Design, Assembly, and Fabrication of Two-Dimensional Nanomaterials into Functional Biomimetic Device Systems

Diverse functioning biosystems in nature have inspired us and offered unique opportunities in developing novel concepts as well as new class of materials and devices. The design of bioinspired functional materials with tailored properties for actuation, sensing, electronics, and communication has enabled synthetic devices to mimic natural behavior. Among which, artificial muscle and electronic skin that enable to sense and respond to various environmental stimuli in a human-like way have been widely recognized as a significant step toward robotics applications. Polymer materials have previously been dominant in fabricating such functional biomimetic devices owing to their soft nature. However, lacking multifunctionality, handling difficulty, and other setbacks have limited their practical applications. Recently, versatile and high-performance two-dimensional (2D) materials such as graphene and its derivatives have been studied and proven as promising alternatives in this area. In this chapter, we highlight the recent efforts on fabrication and assembly of 2D nanomaterials into functional biomimetic systems. We discuss the structure-function relationships for the development of 2D materials–based biomimetic devices, their tailoring property features, and their variety of applications. We start with a brief introduction of artificial functional biomimetic materials and devices, then summarize some key 2D materials–based systems, including their fabrication, properties, advantages and demonstrations, and finally present concluding remarks and outlook

Graphene-Paper Based Electrochemical Sensors

Graphene paper as a new form of graphene-supported nanomaterials has received worldwide attention since its first report in 2007. Due to their high flexibility, lightweight and good electrical conductivity, graphene papers have demonstrated the promising potential for crucial applications in electrochemical sensors and energy technologies among others. In this chapter, we present some examples to overview recent advances in the research and development of two-dimensional (2D) graphene papers as new materials for electrochemical sensors. The chapter covers the design, fabrication, functionalization and application evaluations of graphene papers. We first summarize the mainstream methods for fabrication of graphene papers/membranes, with the focus on chemical vapour deposition techniques and solution-processing assembly approaches. A large portion of this chapter is then devoted to the highlights of specific functionalization of graphene papers with polymer and nanoscale functional building blocks for electrochemical-sensing purposes. In terms of electrochemical-sensing applications, the emphasis is on enzyme-graphene and nanoparticle-graphene paper-based systems for the detection of glucose. We finally conclude this chapter with brief remarks and outlook

Direct and Indirect Recycling Strategies of Expired Oxytetracycline for the Anode Material in Lithium Ion Batteries

It is well-known that the antibiotics inhibit the wide spread of various infection diseases and guarantee the life safety of many patients. However, various waste antibiotics into the environment also pose the great challenges of the environmental contamination and the ecological poison. Unreasonable disposal of expired antibiotics is one of the main sources of waste antibiotics in the ecological environment. For this reason, in order to focus on the circular economy of such highly refined medical grade chemicals, expired oxytetracycline was recycled for the anode active material in lithium ion batteries (LIBs) by direct and indirect strategies. That is, it was directly used as the anode active material or recycled by two-step carbonization for LIBs anode. Furthermore, the effect of these two strategies on the electrochemical performances was also discussed. Both anode materials showed their individual advantages and high feasibility for LIBs anode. For example, both them delivered the satisfactory Li-storage performances. Additionally, the direct route possessed lower recycling cost and high recovery rate, while the application range of carbon material in the indirect route was broader

Federated Learning in Big Model Era: Domain-Specific Multimodal Large Models

Multimodal data, which can comprehensively perceive and recognize the physical world, has become an essential path towards general artificial intelligence. However, multimodal large models trained on public datasets often underperform in specific industrial domains. This paper proposes a multimodal federated learning framework that enables multiple enterprises to utilize private domain data to collaboratively train large models for vertical domains, achieving intelligent services across scenarios. The authors discuss in-depth the strategic transformation of federated learning in terms of intelligence foundation and objectives in the era of big model, as well as the new challenges faced in heterogeneous data, model aggregation, performance and cost trade-off, data privacy, and incentive mechanism. The paper elaborates a case study of leading enterprises contributing multimodal data and expert knowledge to city safety operation management , including distributed deployment and efficient coordination of the federated learning platform, technical innovations on data quality improvement based on large model capabilities and efficient joint fine-tuning approaches. Preliminary experiments show that enterprises can enhance and accumulate intelligent capabilities through multimodal model federated learning, thereby jointly creating an smart city model that provides high-quality intelligent services covering energy infrastructure safety, residential community security, and urban operation management. The established federated learning cooperation ecosystem is expected to further aggregate industry, academia, and research resources, realize large models in multiple vertical domains, and promote the large-scale industrial application of artificial intelligence and cutting-edge research on multimodal federated learning

The Recovery of the Waste Cigarette Butts for N-Doped Carbon Anode in Lithium Ion Battery

As one of the common life garbages, about 4.5 trillion waste cigarette butts are produced and randomly discarded every year due to the addiction to the nicotine and the need of the social intercourse. Such a treatment would result in the waste of the resources and the environmental pollution if they weren't reasonably recycled in time. Herein, the waste cigarette butts were recycled in form of N-doped carbon powders with high economic value-added via one-step facile carbonization at 800°C for 2 h in the inert N2 atmosphere. The waste-cigarette-butts-derived black carbon powders were characterized by scanning electron microscope (SEM), N2 adsorption/desorption, and X-ray photoelectron spectroscopy (XPS). Furthermore, the corresponding electrochemical performances as the anode in lithium ion battery (LIB) were also investigated by galvanostatic charge/discharge, cyclic voltammetry (CV), and alternating current (AC) impedance. The results suggested that the recycled N-doped waste cigarette butts carbon (WCBC) powders consisted of major carbon and minor residual N-containing and O-containing functional groups, and the corresponding specific surface area was about 1,285 m2·g−1. Furthermore, the reversible specific discharge capacity was about 528 mAh·g−1 for 100 cycles at 25 mA·g−1 and about 151 mAh·g−1 even at 2,000 mA·g−1 for 2,500 cycles. Additionally, full cell performances were also satisfactory, indicating high feasibility. N-doping effect (such as additional active sites and higher electronic conductivity) and the residual O-containing functional groups may be responsible for the satisfactory electrochemical performances, which offered good inspiration and strategy to develop the green energy and circular economy

Evaluating the impact of groundwater on cotton growth and root zone water balance using Hydrus-1D coupled with a crop growth model

Groundwater is an important factor that needs to be considered when evaluating the water balance of the soil-plant-atmosphere system and the sustainable development of arid oases. However, the impact of shallow groundwater on the root zone water balance and cotton growth is not fully understood. In this study, we have first analyzed the influence of the groundwater table depth on the seasonal maximum leaf area index of cotton, the average seasonal water stress, cotton yield, actual transpiration, actual evaporation, and capillary rise using experimental data collected at the Aksu water balance station, in Xinjiang, northwest of China and the Hydrus-1D variably-saturated soil water flow model coupled with a simplified crop growth model from SWAT. The coupled model has been first calibrated and validated using field observations of soil water content, leaf area index, cotton height, the above ground biomass, and cotton yield comparisons between measured and modeled variables have shown a reasonable agreement for all variables. Additionally, with a validated model, we have carried out numerical experiments from which we have concluded that groundwater is a major water resource for cotton growth in this region. The capillary rise from groundwater contributes almost 23% of crop transpiration when the average groundwater depth is 1.84. m, which is the most suitable groundwater depth for this experimental site. We have concluded that cotton growth and various components of the soil water balance are highly sensitive to the groundwater table level. Different positions of the groundwater table showed both positive and negative effects on cotton growth. Likewise, cotton growth has a significant impact on the capillary rise from groundwater. As a result, groundwater is a crucial factor that needs to be considered when evaluating agricultural land management in this arid region. The updated Hydrus-1D model developed in this study provides a powerful modeling tool for evaluating the effects of the groundwater table on local land management

Lattice-contraction triggered synchronous electrochromic actuator.

Materials with synchronous capabilities of color change and actuation have prospects for application in biomimetic dual-stealth camouflage and artificial intelligence. However, color/shape dual-responsive devices involve stimuli that are difficult to control such as gas, light or magnetism, and the devices show poor coordination. Here, a flexible composite film with electrochromic/actuating (238° bending angle) dual-responsive phenomena, excellent reversibility, high synchronization, and fast response speed (< 5 s) utilizes a single active component, W18O49 nanowires. From in situ synchrotron X-ray diffraction, first principles calculations/numerical simulations, and a series of control experiments, the actuating mechanism for macroscopic deformation is elucidated as pseudocapacitance-based reversible lattice contraction/recovery of W18O49 nanowires (i.e. nanostructure change at the atomic level) during lithium ion intercalation/de-intercalation. In addition, we demonstrate the W18O49 nanowires in a solid-state ionic polymer-metal composite actuator that operates stably in air with a significant pseudocapacitive actuation