skin, thereby resolving the conflict of stretchability, softness, and resilience, suffered by many previously reported ionotronics. Functionally, electromechanical sensing and triboelectricity-based tactile perception are integrated into SFIE, to enable simultaneous perception of both motion and tactile inputs. By further leveraging the machine learning and Internet of Things (IoT) techniques, the proposed SFIE-based humanoid i-AMTR precisely senses the movement of human body and accurately sortball objects made of different materials. Notably, the success rate for 610 sorting tests reaches as high as 92.3%. These promising results essentially demonstrate a massive potential of humanoid i-AMTR in the fields of sorting robots, rehabilitation medicine, and augmented reality.     

Fine-Tuning Alkyl Chains on Quinoxaline Nonfullerene Acceptors Enables High-Efficiency Ternary Organic Solar Cells with Optimizing Molecular Stacking and Reducing Energy Loss

Material design of guest acceptor is always a big challenge for improving the efficiency of ternary organic solar cells (OSCs). Here, a pair of isomeric nonfullerene acceptors based on quinoxaline core, Qx–p-C₇H₈O and Qx–m-C₇H₈O, is designed and synthesized. By moving the alkoxy chain attached on side phenyl from meta-position to para-position, both π–π stacking distance and crystallinity are enhanced simultaneously. They obtain the uplifted lowest unoccupied molecular orbital level. Compared to Qx–m-C₇H₈O, Qx–p-C₇H₈O exhibits wider absorption spectrum and higher extinction coefficient. Using D18-Cl:N3 as host materials, the addition of guest acceptor Qx–p-C₇H₈O significantly improves the power conversion efficiency (PCE) from 17.61% to 18.49% because of higher open-circuit voltage (0.875 V) and short-circuit current density (27.85 mA cm⁻²). This can be attributed to the faster exciton dissociation, more balanced carrier mobility, fine fiber morphology, and lower energy loss in the ternary devices. However, Qx–m-C₇H₈O-based ternary device achieves relatively low PCE of 17.17% because this device shows extremely low electron mobility. The results indicate that molecular stacking, film morphology, etc., can be effectively modulated by fine-tuning the side chains of guest materials, which may be an effective design rule for further improving the PCE of OSCs.     

Paving the Way for High-Performance UVB-LEDs Through Substrate-Dominated Strain-Modulation

AlGaN-based ultraviolet-B light-emitting diodes (UVB-LEDs) exhibit great potential in phototherapy, vitamin D3 synthesis promotion, plant growth regulation, and so on. However, subjected to the excess compressive strain induced by the large lattice mismatch between multiple quantum wells (MQWs) and AlN, UVB-LEDs that simultaneously satisfy the requirements of high light output power (LOP), low working voltage, and excellent stability are rarely reported. Here, a substrate-dominated strain-modulation strategy is proposed. By precisely manipulating the strain in AlN grown on nano-patterned sapphire substrate (NPSS) to a slightly tensile one, the compressive strain in the following Al_0.55Ga_0.45N underlayer and Al_0.28Ga_0.72N/Al_0.45Ga_0.55N MQWs is successfully suppressed. As a result, an outstanding UVB-LED with a peak wavelength at 303.6 nm is achieved. The 20 × 20 mil² UVB-LED chip shows a wall-plug efficiency (WPE) of 3.27% under a forward current of 20 mA and a high LOP of 57.2 mW with an extremely low voltage of 5.87 V under a forward current of 800 mA. It is more exciting that the LOP degradation is as low as 17% after 1000 h operation under a forward current density of 75 A cm⁻², showing excellent stability. The here-developed UVB-LED, with a high LOP and excellent reliability, will definitely promote the applications of AlGaN-based UVB-LEDs.     

Functional Materials for Memristor-Based Reservoir Computing: Dynamics and Applications

The booming development of artificial intelligence (AI) requires faster physical processing units as well as more efficient algorithms. Recently, reservoir computing (RC) has emerged as an alternative brain-inspired framework for fast learning with low training cost, since only the weights associated with the output layers should be trained. Physical RC becomes one of the leading paradigms for computation using high-dimensional, nonlinear, dynamic substrates. Among them, memristor appears to be a simple, adaptable, and efficient framework for constructing physical RC since they exhibit nonlinear features and memory behavior, while memristor-implemented artificial neural networks display increasing popularity towards neuromorphic computing. In this review, the memristor-implemented RC systems from the following aspects: architectures, materials, and applications are summarized. It starts with an introduction to the RC structures that can be simulated with memristor blocks. Specific interest then focuses on the dynamic memory behaviors of memristors based on various material systems, optimizing the understanding of the relationship between the relaxation behaviors and materials, which provides guidance and references for building RC systems coped with on-demand application scenarios. Furthermore, recent advances in the application of memristor-based physical RC systems are surveyed. In the end, the further prospects of memristor-implemented RC system in a material view are envisaged.     

Regulation of Ionic Distribution and Desolvation Activation Energy Enabled by In Situ Zinc Phosphate Protective Layer toward Highly Reversible Zinc Metal Anodes

Despite the merits of high specific capacity, low cost, and high safety, the practical application of aqueous Zn metal batteries (AZMBs) is plagued by the dendritic growth and corrosion reaction of Zn metal anodes. To solve these issues, a Zn₃(PO₄)₂·4H₂O protective layer is in-situ constructed on Zn foil (Zn@ZnPO) by a simple hydrothermal method, avoiding the traditional slurry-casting process. The insulating and conformable ZnPO layer improves the wettability of Zn@ZnPO and aqueous electrolyte via decreasing the contact angle to 11.7^o. Compared with bare Zn, the Zn@ZnPO possesses a lower desolvation activation energy of 35.25 kJ mol^-1, indicating that the ZnPO fasters the desolvation of hydrated Zn²⁺ ions and thereby ameliorates their transport dynamics. Micro-morphology and structural characterization show that there are no dendrites forming on the post-cycling Zn@ZnPO anodes, and the interfacial ZnPO layer remains almost identical before and after cycles. It can be explained that the electrochemically stable ZnPO layer acts as an ionic modulator to enable the homogeneous distribution of Zn²⁺ ions, inhibiting the growth of Zn dendrites. Benefiting from these advantages, the Zn@ZnPO based symmetric and full cells deliver highly reversible Zn plating/stripping behavior and long cycling lifespans.     

5G价值面,BSS/OSS融合的下一站

随着移动通信与互联网技术的发展,传统通信业务已由单一的语音通信,发展为多元化、个性化的融合信息服务,通信产业价值链结构从以运营商为中心的模式向以用户体验为中心的模式转变。互联网与内容提供商以“内容驱动”为理念,灵活快速地迭代产品并响应用户需求,市场份额快速提升,这导致运营商在产业价值链中逐渐被“管道化”。在数字化转型过程中,运营商通过重构、抽象5G网络功能,实现了网络按需编排、灵活适配和快速部署的能力,并基于业务支撑系统（business support system,BSS）/运营支撑系统（operation support system,OSS）(BO)融合与以用户为中心的运营模式增强用户体验,以期实现在产业价值链中地位和价值的提升。在回顾通信产业价值链发展的基础上,分析了运营商价值提升所面临的挑战,提出了一种基于5G网络嵌入式服务的5G价值面体系架构,给出了典型应用场景,并为运营商5G价值面的演进提供了路径建议,助力运营商驶向BO融合的下一站。     

Structural and optical properties of AIN sputtering deposited on sapphire substrates with various orientations

AIN thin films were deposited on c-,a-and r-plane sapphire substrates by the magnetron sputtering technique.The in-fluence of high-temperature thermal annealing (HTTA) on the structural,optical properties as well as surface stoichiometry were comprehensively investigated.The significant narrowing of the (0002) diffraction peak to as low as 68 arcsec of AIN after HTTA implies a reduction of tilt component inside the AIN thin films,and consequently much-reduced dislocation densities.This is also supported by the appearance of E2(high) Raman peak and better Al-N stoichiometry after HTTA.Furthermore,the in-creased absorption edge after HTTA suggests a reduction of point defects acting as the absorption centers.It is concluded that HTTA is a universal post-treatment technique in improving the crystalline quality of sputtered AIN regardless of sapphire orienta-tion.     

视场非完全重叠的分布式雷达多目标跟踪方法

在探测能力、波形设计及天线指向等因素制约下,分布式雷达视场并非完全重合,由此造成的观测信息差异给后续信息融合带来了巨大挑战。该文基于高斯混合实现的集势概率假设密度(CPHD)滤波器,提出了一种视场部分重叠下的分布式雷达多目标跟踪方法。首先,利用多目标密度乘积切分出概率假设密度(PHD)中表征共同观测信息的部分;之后,标准的分布式融合(算术平均或几何平均融合)方法作用于切分出的共同观测目标信息以提升跟踪性能,补偿融合则作用于雷达单独观测目标信息以扩展视场范围。该文方法无须视场先验信息,能够适应雷达视场未知时的分布式融合多目标跟踪场景。仿真实验验证了所提出方法在未知、时变雷达视场下跟踪多目标的性能,表明了该文方法比基于高斯混合的聚类方法性能更好。