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Cyclic CO2adsorption by using MgO as a sorbent at low temperatures is considered a promising route for postcombustion CO2capture. However, most MgO-based sorbents are in the form of fine powder and cannot be used in a fluidized bed reactor, and at the same time, suffer from a rapid loss in CO2uptake capacity due to the decrease of surface area aroused by pore shrinking and grain sintering. In this study, mesoporous silicas with highly ordered pore structures have been used as binders, for the first time, to fabricate MgO-based sorbent pellets via a simple and scalable extrusion–spheronization approach. The obtained MgO-based pellets exhibit high porosity attributed to the nature of the mesoporous binder, leading to a significantly increased stability and CO2uptake capacity. Especially for the low-concentration CO2that is comparable to the flue gas from a coal-fired power plant, the results show that the ordered mesoporous silica binder provides a remarkable promotion effect and excellent stability in the capture performance. The CO2uptake capacity of the best-performing sorbent, 20-KIT-6–100, displays a small decline of 6.86% (from 1.02 mmol of CO2/g in the first cycle to 0.95 mmol of CO2/g in the 10th cycle). It is envisaged that mesoporous materials hold great potential to be used as binders in reinforcing the metal oxide-based sorbents for flue-gas CO2capture in practical applications.

This article addresses the modeling and control of bioinspired cable-driven actuator that can mimic the three activation modes of human muscles. First, the dynamic model of the actuator is established by utilizing the coordinate transformation and kinetic energy theorem for controller and observer design. Then, a low-complexity output feedback controller with prescribed performance is proposed, so that the driving disc can track the rotation of the cable pulley without overshoot during the operation of the actuator. Specifically, the collision caused by overshoot during the tracking process must be avoided, as it can cause a sudden change of the cable tension, impact noise, and even mechanical parts damage. The presented low-complexity control strategy guarantees that the tracking error does not violate the predefined performance constraint and can converge to a predetermined residual set in finite time by introducing a novel error transformation function and a performance function. In addition, to avoid using angular velocity sensor, a finite-time observer with interval type-2 fuzzy system and adaptive technique is developed to estimate the angular speed of the driving disc. Finally, simulation studies and prototype experiments are performed to validate the effectiveness of the proposed control scheme on the bioinspired actuator.

Wearable electrical textiles are of great value for future personalized healthcare applications. Herein, we report a 3-D meshed textile pressure sensor, using a facile dip coating strategy, that combing the sensitive 2-D Ti3C2Tx MXene nanolayer with woven textile fibers. Based on the sensitive 3-D cross-connected conductive network, the textile sensor achieves simultaneously a high sensitivity of up to 81.9 kPa−1 and a fast response time of 30 ms in a wide pressure detection range (0–19 kPa) as well as prominent durability of more than 5000 cycles. Benefiting from superior performances, the textile sensor can be applied for real-time human physiological signals monitoring from pulse waves to human joint motion. This work represents a solid step toward personalized healthcare and clinical diagnosis.

Precise localization of checkerboard corner is crucial for camera calibration and accurate vision measurement. The accuracy of classical corner localization methods is affected by environmental factors, which hinders the effectiveness of vision measurements in complex scenes. We propose a novel end-to-end sub-pixel method for localizing checkerboard corners to overcome this challenge, demonstrating improved robustness in adverse conditions. We employ an EfficientNetv2-like backbone network to map the input image to a set of corners using offset regression. The continuous heatmap matching loss enables fine-grained spatial learning ability, while score loss ensures prediction sparsity and suppresses false positive probabilities. The model is trained on synthesized datasets with precise corner labels. Quantitative experimental results demonstrate the superior sub-pixel localization precision and robustness of our method on both synthetic and real-world datasets.

Wearable robotic devices interact with humans by applying the assistive force in parallel with muscle–tendon systems. Designing actuations in mimicking the natural activation patterns of human muscles is a promising way to optimize the performance of wearable robots. In this article, we propose a bioinspired cable-driven actuation system capable of providing anisometric contractions (including concentric and eccentric contraction) assistance or nearly acting as a transparent device in an efficient manner. A novel clutch–spring mechanism is employed to accomplish switches between assistive modes and the transparent mode. Corresponding control strategies coordinating with the mechanical design were presented and described in detail. Multiple evaluations were conducted on a test bench to characterize the system's performance. The closed-loop bandwidth of the system running concentric assistance control was 18.2 Hz. The R-squared values of linear fitting under eccentric assistance control were above 0.99. The engagement time of the proposed clutch was about 90 ms. Applying the actuation to an ankle exoskeleton, multiple walking experiments with electromyography measurements were performed on five subjects to show its application potential in existing wearable robots. Experimental results revealed that the proposed design could reduce soleus muscle activity by 27.32% compared with normal walking. This study highlights the importance of functional bionic design in human-assistance-related devices and introduces a general actuation system that could be directly applied to existing cable-driven wearable robots.

Knee exoskeletons have gained increasing attention for gait training and intervention. The effectiveness of conventional rigid exoskeletons is degraded by bulkiness, high inertia, and joint misalignment. The soft configurations relax the constraints on the knee joint, thus circumvent the misalignment issue, and reduce the system size and weight. However, the soft exoskeletons sacrifice the load sharing capability from rigid support, and also the mechanical stop for constraining joint working range to avoid unsafe knee hyperextension. This article presents a novel rigid-soft hybrid exoskeleton to provide bidirectional interventions safely for knee joint motion. The design is lightweight (1.2 kg to wear), avoids the rigid rotation center that induces knee joint misalignment, has minimal impact on normal walking kinematics, and is able to provide support to the human body. A gait intervention strategy is designed under the hybrid model of human and exoskeleton. Comprehensive experiments are conducted to demonstrate the capability of the presented exoskeleton on gait intervention.

In this article, an all-metal metamaterial absorber as a sensitive biosensor is proposed in the terahertz regime for biomolecular detection, such as protein, bacillus bacteria, and cancer cells. Here, the highly sensitive characteristic of the proposed absorber is implemented by the enhanced electromagnetic loss of symmetry-broken metal structures, where two discontinuous hollow rectangular metal arms are arranged orthogonally above the metal ground plane in geometry. Finite integral theory (FIT)-based software is utilized for modeling and full-wave numerical simulation. The results show that a near-perfect absorption of 100% at 1.99 THz is achieved with a quality factor value of 87, which could be an excellent performance in the terahertz regime below 2 THz. The electric and magnetic field distribution analysis is performed to reveal the mechanism, which is the significant confinement of electromagnetic field in the specially designed metal structure. The sensing performance of a refractive index is also investigated, and the resonance frequency and peak absorption of the spectra will get shift due to the variation of biological samples. The maximum sensitivity and figure of merit reach 540 GHz/RIU and 23.5 RIU−1, respectively. In addition, the effect of polarization angles and performance under different incident angles is also discussed. The presented biosensor with high sensitivity and feasible fabrication is a good candidate for biomedical detection in the terahertz regime.

Flexible sensors for high strain sensitivity and dynamic stability are important for the development of human-interactive and health-monitoring devices. However, establishing a stable conductive network with low-conductivity material filling that can resist tensile strain failure and achieve high device performance still faces significant challenges. Herein, a highly stretchable and sensitive strain sensor with strong dynamic stability and low conductive materials filling was fabricated based on highly conductive multi-walled carbon nanotubes (MWCNTs) and Fe nanowires (NWs) to construct a porous-designed bi-conducting network using a salt sacrificial template approach. The porous-designed Fe NW/MWCNT strain sensor (PFMS) with low material filling (3.6 wt.% Fe NWs and 10.6 wt.% MWCNTs) showed high sensitivity with a gauge factor (GF) of 134.98 (strain range 0–22%) and 569.37 (strain range 22%–60%), which is much higher compared with the pure MWCNT strain sensor with a GF of 7.46. This is attributed to the significant change in the contact area and contact resistance of the Fe NW/MWCNT bi-conducting network during tensile strain. In addition, the PFMS exhibited high repetitive stability over 2000 stretching-releasing cycles. When attached to the human body, the PFMS functions as a health-monitoring device, that can accurately distinguish human motions such as the bending of fingers, knees, and elbows. Finally, the proposed strategy pens a novel avenue for constructing porous conductive networks using polymer composites and is highly competitive for developing high-performance strain sensors.

This article presents a robotic trunk support system that provides dynamic support and direct force/moment measurement, to assist trunk movement and train related core muscle groups. The proposed system has four degrees of freedom, three in the coronal plane and one in flexion/extension motion, which has a larger range than the existing robotic braces. The system was designed based on the serial–parallel mechanism. The serial module is responsible for the flexion/extension motion, and the parallel module is responsible for three degrees of freedom in the coronal plane. The kinematic modeling and singularity analysis of the parallel mechanism were discussed in detail. Then, the position control and force control of the serial control actuator were implemented, and the experiments were carried out to evaluate the performance of the controller. The effects on human body in force control were discussed and explained. A reduction in anterior muscles activation and an increase of dorsal muscles activation were exhibited when flexion torque was applied, while the trunk core muscle groups have opposite activation when extension torque was applied. The results indicate that the proposed robotic brace has potentials in the application to trunk core muscle groups training and corresponding rehabilitation.

Purpose: To evaluate the biomechanics effect of modified cortical bone screw technique (MCBT) with other traditional internal fixation systems on lumbar osteoporotic wet specimen.Methods: Four different finite element models were established using CT data: (1) lumbar osteoporosis model without internal fixation system; (2) traditional pedicle screw technology (TT) model; (3) traditional cortical bone screw technology (CBT) model; (4) MCBT model. The changes of global displacement, intervertebral disc displacement of all models and internal fixation system Von Mises stress among the three models were compared under the same physiological load.Results: Compared with the other three models, the total displacement of the modified CBT screw model was the smallest, with the maximum displacement of 0.216 mm; The intervertebral disc displacement of the modified CBT screw model was the smallest, with the maximum displacement of 0.149 mm; the internal fixation system Von Mises stress of the modified CBT screw technique model was the largest compared with the other three models, The maximum Von Mises stress is 232.73 MPa.Conclusion: Compared to traditional pedicle screw and traditional CBT, MCBT has better mechanical stability, and it is of certain clinical application value.

Energy systems are currently undergoing a transformation towards new paradigms characterized by decarbonization, decentralization, democratization, and digitalization. In this evolving context, energy blockchain, aiming to enhance efficiency, transparency, and security, emerges as an integrated technological solution designed to address the diverse challenges in this field. Data security is essential for the reliable and efficient functioning of energy blockchain. The pressing need to address challenges related to secure data storage, effective data management, and efficient data utilization is increasingly vital. This paper offers a comprehensive survey of academic discourse on energy blockchain data security over the past five years, adopting an all-encompassing perspective that spans data storage, management, and utilization. Our work systematically evaluates and contrasts the strengths and weaknesses of various research methodologies. Additionally, this paper proposes an integrated hierarchical on-chain and off-chain security energy blockchain architecture, specifically designed to meet the complex security requirements of multi-blockchain business environments. Concludingly, this paper identifies key directions for future research, particularly in advancing the integration of storage, management, and utilization of energy blockchain data security.

Levitation by optical tweezers provides a unique non-invasive tool for investigating a microscale object without external perturbations. Here we experimentally levitate a micrometer-sized water droplet in the air using an optical tweezer. Meanwhile, vibrational modes of a levitated water droplet are excited by modulating the trapping laser. From their backscattered light, vibrational modes with mode numbers are observed in the spectra. Additionally, their corresponding free spectral ranges are analyzed and compared with theory and numerical simulations. This Letter, establishing a non-invasive and all-optical detection technique of optomechanical properties of levitated droplets, paves the way for their practical applications in aerosol and biomedical science.

A superconducting energy pipeline is an integrated system for fuel delivery and power transmission. In the energy pipeline, direct current (DC) power is carried by superconducting tapes with almost no loss. Moreover, liquefied natural gas (LNG) is used not only as one kind of clean energy but also as a cooling medium. However, the lack of data on the electrical insulation characteristics of LNG (especially the resistance to breakdown and flashover) restricts the development of a superconducting energy pipeline. Therefore, this paper focuses on solving a series of problems (such as gas tightness, overpressure, and high voltage) in LNG insulation testing, obtaining the electrical failure data of multicomponent LNG, and analyzing the behavior of electric breakdown and flashover in LNG. The test results show that LNG as a dielectric cooling medium has remarkable performance in withstand voltage to replace the liquid nitrogen/liquid tetrafluoromethane (LN2/LCF4) binary mixtures. The research could offer key technical support for the superconducting energy pipeline and also provide a reference for the study of electrical properties on other cryogenic fuels.

For the design of achromatic metalenses, one key challenge is to accurately realize the wavelength dependent phase profile. Because of the demand of tremendous simulations, traditional methods are laborious and time consuming. Here, a novel deep neural network (DNN) is proposed and applied to the achromatic metalens design, which turns complex design processes into regression tasks through fitting the target phase curves. During training, x−y projection pairs are put forward to solve the phase jump problem, and some additional phase curves are manually generated to optimize the DNN performance. To demonstrate the validity of our DNN, two achromatic metalenses in the near-infrared region are designed and simulated. Their average focal length shifts are 2.6% and 1.7%, while their average relative focusing efficiencies reach 59.18% and 77.88%.

Successful repair of long-distance peripheral nerve injuries remains a challenge in the clinic. Rapid axon growth is a key to accelerate nerve regeneration. Herein, a pure silk fibroin (SF) hydrogel with a combination of high-strength and aligned microgrooved topographic structure is reported. The hydrogels exhibit excellent mechanical properties with high strength. Good biocompatibility also allows the hydrogels to support cell survival. Significantly, the hydrogel with aligned microgrooved structures enables the aligned growth of Schwann cells. Moreover, the hydrogel holds a strong capacity for promoting axon growth and guiding neurite sprouting. Thus, this micropatterned SF hydrogel would have great potential for peripheral nerve regeneration.

DNA molecules are hard to catch using traditional optical trapping due to the nanometer width of their chains. Here we experimentally demonstrate a label-free optical trapping of a single micrometer λ-DNA in solution by the aid of plasmonic gold nanoparticles (GNPs), where a double-laser trap induces strong optical interparticle forces for the tweezer. We examine such sub-resolved interparticle forces by tracking the GNP dynamics in solution. Moreover, surface-enhanced Raman scattering signals of trapped λ-DNA have also been measured simultaneously in the same setup. In comparison with prior works, ours benefit from the excitation in a dynamic configuration without fabrication. This technique opens a new avenue for all-optical manipulation of biomolecules, as well as ultra-sensitive bio-medical sensing applications.

To achieve high-performance flexible pressure sensors, it is imperative to develop biomimetic devices that mimic the functional structure and sensing mechanism of human skin. Nevertheless, the creation of skin-like sensors with both ultra-high sensitivity and broad response range poses a formidable challenge. Drawing inspiration from the tactile sensing mechanisms and hierarchical structure of human skin, we engineered a nanofiber-iongel (NFIG) composite with internally graded stiffness characteristics and surface semi-embedded microstructures through the application of electrostatic spinning and droplet injection methods. The gel mimics the layered nanofiber structure of human skin, along with its ion-sensing mechanism, and comprises an ion gel infused with highly elastic PVDF-HFP nanofibers. This study explores the impact of Young's modulus and external pressure on unit capacitance, and it establishes a fiber-gel composite model to assess how the fibers influence sensor performance, encompassing ion fluxes, displacements, and alterations in electric potential. These findings reveal that the utilization of high-modulus materials enhances ion mobility, decreases the double electrical layer thickness, and augments pressure resistance. Based on these discoveries, we engineered the NFIG sensor, which exhibits ultra-high sensitivity (>10,000 kPa−1), a wide pressure range (∼1000 kPa), and exceptional stability (over 5000 cycles). Furthermore, this sensor is versatile, finding utility in a range of human monitoring contexts, array configurations, and even skateboard monitoring, thereby substantiating its promise in the fields of human-computer interaction and sports health.

Footfall contains the highest harvestable biomechanical energy from the human body, which can attain 67 W, showing great potential as a pervasive and sustainable power source for wearable bioelectronics in the era of the Internet of Things. Developing an effective technology for robust and efficient energy harvesting from human walking remains highly desired. Here, we present a waterproof smart insole, based on a triboelectric nanogenerator, for highly efficient and robust human biomechanical energy harvesting. This insole was rationally designed as a composite structure to fully utilize the pressure distribution of a footfall for wearable electricity generation and to deliver a power output reaching 580 μW. The insole was additionally able to withstand use in harsh environments, including pluvial conditions, without affecting the power output consistency. A total of 260 light-emitting diodes were lit up with perspiring feet and water on the floor, and a capacitor of 88 μF was charged to 2.5 V in 900 s. This work represents a practical approach to developing a highly efficient and robust smart insole that can be used as a sustainable power source for wearable bioelectronics.

Laser scanning photothermal imaging offers a powerful non-destructive testing tool to visualize subsurface structures of opaque materials, but it suffers the resolution limit imposed by thermal diffusion. To overcome this physical obstacle, a tightly focused excitation beam with a high repetition rate is usually used to improve the spatial resolution. Here, we demonstrate that the resolution of photothermal imaging could be enhanced using the high-order correlation imaging method inspired by correlated optical imaging. By carefully designing the laser scanning and modulation behavior, we can individually control the statistical properties of isolated hotspots induced by lasers. Imaging reconstructions of subsurface structures are performed afterward by reading out time-fluctuated thermal images. Moreover, the resolution can be further enhanced by using the high-order correlation, which enables a new way for highly resolved thermal imaging and metrology applications.

Long persistent phosphors (LPPs) with ultraviolet (UV) luminescence have great potential for application in the fields of biomedicine, environmental, and catalysis. However, it is currently limited by the design and development of remarkable UV LPPs with a suitable spectral region and an ultralong afterglow decay time. Herein, we develop a new type of Bi3+-activated LiScGeO4LPP, which exhibits bright ultraviolet-A (UVA) persistent luminescence (PersL). Because of the existence of numerous stabilized effective traps, the as-synthesized phosphors can undergo an ultralong PersL decay time far longer than 12 h. The PersL properties, effective trap depths, distributions, and types, as well as the possible mechanism for the PersL behavior of LiScGeO4:Bi3+, are comprehensively surveyed utilizing PersL excitation spectra, PersL decay analyses, thermoluminescence experiments, and X-ray photoelectron spectroscopy. This work can cover the shortage of LPPs in the UV region and also can lay the foundation for the development of more excellent UV LPPs toward versatile novel applications.

This paper presents a wakeup timer in 40-nm CMOS for Internet-of-Things (IoT) applications based on a bang-bang Digital-intensive Frequency-Locked Loop (DFLL). A self-biased $\Sigma \Delta $ Digitally Controlled Oscillator (DCO) is locked to an RC time constant via a feedback loop consisting of a single-bit chopped comparator and a digital loop filter, thus maximizing the use of digital circuits while keeping only the RC network and the comparator as the sole analog blocks. Analysis and behavior level simulations of the DFLL have been carried out to guide the optimization of the long-term stability and frequency accuracy of the timer. High frequency accuracy and a $10\times $ enhancement of long-term stability is achieved by the adoption of chopping to reduce the effect of comparator offset and 1/f noise and by the use of $\Sigma \Delta $ modulation to improve the DCO resolution. Such highly digitized architecture fully exploits the advantages of advanced CMOS processes, thus enabling operation down to 0.7 V and a small area (0.07 mm2). The proposed timer achieves the excellent energy efficiency (0.57 pJ/cycle at 417 kHz at 0.8-V supply) over prior art while keeping excellent on-par long-term stability (Allan deviation floor < 20 ppm) and temperature stability (33 ppm°Cat 0.8-V supply). [ABSTRACT FROM AUTHOR]

Internet-connected clothing/textiles is a promising but underexplored option for future personalized health care. Here, we report a textile-based sensor (TS) system with art design for wearable biomonitoring and interacting over the Internet. The TS is capable of delivering a sensitivity up to 3.88 V/kPa for ambient tiny pressure sensing. Made of durable materials, the TS exhibits remarkable robustness after more than 80,000 cycles of continuous operation. A wireless biomonitoring system (WBS) has been developed for timely processing of the acquired human pulse wave signals, wirelessly transmitting and displaying the patient’s health data via an APP interface onto a smartphone. The WBS was used to effectively diagnose obstructive sleep apnea-hypopnea syndrome during a whole night of sleep even with body movements. The textile-based wireless biomonitoring system represents a solid step toward constructing a body area network for personalized health care in the era of the Internet of Things.

Two-dimensional Bi2Te3nanosheets (NSs) have recently been validated as a new type of photothermal agent to provide an alternative option for tumor ablation vialight-induced hyperthermia. However, the surface of Bi2Te3NSs lacks active radicals for the conjugation of functional molecules, which undoubtedly impedes their versatile utilization in medical areas. Here, the surface activation of Bi2Te3NSs was accomplished viathe in situgrowth of an SiO2nanoshell assisted by tetraethyl orthosilicate (TEOS). Upon the co-condensation of (3-aminopropyl)triethoxysilane (ATPES), terminal amino groups (–NH2) were generated on the surface of the Bi2Te3@SiO2NSs, which were further covalently coupled with the photosensitizer chlorin e6 (Ce6) through a standard amide reaction. The resultant Bi2Te3@SiO2/Ce6 (BSC) NSs displayed admirable photothermal properties, a high Ce6 loading capacity, and good biocompatibility. Upon dual-wavelength laser irradiation, an excellent tumor suppression effect arising from thermal ablation and reactive oxygen species (ROS)-induced apoptosis was verified both in cell experiments and in animal studies. In addition, synchronous fluorescence/photoacoustic/infrared (FL/PA/IR) tri-modal imaging could provide useful information for both tumor diagnosis and prognosis. Overall, this facile strategy for the activation of Bi2Te3is regarded to be universal for the development of more versatile Bi2Te3-based nanoplatforms, which should favor the rapid diagnosis and effective treatment of fatal diseases.

The fingertip-pulse waveform carries abundant information regarding human physiological condition that is fundamental for directly extracting physiological parameters. Making the surfaces of ordinary objects that are often in contact with fingertips, such as tables and computers, capable of perceiving dynamic epidermal pulse signals has great significance for accurately assessing health conditions without restrictions on time and place. Here, we demonstrate the materials and design of a nanohemispherical pressure sensor that can be attached to ubiquitous objects’ surfaces to monitor fingertip pulse. The portable sensor achieved an ultrasensitivity of 49.8 mV/Pa, a prominent response time of less than 6 ms, and long-term durability of more than 4 months. As demonstrated, the sensor is utilized to measure subtle fingertip-pulse waves and extract characteristic points of the waveform on the surface of keyboards, mobile phones, and human skin. Given the superior performance of the sensor, a real-time, wireless arteriosclerosis monitoring system is developed. By analyzing the characteristic parameters of the pulse waveforms measured from 54 volunteer participants, the antidiastole of arteriosclerosis could be instructively diagnosed. The sensor proposed in this work is expected to be a competitive alternative to current complicated medical equipment and to be extensively applied in wireless cardiovascular monitoring systems.

Human-machine interfaces enable the exchange of information between people and machines, which plays a crucial role in artificial intelligence. In this field, sensors based on magnetism, electricity, mechanics, and optics are used to construct interactive interfaces and have an important role in sensing human behavior. Here, we present a vibration sensor based human-machine interface (HMI) with an unlimited sensing area on a ubiquitous surface by detecting and positioning an external vibration source. To accurately perceive an external minute vibration, we proposed triboelectric vibration sensors (TVS) designed by mimicking the ampulla in the lateral line of a fish. Imitating the cilia wrapped in the ampulla structure, the tribo-pair of TVS were designed as nanowire arrays and hemispherical pore structures. It achieved a high force sensitivity of 0.97 V/N when the force is less than 1 N and a broad frequency range from 1 to 3 kHz. Given the excellent performance of the TVS, an in-plane vibration source detection and location system was developed, which utilizes the time difference in the arrival estimation method based on correlation analysis. As a demonstration, a TVS-based intelligent virtual digital keyboard was developed by sensing and locating the position of the keystroke for interactive input and importer authentication according to the bionic features. Furthermore, a customized multifunctional desktop interactive system was established by functionalizing an ordinary table for convenient electrical appliance control. In this way, ordinary surfaces such as tables, walls, and doors have the potential to be converted into multifunctional interactive interfaces. The proposed TVS-based HMI in this work can be immediately and extensively adopted in a variety of applications for portable computer peripherals, cyber security, and intelligent home systems.

To date, male infertility has become a critical global health problem in contemporary society, which adversely impacts human natural reproduction and social development. Moreover, male infertility is generally associated with an inadequate concentration, low motility and a high abnormity rate of sperms. However, although current medical tests have achieved significant progress in quantifying sperm count and normal sperm density, point-of-care testing (POCT) devices are still urgently needed for more rapid, effective and accurate diagnoses, which can also overcome the drawbacks of expensive examination and concerns related to the disclosure of patient privacy for clinical testing. Recently, microfluidic chips for sperm inspection, which feature greater convenience, low cost, a tiny sample volume, high-throughput and scale-up production, have attracted increasing attention in the field of auxiliary medical devices for assessing sperm quality and quantity. Herein, we systematically review the most prevalently used analytical strategies towards sperm inspection in recent years. Future prospects for the development of sperm diagnostic devices were put forward to facilitate their commercialization for maximizing the benefits of both patients and providers.

Reusing waste materials to create energy harvester will not just reduce the environmental pollution, but also generate renewable electricity by scavenging environmental energy to power wireless electronic devices, which will make our life more environmental friendly. In this study, we first turn waste milk carton into fully packaged arc-shaped triboelectric nanogenerator (AS-TENG) which can scavenge both wind and water flow energy for long-term wireless environmental monitoring. In general, the milk carton is laminated (from inside out) with a layer of polyethylene (PE), a layer of aluminum (Al) foil and a pulp layer. Such laminated material is suitable as the electrical unit of the AS-TENG. The arc-shaped design of AS-TENG is implemented to disrupt the flow, leading to vortex induced vibration, and thus contact electrification of the AS-TENG results in power generation. By optimizing the structural parameters systematically, the AS-TENG achieves an instantaneous peak voltage of 600 V, and a current of 40 μA. Moreover, a self-powered wireless environmental monitoring system using AS-TENG as power supply is developed for in-situ real time water quality (pH value) monitoring and landslide early warning in natural environment. This study provides solid progress toward the practical applications of TENGs in environmental monitoring.

Heart-rate monitoring plays a critical role in personal healthcare management. A low-cost, noninvasive, and user-friendly heart-rate monitoring system is highly desirable. Here, a self-powered wireless body sensor network (BSN) system is developed for heart-rate monitoring viaintegration of a downy-structure-based triboelectric nanogenerator (D-TENG), a power management circuit, a heart-rate sensor, a signal processing unit, and Bluetooth module for wireless data transmission. By converting the inertia energy of human walking into electric power, a maximum power of 2.28 mW with total conversion efficiency of 57.9% was delivered at low operation frequency, which is capable of immediately and sustainably driving the highly integrated BSN system. The acquired heart-rate signal by the sensor would be processed in the signal process circuit, sent to an external device viathe Bluetooth module, and displayed on a personal cell phone in a real-time manner. Moreover, by combining a TENG-based generator and a TENG-based sensor, an all-TENG-based wireless BSN system was developed, realizing continuous and self-powered heart-rate monitoring. This work presents a potential method for personal heart-rate monitoring, featured as being self-powered, cost-effective, noninvasive, and user-friendly.

Ever since its establishment, tremendous developments in chemical looping technology have been taking place not only for its capability of highly efficient CO2capture during fuel combustion but also for its flexibility in fuel conversion and CO2utilization. Given the global urgency in mitigating the greenhouse effect, the chemical looping CH4conversion coupled with CO2utilization, more recently, has become a new focus owing to its effectiveness in co-converting the two most abundant anthropogenic greenhouse gases. This review highlights the latest advances in chemical looping CH4conversion coupled with CO2utilization, and the scope of chemical looping technologies here can be defined as chemical looping reforming, chemical looping CO2splitting, and calcium looping. Special attention has been paid to the concept design and selection of suitable looping materials. Meanwhile, the remaining challenges and future research directions have been outlooked.

Incineration is widely applied in municipal solid waste treatment and energy recovery, especially in China. The efficiency of energy recovery does not only depend on the design and construction of equipment, but it is also highly affected by the operation. Primary air temperature is a key parameter for incinerator operation, but there is still limited information about how primary air temperature affects MSW incineration. Fluid dynamic incinerator code (FLIC) and Fluent coupled model was used to study the influence of different primary air temperatures on MSW incineration in a moving grate incinerator with five zones of primary air feeding. Four different conditions were investigated and compared, namely, control case (20 °C for five grate zones), case 180 (180 °C for five grate zones), case I (190 °C for two front zones, and 180 °C for three behind zones) and case II (190 °C for two front zones, 170 °C for two middle zones, 160 °C for the last zone). The result demonstrated, as the air preheating temperature increased, so did the rate of moisture evaporation and volatile release, the latter of which could potentially lead to higher local maximum temperature in the furnace. It was possible, by using the different primary air temperature setup, to maintain a relatively high rate of moisture evaporation and total mass loss, while having a lower rate of volatile release. Ultimately, the multi-temperature primary air setup maintained a high time-average rate evaporation of moisture at 0.04230518 kg/m2s, and lowers the time-averaged rate of volatile release to 0.0396193 kg/m2s, thus, maintained the local maximum furnace temperature at 1685 °C. This concept can potentially be utilized in MSW incinerators to effectively evaporate moisture from MSW while keeping the local maximum temperature in the furnace to a reasonable temperature.

Hazardous waste incineration fly ash (HFA) is high risk for the environment due to heavy metals leaching and other pollutants. Sintering treatment potentially reduces the mass and volume of HFA and immobilizes heavy metals in ceramic-like bodies. However, HFA contains a large amount of heavy metals, thus sintering at too high a temperature will lead to the volatilization of heavy metals. The low-temperature sintering behavior of HFA at different temperature (450 °C, 670 °C and 900 °C) and different atmospheres (21% O2, 47.3% O2, 60.5% O2and 100% O2) was investigated in this study. The mass loss, morphology, bulk density, elemental composition, heavy metal leaching rate, and mineral phase transformation of sintered ash were experimentally tested. With increasing sintering temperature, more mass of HFA was lost and the leaching rate of heavy metals decreased. For instance, sintered at 450 °C, 670 °C and 900 °C under air, the mass losses were 4.30%, 6.58%, and 17.96%, the leaching rate of Pb were 19.37%, 2.74%, and 0.65%, respectively. Sintered ash became denser and formed ceramic-like particle due to thermal agglomeration and chemical reactions. The bulk density significantly increased, which was favorable to reduce space occupancy for fly ash landfill. Oxygen-rich atmosphere could make the fly ash denser and inhibit the volatilization and leaching of Pb. The obtained findings are beneficial for deep understanding of the sintering behavior of HFA at low-temperature.

With the development of the Internet of Things (IoT), the requirement of wireless sensing operations is becoming increasingly desirable. Most of the current active wireless sensors require external power suppliers and complex active circuits, which limits their applications. A passive wireless sensor is a desired alternative. Hence, a passive wireless triboelectric sensor (PWTES) without active electronic components, a battery, or an energy harvester is proposed to meet the further demand for wireless monitoring. The key component of the PWTES is a surface acoustic wave resonator (SAWR). The sensing signal generated by the triboelectric nanogenerator (TENG) is applied to modulate the SAWR's response signal via a tuning network. A designed reader interrogates the SAWR and receives its response via the radiofrequency link, then demodulation is performed on the SAWR's response to obtain the sensing signal. Employing the designed PWTES, a wireless pressure sensor without a battery and an energy harvester is successfully demonstrated. The PWTES exhibited the wireless transmission of a sensing signal over a distance of 2 m, a sensitivity of 23.75 kHz/V within the TENG's voltage range of 0–5 V, and a measurement update rate of 12 kHz. The PWTES makes full use of the advantages of the TENG in sensing, and the properties of the SAWR in wireless communication, holding great potential for the miniaturization, integration, and continuous monitoring of wireless sensors in the era of the IoT.