Electronic skin can detect minute electrical potential changes in the human skin and represent the body's state, which is critical for medical diagnostics and human–computer interface development. On ...the other hand, sweat has a significant effect on the signal stability, comfort, and safety of electronic skin in a real‐world application. In this study, by modifying the cation and anion of a poly(ionic liquid) (PIL) and employing a spinning process, a PIL‐based multilayer nanofiber membrane (PIL membrane) electronic skin with a dual gradient is created. The PIL electronic skin is moisture‐wicking and breathable due to the hydrophilicity and pore size‐gradients. The intrinsically antimicrobial activities of PILs allow the safe collection of bioelectrical signals from the human body, such as electrocardiography (ECG) and electromyography (EMG). In addition, a robotic hand may be operated in real‐time, and a preliminary human–computer interface can be accomplished by simple processing of the collected EMG signal. This study establishes a novel practical approach for monitoring and using bioelectrical signals in real‐world circumstances via the multifunctional electronic skin.
A dual‐gradient poly(ionic liquid) electronic skin with moisture‐wicking, breathable, and antibacterial properties is prepared. Sweat can be delivered to the outside, away from the skin, keeping the electrode‐skin interface dry, ensuring stable and safe collection of bioelectric signals, further enabling real‐time control of a robotic hand. This work provides an unprecedented practical strategy for monitoring and utilization of bioelectrical signals under real conditions.
Field test of electro-osmotic consolidation with area of 800 square meters was carried out using electrokinetic geosynthetics (EKG). By introducing this field test, new concepts and solutions of ...difficulties in large scale application of electro-osmosis is introduced. Strategies of building smart DC power source to meet the large current intensity requirement of electro-osmosis are introduced. Roll polling program is a key program for the control system of smart DC power source. It reduces the requirement of current intensity to 1/3; it also decreases the energy consumption to less than 1 kW·h/m3. Design method for electro-osmotic consolidation is demonstrated while designing a field test. It is based on the energy level gradient theory. Design includes power estimation, wires and cables configuration, treatment time estimation and settlement estimation. The field test show that large scale application of electro-osmotic consolidation is feasible with acceptable power requirement and energy consumption. Electro-osmosis can accelerate consolidation and achieve better consolidation effect.
•Strategies of building smart DC power source to meet the large current intensity requirement of electro-osmosis are introduced.•Roll polling program developed in this paper reduces the requirement of current intensity to 1/3; it also decreases the energy consumption to less than 1 kW h/m3.•Design method for electro-osmotic consolidation using EKG based on the energy level gradient theory is demonstrated while designing the field test. Design method includes power estimation, wires and cables configuration, treatment time estimation and settlement estimation.
Porous ionic polymers (PiPs) are newly emerging organic porous polymers. In sharp contrast to charge-neutral porous polymers, ionic moieties are either incorporated into the polymer backbone, or are ...covalently attached to a polymeric framework. Therefore, their physicochemical properties, functional groups, and active sites can be easily modified through screening of building blocks and ionic tectons. Meanwhile, their surface area, pore size, and pore volume can also be tuned by counterions exchange. Intrinsic functionalization further broadens the application range of the PiPs. This review will describe the recent advancements with regard to PiPs, and their development in the area of gas adsorption, catalysis, antibacterial applications and water purification.
Sinter ore is the main raw material of the blast furnace, and burn-through point (BTP) has a direct influence on the yield, quality, and energy consumption of the ironmaking process. Since iron ore ...sintering is a very complex industrial process with strong nonlinearity, multivariable coupling, random noises, and time variation, traditional soft-sensor models are hard to learn the knowledge of the sintering process. In this article, a multistep prediction model, called denoising spatial-temporal encoder-decoder, is developed to predict BTP in advance. First, the mechanism analysis is carried out to determine the relevant-BTP variables, and the BTP prediction is defined as a sequence-to-sequence modeling problem. Second, motivated by the random noises of industrial data, a denoising gated recurrent unit (DGRU) is designed to alleviate the impact of noise by adding a denoising gate into the GRU. In this case, the encoder with DGRU can better extract the latent variables of original sequence data. Then, spatial-temporal attention is embedded into the decoder to simultaneously capture the time-wise and variable-wise correlations between the latent variables and the target variable BTP. Finally, the experimental results on the real-world dataset of a sintering process demonstrated that the integrated multistep prediction model is effective and feasible.
Human fingers exhibit both high sensitivity and wide tactile range. The finger skin structures are designed to display gradient microstructures and compressibility. Inspired by the gradient ...mechanical Young's modulus distribution, an electric‐field‐induced cationic crosslinker migration strategy is demonstrated to prepare gradient ionogels. Due to the gradient of the crosslinkers, the ionogels exhibit more than four orders of magnitude difference between the anode and the cathode side, enabling gradient ionogel‐based flexible iontronic sensors having high‐sensitivity and broader‐range detection (from 3 × 102 to 2.5 × 106 Pa) simultaneously. Moreover, owing to the remarkable properties of the gradient ionogels, the flexible iontronic sensors also show good long‐time stability (even after 10 000 cycles loadings) and excellent performance over a wide temperature range (from −108 to 300 °C). The flexible iontronic sensors are further integrated on soft grips, exhibiting remarkable performance under various conditions. These attractive features demonstrate that gradient ionogels will be promising candidates for smart sensor applications in complex and extreme conditions.
Inspired by gradient modulus distribution of human fingers, gradient ionogels are prepared by an electric‐field‐induced cationic crosslinkers migration strategy. The gradient of the modulus distribution enables the gradient‐ionogel‐based flexible sensors to demonstrate high sensitivity and broader‐range detection simultaneously. Moreover, the flexible iontronic sensors also show good longtime stability and excellent performance over a wide temperature range.
Conspectus The rise of organic bioelectronics efficiently bridges the gap between semiconductor devices and biological systems, leading to flexible, lightweight, and low-cost organic bioelectronic ...devices suitable for health or body signal monitoring. The introduction of organic semiconductors in the devices can soften the boundaries between microelectronic systems and dynamically active cells and tissues. Therefore, organic bioelectronics has attracted much attention recently due to the unique properties and promising applications. Organic thin film transistors (OTFTs), owing to their inherent capability of amplifying received signals, have emerged as one of the state-of-the-art biosensing platforms. The advantages of organic semiconductors in terms of synthetic freedom, low temperature solution processing, biocompatibility, and mechanical flexibility render OTFTs ideal transducers for wearable electronics, e-skin, and implantable devices. How to realize highly sensitive, selective, rapid, and efficient signal capture and extraction of biological recognition events is the major challenge in the design of biosensors. OTFTs are prone to converting the presence or change of target analytes into specific electrical signals even in complex biological systems. More importantly, OTFT sensors can be conveniently functionalized with chemical or biological modifications and exhibit substantially improved device sensitivity and selectivity as well as other analytical figure of merits, including calibration range, linearity, and accuracy. However, the stability and reproducibility of the organic devices need to be further improved. In this Account, we first introduce the unique features of OTFTs for bioelectronic applications. Two typical OTFT configurations, including organic electrochemical transistor (OECT) and electrolyte gated organic field effect transistor (EGOFET), are highlighted in their sensing applications mainly due to the operation of the devices in electrolytes and the combination of ionic and electronic charge transports in the devices. These devices are potentiometric transducers with low working voltages (<1 V) and high sensitivity, and are thus suitable for wearable applications with low power consumption. Second, the functionalization strategies on channel materials, electrolytes, and gate electrodes based on various modification methods and sensing mechanisms are discussed in sequence. In an OECT- or EGOFET-based biosensor, the device performance is particularly sensitive to the physical properties of the two interfaces, including channel/electrolyte and gate/electrolyte interfaces. Any change in the potential drop or capacitance of either interface can influence the channel current substantially. Therefore, the functionalization of the interfaces is critical to the sensing performance. In particular, when an electrochemically active material is modified on the interfaces, the reaction of the analyte catalyzed by the modified material can influence the interface potential and lead to a channel current response much stronger than that of a conventional electrochemical measurement. So the biosensors are much more sensitive than typical analytical methods due to the signal amplification of the transistors. Third, the processing techniques including screen printing and inkjet printing and the possibility for mass production are discussed. The applications of organic transistors in wearable electronics and healthcare monitoring systems, especially the fabric OECT-based biosensors for noninvasive detection, are presented. It is expected that the versatile organic transistors will enable various compact, flexible and disposable biosensors compatible with wearable electronics.
Graphene is the thinnest two-dimensional (2D) carbon material and has many advantages including high carrier mobilities and conductivity, high optical transparency, excellent mechanical flexibility ...and chemical stability, which make graphene an ideal material for various optoelectronic devices. The major applications of graphene in photovoltaic devices are for transparent electrodes and charge transport layers. Several other 2D materials have also shown advantages in charge transport and light absorption over traditional semiconductor materials used in photovoltaic devices. Great achievements in the applications of 2D materials in photovoltaic devices have been reported, yet numerous challenges still remain. For practical applications, the device performance should be further improved by optimizing the 2D material synthesis, film transfer, surface functionalization and chemical/physical doping processes. In this review, we will focus on the recent advances in the applications of graphene and other 2D materials in various photovoltaic devices, including organic solar cells, Schottky junction solar cells, dye-sensitized solar cells, quantum dot-sensitized solar cells, other inorganic solar cells, and perovskite solar cells, in terms of the functionalization techniques of the materials, the device design and the device performance. Finally, conclusions and an outlook for the future development of this field will be addressed.
2D materials have been successfully used in various types of solar cells as transparent electrodes, interfacial and active materials.
The studies of topological phases of matter have been developed from condensed matter physics to photonic systems, resulting in fascinating designs of robust photonic devices. Recently, higher-order ...topological insulators have been investigated as a novel topological phase of matter beyond the conventional bulk-boundary correspondence. Previous studies of higher-order topological insulators have been mainly focused on the topological multipole systems with negative coupling between lattice sites. Here we experimentally demonstrate that second-order topological insulating phases without negative coupling can be realized in two-dimensional dielectric photonic crystals. We visualize both one-dimensional topological edge states and zero-dimensional topological corner states by using the near-field scanning technique. Our findings open new research frontiers for photonic topological phases and provide a new mechanism for light manipulating in a hierarchical way.
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Microplastics (MPs) are ubiquitous in the environment, including the atmosphere. Yet, the size detection limit in measuring airborne MPs undermines the determination of the human MP ...exposure level through inhalation and also restricts the understanding of airborne MPs pollution behavior. To comprehensively and accurately assess the MPs pollution features in air, we demonstrate a qualitative and quantitively method using Raman microscopy to characterize the suspended atmospheric MPs. Our methodology has achieved detailed characterization of MPs down to 1 μm and ensured all the MPs to be counted regardless of their transparency. Further, a case study of indoor and outdoor samples from eight sampling sites were conducted in Shanghai, China. Inhalable MPs prevails in all samples with higher concentrations occur indoors. Indoor MPs varied strongly in composition compare to outdoor. Ventilation played an important role in lowering indoor MPs concentrations, and MPs in better ventilated indoors displayed similar distribution patterns as outdoors. MPs detected were mainly Polyethylene, Polyester, Phenolic Resin and Polyvinyl chloride. 77% of the Polyethylene detected were transparent films, suggesting the fragmentation from PE film products, such as plastic bags and cling films. Our work confirmed the widespread existences of inhalable MPs in air and provides solid foundations for future studies to understand the realistic MPs exposure conditions through inhalation.
Coronavirus disease 2019 (COVID‐19) remains a serious global threat. The metabolic analysis had been successfully applied in the efforts to uncover the pathological mechanisms and biomarkers of ...disease severity. Here we performed a quasi‐targeted metabolomic analysis on 56 COVID‐19 patients from Sierra Leone in western Africa, revealing the metabolomic profiles and the association with disease severity, which was confirmed by the targeted metabolomic analysis of 19 pairs of COVID‐19 patients. A meta‐analysis was performed on published metabolic data of COVID‐19 to verify our findings. Of the 596 identified metabolites, 58 showed significant differences between severe and nonsevere groups. The pathway enrichment of these differential metabolites revealed glutamine and glutamate metabolism as the most significant metabolic pathway (Impact = 0.5; −log10P = 1.959). Further targeted metabolic analysis revealed six metabolites with significant intergroup differences, with glutamine/glutamate ratio significantly associated with severe disease, negatively correlated with 10 clinical parameters and positively correlated with SPO2 (rs= 0.442, p = 0.005). Mini meta‐analysis indicated elevated glutamate was related to increased risk of COVID‐19 infection (pooled odd ratio OR = 2.02; 95% confidence interval CI: 1.17–3.50) and severe COVID‐19 (pooled OR = 2.28; 95% CI: 1.14–4.56). In contrast, elevated glutamine related to decreased risk of infection and severe COVID‐19, the pooled OR were 0.30 (95% CI: 0.20–0.44), and 0.44 (95% CI: 0.19–0.98), respectively. Glutamine and glutamate metabolism are associated with COVID‐19 severity in multiple populations, which might confer potential therapeutic target of COVID‐19, especially for severe patients.
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