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A three-dimensional liquid diode has been developed to transport sweat and create breathable bioelectronics. The utilization of hydrophilic and curvature gradients facilitates water lifting, enhancing the adhesion time and signal stability of biosensors. Its waterproof nature enables the detection of trace-level biomarkers and integration with wearable monitoring systems.

Brownian motion allows microscopically dispersed nanoparticles to be stable in ferrofluids, as well as causes magnetization relaxation and prohibits permanent magnetism. Here we decoupled the particle Brownian motion from colloidal stability to achieve a permanent fluidic magnet with high magnetization, flowability and reconfigurability. The key to create such permanent fluidic magnets is to maintain a stable magnetic colloidal fluid by using non-Brownian magnetic particles to self-assemble a three-dimensional oriented and ramified magnetic network structure in the carrier fluid. This structure has high coercivity and permanent magnetization, with long-term magnetization stability. We establish a scaling theory model to decipher the permanent fluid magnet formation criteria and formulate a general assembly guideline. Further, we develop injectable and retrievable permanent-fluidic-magnet-based liquid bioelectronics for highly sensitive, self-powered wireless cardiovascular monitoring. Overall, our findings highlight the potential of permanent fluidic magnets as an ultrasoft material for liquid devices and systems, from bioelectronics to robotics.

Due to the lack of mechanical bearing support for the dual-winding bearingless flux-switching permanent magnet machine (BFSPMM), it is necessary to constantly detect the radial position information of the rotor through the sensor, which has some disadvantages such as high cost and complex installation process. In this article, a novel rotor radial position observation method is proposed to overcome the above shortcomings. First, the working principle of motor rotation and suspension is analyzed, and the characteristics of back EMF and permanent magnet flux linkage with rotor eccentricity in suspension winding are discussed. Second, according to the magnetic field modulation theory, the relation between the coupled permanent magnet flux linkage in the suspension coils and the eccentric displacement of the rotor is derived, and the mathematical model of rotor radial position observation is established. Then, the coupling permanent magnet flux linkage of suspension winding is extracted through the voltage model method, and the error of rotor radial position observation is indirectly compensated. Finally, the experiment verifies that the proposed method can effectively detect the rotor radial position information.

Vibration is a common, usually wasted energy, and an attractive target for sustainable electricity generation. In this work, we introduce a new working mechanism to the vibration energy harvesting community by contributing a spherical magnetoelastic generator (S-MEG), which permits multidirectional vibration and is highly adaptable to many natural oscillation frequencies, exhibiting a resonant frequency of 24 Hz and a relatively wide working bandwidth of 15 Hz in the low-frequency range. It also features a low internal impedance of 70 Ω, which can respectively deliver a maximum short-circuit current density of 7.962 A·m–2and a power density of 15.1 mW·m–2. To demonstrate the capability of S-MEG for ambient vibration energy harvesting, a 220 μF commercial capacitor was successfully charged to 2 V within 25 s, sustainably driving wearable bioelectronics for multiple physiological information monitoring. It could also harvest multidirectional vibration energy from both hand-shaking and bicycle-riding, generating approximately 2.5 mA and 6 mA alternating current from the motions, respectively, even with heavy perspiration or on a rainy day without the need for encapsulation. In summary, this work brings forth an appealing platform technology to the community of vibration energy harvesting, holding a collection of compelling features, including high current density, low inner impedance, intrinsic waterproofness, and scalability for large-scale vibration energy harvesting.

A silicone encapsulation of an array of vibrating motors serves as a conformal haptic interface that delivers vibrational feedback to the user. The development of haptic interfaces providing tactile feedback opens another sensory channel allowing human interaction with machines through the sensation of touch.

Dr. Jun Chen is currently an assistant professor in the Department of Bioengineering at the University of California, Los Angeles. His current research focuses on nanotechnology and bioelectronics for energy, sensing, and therapeutic applications in the form of smart textiles, wearables, and body area networks. With a current h-index of 85, he has published 2 books, 1 book chapter, and 230 journal articles, 130 in which he is a corresponding author, in Chemical Reviews, Chemical Society Reviews, Nature Materials, Nature Electronics, Nature Communications, Science Advances, Joule, Matter, and more. Among his many accolades are the Fellow of International Association of Advanced Materials, ACS PMSE Young Investigator Award, UCLA Society of Hellman Fellows Award, Okawa Foundation Research Award, Advanced Materials Rising Star, Materials Today Rising Star Award, ACS Nano Rising Stars Lectureship Award, Chem. Soc. Rev. Emerging Investigator Award, and many others. Beyond research, he is an associate editor of Biosensors and Bioelectronics.

Interfacing with the human body, wearable and implantable bioelectronics are a compelling platform technology for healthcare monitoring and medical therapeutics. However, clinical adoption of these devices is largely shadowed by their weakness in humidity resistance, stretchability, durability, and biocompatibility. In this work, we report a self-powered waterproof biomechanical sensor with stretchability up to 440% using the giant magnetoelastic effect in a soft polymer system. By manipulating the magnetic dipole alignment, the sensor achieved a particularly broad sensing range from 3.5 Pa to 2000 kPa, with a response time of ∼3 ms. To validate the excellent performance of the magnetoelastic sensor in biomonitoring, both ex vivoporcine heart testing and in vivorat model testing were performed for cardiovascular monitoring and heart disease diagnosis. With the obtained sensing data, we have successfully detected ventricular arrhythmia and ventricular fibrillation in the Sprague–Dawley rat model. Holding a collection of compelling features, including minimal hysteresis, ultrawide sensing range, waterproofness, and biocompatibility, the magnetoelastic sensor represents a unique platform technology for self-powered biomonitoring in both wearable and implantable manners.

The high moisture level of exhaled gases unavoidably limits the sensitivity of breath analysis via wearable bioelectronics. Inspired by pulmonary lobe expansion/contraction observed during respiration, a respiration-driven triboelectric sensor (RTS) was devised for simultaneous respiratory biomechanical monitoring and exhaled acetone concentration analysis. A tin oxide-doped polyethyleneimine membrane was devised to play a dual role as both a triboelectric layer and an acetone sensing material. The prepared RTS exhibited excellent ability in measuring respiratory flow rate (2–8 L/min) and breath frequency (0.33–0.8 Hz). Furthermore, the RTS presented good performance in biochemical acetone sensing (2–10 ppm range at high moisture levels), which was validated via finite element analysis. This work has led to the development of a novel real-time active respiratory monitoring system and strengthened triboelectric–chemisorption coupling sensing mechanism.

We discovered a giant magnetoelasticity in soft matter with up to 5-fold enhancement of magnetomechanical coupling factors compared to that of rigid metal alloys without an externally applied magnetic field. A wavy chain analytical model based on the magnetic dipole-dipole interaction and demagnetizing field was established, fitting well to the experimental observation. To explore its potentials in electronic textiles, we coupled it with magnetic induction to invent a textile magnetoelastic generator (MEG), a new working mechanism for biomechanical energy conversion, featuring an intrinsic waterproofness, an ultralow internal impedance of approximately 20 Ω, and a high short-circuit current density of 1.37 mA/cm2, which is about four orders of magnitude higher than that of other textile generator counterparts. Meanwhile, assisted by machine learning, the textile MEG could continuously monitor the respiratory activities on heavily perspiring skin without any encapsulation, allowing a timely diagnosis of the respiration abnormalities in a self-powered manner. We foresee that this discovery can be extended to wide-range soft-matter systems, emerging as a compelling approach to develop electronic textiles for energy, sensing, and therapeutic applications.

Tunable gating graphene oxide (GO) membranes with high water permeance and precise molecular separation remain highly desired in smart nanofiltration devices. Herein, bioinspired by the filtration function of the renal glomerulus, we report a smart and high-performance graphene oxide membrane constructed viaintroducing positively charged polyethylenimine-grafted GO (GO-PEI) to negatively charged GO nanosheets. It was found that the additional GO-PEI component changed the surface charge, improved the hydrophilicity, and enlarged the nanochannels. The glomerulus-inspired graphene oxide membrane (G-GOM) shows a water permeance up to 88.57 L m–2h–1bar–1, corresponding to a 4 times enhancement compared with that of a conventional GO membrane due to the enlarged confined nanochannels. Meanwhile, owing to the electrostatic interaction, it can selectively remove positively charged methylene blue at pH 12 and negatively charged methyl orange at pH 2, with a removal rate of over 96%. The high and cyclic water permeance and highly selective organic removal performance can be attributed to the synergic effect of controlled nanochannel size and tunable electrostatic interaction in responding to the environmental pH. This strategy provides insight into designing pH-responsive gating membranes with tunable selectivity, representing a great advancement in smart nanofiltration with a wide range of applications.

Herein, an efficient strategy to fabricate well-organized one-dimensional (1D) inorganic nanostructures is demonstrated by utilizing the hollow tobacco mosaic virus coat protein (TMVCP) as a restrictive template. Considering the advantages of the unique hollow structure and the dynamic self-assembly attribute of TMVCP, foreign nano-objects are successfully encapsulated and conveniently assembled into highly organized 1D chainlike structures in the cavity of the TMVCP multimer (TMV disk). Different kinds of functional nanoparticles, such as gold nanoparticles (AuNPs) and silver sulfide quantum dots (Ag2S QDs), are used to demonstrate the successful construction of ordered 1D nanochains in high yields. Notably, binary nanochains of such different kinds of nanoparticles are also constructed through co-assembling the TMV disk-coated AuNPs and Ag2S QDs. Further, the TMV-assisted AuNP nanochains are grown into the 1D nanowires through in situAu deposition owing to the spatial confinement of the TMVCP cavity. Together, our findings indicate that the TMV-assisted self-assembly approach, resulting in higher yields and better controllability over the other reported studies based on directly mineralizing the metal architectures in the TMV nanorods, provides enormous potential toward the fabrication of highly complex hybrid-metal nanostructures.

The magnetoelastic effect—the variation of the magnetic properties of a material under mechanical stress—is usually observed in rigid alloys, whose mechanical modulus is significantly different from that of human tissues, thus limiting their use in bioelectronics applications. Here, we observed a giant magnetoelastic effect in a soft system based on micromagnets dispersed in a silicone matrix, reaching a magnetomechanical coupling factor indicating up to four times more enhancement than in rigid counterparts. The results are interpreted using a wavy chain model, showing how mechanical stress changes the micromagnets’ spacing and dipole alignment, thus altering the magnetic field generated by the composite. Combined with liquid-metal coils patterned on polydimethylsiloxane working as a magnetic induction layer, the soft magnetoelastic composite is used for stretchable and water-resistant magnetoelastic generators adhering conformably to human skin. Such devices can be used as wearable or implantable power generators and biomedical sensors, opening alternative avenues for human-body-centred applications.

The triboelectric nanogenerator (TENG) has been proved to be a green and efficient energy harnessing technology for electricity generation from ambient mechanical motions based on its ability to leverage the triboelectrification process. Enhancing TENG output performance through rational structural design still triggers increasing research interest. Here, we report a ternary electrification layered architecture beyond the current binary TENG systems, with improved performance for mechanical energy harvesting. Introducing a ternary Kapton layer into the traditional binary electrification layered architecture of TENGs consisting of copper and fluorinated ethylene propylene, yields a 2.5 times enhancement of peak power output, representing a 6.29-fold increase compared to the TENG composed of copper and Kapton. A wide-range of material configurations were systematically tested using this ternary electrification layered architecture to prove its practical effectiveness. The ternary electrification layered architecture invented in this work provides an alternative strategy to enhance TENG output performance, which represents a solid step for TENGs application in high-performance mechanical energy harvesting.

Fossil fuel internal combustion engines generate and release a huge amount of nitrogen dioxide, leading to respiratory and allergic diseases such as asthma, pneumonia, and possibly tuberculosis. Here we develop an alveolus-inspired membrane sensor (AIMS) for self-powered wearable nitrogen dioxide detection and personal physiological assessment. The bionic AIMS exhibits an excellent sensitivity up to 452.44%, a good linearity of 0.976, and superior selectivity under a NO2concentration of 50 ppm. Furthermore, the AIMS can also be employed to diagnose human breath behaviors for breath analysis. The fundamental sensing mechanism is established using a combination of thermodynamic analysis, finite-element analysis, and phase-field simulations. It is found that the depolarization field inside the sensitive materials plays a crucial role in the self-powered gas-sensing performance. This work not only provides an efficient, low-cost, portable, and environmentally friendly means for active environmental assessment and personal biomonitoring but also provides a deep understanding of the gas-sensing mechanisms.

Stretchable supercapacitors based on vertically aligned nanotubes or nanowires have attracted considerable attention because of their improved robustness and electrochemical performance under large and repeated deformations. Here, we demonstrate a robust and high-performance stretchable electrode based on crumpled Au-coated carbon nanotube forest (Au-CNT forest). Experimental measurements show that the resistance of the Au-CNT forest electrode is around one order magnitude lower than that of a pure CNT forest electrode. The biaxially crumpled Au-CNT forest electrode demonstrates nearly identical electrochemical performance at different measured charge/discharge rates under different strain conditions (i.e., from 0% to 800% area strain). The as-prepared symmetric supercapacitor demonstrates a maximum specific capacitance of ∼6 mF cm−2at the current density of 40 mA cm−2under large strains, exhibiting superior mechanical and electrochemical stability. This research presents a facile process to fabricate highly stretchable supercapacitors based on vertically aligned nanotubes or nanowires for achieving exceptional and robust electrochemical performance.

Smart textiles for electricity generation are a superior energy solution with greatly improved convenience and comfort for wearable bioelectronics. However, maintaining the sustainability and stability of the power supply, though highly desirable, remains a great challenge. Here, we present a photo-rechargeable fabric with economically viable materials and scalable fabrication technologies. The fabric was able to constantly deliver electric power for 10 min at 0.1 mA after being charged for 1 min under the standard 1-sun condition. It can also work normally under twisted and watery circumstances and hold the stored energy for over 60 days without significant voltage loss. The photo-rechargeable fabric was demonstrated to power a body area sensor network for personalized healthcare.

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.

Biomolecular assembly in biological systems is typically a complex dynamic process regulated by the exchange of molecular information between biomolecules such as proteins and nucleic acids. Here, we demonstrate a nucleic-acid-based system that can program the dynamic assembly process of viral proteins. Tobacco mosaic virus (TMV) genome-mimicking RNA is anchored on DNA origami nanostructures via hybridization with a series of DNA strands which also function as locks that prevent the packaging of RNA by the TMV proteins. The selective, sequential releasing of the RNA via toehold-mediated strand displacement allows us to program the availability of RNA and subsequently the TMV growth in situ. Furthermore, the programmable dynamic assembly of TMV on DNA templates also enables the production of new DNA–protein hybrid nanostructures, which are not attainable by using previous assembly methods.

The development of stretchable electronics requires the invention of compatible high-performance power sources, such as stretchable supercapacitors and batteries. In this work, two-dimensional (2D) titanium carbide (Ti3C2Tx) MXene is being explored for flexible and printed energy storage devices by fabrication of a robust, stretchable high-performance supercapacitor with reduced graphene oxide (RGO) to create a composite electrode. The Ti3C2Tx/RGO composite electrode combines the superior electrochemical and mechanical properties of Ti3C2Txand the mechanical robustness of RGO resulting from strong nanosheet interactions, larger nanoflake size, and mechanical flexibility. It is found that the Ti3C2Tx/RGO composite electrodes with 50 wt % RGO incorporated prove to mitigate cracks generated under large strains. The composite electrodes exhibit a large capacitance of 49 mF/cm2(∼490 F/cm3and ∼140 F/g) and good electrochemical and mechanical stability when subjected to cyclic uniaxial (300%) or biaxial (200% × 200%) strains. The as-assembled symmetric supercapacitor demonstrates a specific capacitance of 18.6 mF/cm2(∼90 F/cm3and ∼29 F/g) and a stretchability of up to 300%. The developed approach offers an alternative strategy to fabricate stretchable MXene-based energy storage devices and can be extended to other members of the large MXene family.

Heteroatom-functionalized porous carbon has long been regarded as a promising electrode material to construct high-performance capacitive energy storage devices. However, the development of this field is seriously limited due to the lack of an in-depth understanding of the ion-sorption dynamics. Herein, the component and structure controllable N, O, and Cl codoped bimodal (micro-to-meso) porous carbons were prepared and further used as the investigated object for exploring the intrinsic ion-sorption dynamics, which is the root of the enhanced electrochemical response in capacitive energy storage devices. Voltammetry response analysis is employed to quantify the charge storage contributions from both electrostatic adsorption effect (electrical double-layer capacitance) and highly reversible redox process (pseudocapacitance). The existence of electronic capacitance enables a positive correlation between surface capacitance and the ratio of micropores. Besides, an electron-dependent correlation between the electroactive functional groups and redox reaction induced capacitance is also explored. This work will advance the capacitive energy storage field by presenting a clear understanding of the ion-sorption dynamics in the functionalized porous carbons.

DNA origami technology enables the precise assembly of well-defined two-dimensional and three-dimensional nanostructures with DNA, an inherently biocompatible material. Given their modularity and addressability, DNA origami objects can be used as scaffolds to fabricate larger higher-order structures with other functional biomolecules and engineer these molecules with nanometer precision. Over the past decade, these higher-order functional structures have shown potential as powerful tools to study the function of various bio-objects, revealing the corresponding biological processes, from the single-molecule level to the cell level. To inspire more creative and fantastic research, herein, we highlight seminal works in four emerging areas of bioapplications of higher-order DNA origami structures: (1) assisting in single-molecule studies, including protein structural analysis, biomolecule interaction analysis, and protein functional analysis, (2) manipulating lipid membranes, (3) directing cell behaviors, and (4) delivering drugs as smart nanocarriers. Finally, current challenges and opportunities in the fabrication and application of DNA origami-based functional structures are discussed.

Cu2BaSn(S,Se)4(CBTSSe) has recently gained substantial attention as an alternative absorber material for photovoltaic (PV) and photoelectrochemical (PEC) applications due to the abundance of the constituent elements, a large absorption coefficient, tunable band gap ranging from 1.5 to 2 eV, and reduced tendency for antisite disorder relative to Cu2ZnSn(S,Se)4. In this study, as an alternative to more expensive vacuum-based film-deposition processes, we report a low-toxicity solution-based process for the fabrication of high quality CBTSSe absorber layers with micrometer-scale film thickness and grain size. The facile process involves spin-coating an environmentally benign solution of highly soluble, inexpensive, and commercially available precursors, Ba(NO3)2, Cu(CO2CH3)2, and SnI2, followed by sequential sulfurization/selenization annealing. A high-temperature prebaking step under sulfur vapor is needed for each film layer to avoid forming the difficult-to-remove impurity phase, Ba(SO4), when starting from the soluble Ba(NO3)2reagent. The solution-based CBTSSe films have been employed in a Pt/TiO2/CdS/CBTSSe photocathode structure (e.g., for water splitting), exhibiting an ∼10 mA/cm2current density at 0 VRHE, comparable to that of vacuum-deposited CBTSSe PEC devices. Our approach for the fabrication of CBTSSe absorbers represents a first step in achieving low-cost and large-scale solution-processed solar devices based on this material.

A two-step approach was reported to fabricate cobaltous hydroxide/γ- nickel oxide hydroxide/reduced graphene oxide (Co(OH)2/γ-NiOOH/RGO) nanocomposites on nickel foam by combining the reduction of graphene oxide with the help of reflux condensation and the subsequent hydrothermal of Co(OH)2on RGO. The microstructural, surface morphology and electrochemical properties of the Co(OH)2/γ-NiOOH/RGO nanocomposite were investigated. The results showed that the surface of the first-step fabricated γ-NiOOH/RGO nanocomposites was uniformly coated by Co(OH)2nanoflakes with lateral size of tens of nm and thickness of several nm. Co(OH)2/γ-NiOOH/RGO nanocomposite demonstrated a high specific capacitance (745 mF/cm2at 0.5 mA/cm2) and a cycling stability of 69.8% after 1000 cycles at 30 mV/cm2. γ-NiOOH/RGO//Co(OH)2/γ-NiOOH/RGO asymmetric supercapacitor was assembled, and maximum gravimetric energy density of 57.3 W∙h/kg and power density of 66.1 kW/kg were achieved. The synergistic effect between the highly conductive graphene and the nanoflake Co(OH)2structure was responsible for the high electrochemical performance of the hybrid electrode. It is expected that this research could offer a simple method to prepare graphene-based electrode materials.

Using the giant magnetoelastic effect in the soft systems for ambient energy harvesting, namely, the magnetoelastic generator (MEG), is challenged by its relatively low voltage output. A conventional transformer could be employed to solve the problem by increasing the voltage at the expense of current; however, it holds a bulky and rigid configuration with considerable energy loss. Here, we developed the resistance-controllable magnetic induction (MI) layer with multi-walled carbon nanotubes (MWCNT) as an inner transformer to manipulate the electrical output of an MEG. With high electrical conductivity, flexibility, and mechanical strength, the resistance of the MWCNT-based MI layer can be designed by thickness, width, length, and turns of the coils, contributing to a power-transforming effect. As the resistances increased, the open-circuit voltage increased, while the short-circuit current showed a reversed trend. With a power density of 0.23 mV cm−2, the power-transforming MEG can charge a commercial capacitor at a rate of 0.63 mV s−1with intrinsic waterproofness. This work introduces a compelling approach to boost the voltage output of the MEG viainternally engineering the resistance of the MI layer.

The precipitation anomaly over Borneo features a dipolar pattern under the influence of the Madden‐Julian Oscillation (MJO). To understand the formation mechanisms of this pattern, a linear theory is developed to study the factors controlling its diurnal cycles and the dipolar pattern. The theory predicts that the prevailing wind is primarily responsible for the asymmetry over an idealized island, while the topography plays a critical role in the leeward convergence and convection asymmetry. The results are largely consistent with the observed composites of the dipole at Borneo. Nonlinear cloud‐permitting simulations are further conducted to test the effects of island topography and solar radiative heating in different MJO phases. The results show that the island topography can cause the mesoscale flow to split around the mountain due to the topographic blocking, and favor the development of the lee side sea breeze. These processes strengthen the low‐level convergence and convection at the leeside of the island during the late afternoon and night, which is very important to the formation of island dipolar precipitation anomaly. In contrast, the inland convergence is weakened and the dipole disappears when the terrain is flattened. The diurnal cycle of solar insolation is the dominant factor driving the land‐sea breeze circulation, which intensifies the island convection at the leeside. These results indicate that the MJO wind anomaly, island topography and solar insolation play distinct roles in the formation of the dipolar pattern of Borneo precipitation. Rainfall over the Borneo island varies significantly during the course of a day. It initiates during the late afternoon, reaches the peak during the late night, and propagates offshore afterward. Rainfall is often enhanced in western Borneo, and suppressed in its east region every 20–90 days. This spatial pattern also reverses sometimes. While these characteristics are important for predicting of rainfall over the tropical island, it remains unclear where the pattern comes from. Here, we study the factors that controls these characteristics. We consider three important factors: solar insolation that varies during time of the day, low‐level zonal wind that changes every 20–90 days, and the island topography. Results from a simple model and complex numerical simulations indicate that all these factors make distinct contributions to the rainfall pattern over the island. A linear theory suggests that the dipolar pattern of precipitation over Borneo is primarily caused by intraseasonal wind associated with the Madden‐Julian Oscillation (MJO)Cloud‐permitting numerical simulations indicate that the island topography can strengthen the dipole in the presence of the prevailing windSolar insolation, MJO intraseasonal zonal wind, and island topography are all important for the precipitation dipole over Borneo A linear theory suggests that the dipolar pattern of precipitation over Borneo is primarily caused by intraseasonal wind associated with the Madden‐Julian Oscillation (MJO) Cloud‐permitting numerical simulations indicate that the island topography can strengthen the dipole in the presence of the prevailing wind Solar insolation, MJO intraseasonal zonal wind, and island topography are all important for the precipitation dipole over Borneo

The current technological advances in respiratory sensors and their implementations for point‐of‐care monitoring of COVID‐19 are systematically summarized. We highlight the respiratory sensors for biomechanical signal monitoring, such as the respiratory rate and cough frequency, as well as biochemical signal monitoring, such as exhaled breath analysis. Wearable point‐of‐care system enabled by advanced respiratory sensors is expected to promote better control of the pandemic by diagnosis by providing accessible, continuous, widespread, noninvasive, and reliable monitoring of COVID‐19.

Since its outbreak in 2019, COVID‐19 becomes a pandemic, severely burdening the public healthcare systems and causing an economic burden. Thus, societies around the world are prioritizing a return to normal. However, fighting the recession could rekindle the pandemic owing to the lightning‐fast transmission rate of SARS‐CoV‐2. Furthermore, many of those who are infected remain asymptomatic for several days, leading to the increased possibility of unintended transmission of the virus. Thus, developing rigorous and universal testing technologies to continuously detect COVID‐19 for entire populations remains a critical challenge that needs to be overcome. Wearable respiratory sensors can monitor biomechanical signals such as the abnormities in respiratory rate and cough frequency caused by COVID‐19, as well as biochemical signals such as viral biomarkers from exhaled breaths. The point‐of‐care system enabled by advanced respiratory sensors is expected to promote better control of the pandemic by providing an accessible, continuous, widespread, noninvasive, and reliable solution for COVID‐19 diagnosis, monitoring, and management. Wearable respiratory sensors can monitor biomechanical signals such as the abnormities in respiratory rate and cough frequency caused by COVID‐19, as well as biochemical signals such as virus biomarkers from exhaled breaths. The point‐of‐care system enabled by advanced wearable respiratory sensors is expected to promote better control of the pandemic by providing an accessible, continuous, widespread, noninvasive, and reliable solution for COVID‐19 diagnosis, monitoring, and management.

Interpreting 21 cm measurements from current and upcoming experiments like HERA and the SKA will provide new scientific insights and exciting implications for astrophysics and cosmology regarding the Epoch of Reionization (EoR). Several recent works have proposed using machine learning methods, such as convolutions neural networks (CNNs), to analyze images of reionization generated by these experiments since they could take full advantage of the information contained in the image. Generally, these studies have used only a single semi-numeric method to generate the input 21 cm data. In this work, we investigate the extent to which training CNNs for reionization applications depends on the underlying semi-numeric models. Working in the context of predicting CMB τfrom 21 cm images, we compare networks trained on similar data sets from 21cmFASTand zreion, two widely used semi-numeric reionization methods. We show that neural networks trained on input data from only one model produce poor predictions on data from the other model. Satisfactory results are only achieved when both models are included in the training data. This finding has important implications for future analyzes on observation data, and encourages the use of multiple models to produce images that capture the full complexity of the EoR.

At the forefront of the smart textile community, healthcare and sustainability are the two crucial objectives targeted by researchers. The development of such powerful devices has been driven by innovative fabrications of breathable, skin-conformable technologies through the use of functional and programmable materials and device structures. This Perspective focuses on the current smart textiles available in the research field, categorized into personalized healthcare, including diagnostics and therapeutics, and sustainability, including energy harvesting and conservation─personalized thermoregulation. These categories are further broken down into their platform structural technologies and performances. Furthermore, we give a comprehensive overview and highlight a few examples of current studies. Finally, we provide an outlook on these technologies for future researchers to participate. We envision that the next generation of smart textiles will revolutionize wearable technology for healthcare and sustainability.

In digital image correlation, the iterative spatial domain cross-correlation algorithm is considered as a gold standard for matching the corresponding points in two images, but requires an accurate initial guess of the deformation parameters to converge correctly and rapidly. In this work, we present a fully automated method to accurately initialize all points of interest for the deformed images in the presence of large rotation and/or heterogeneous deformation. First, a robust computer vision technique is adopted to match feature points detected in reference and deformed images. The deformation parameters of the seed point are initialized from the affine transform, which is fitted to the matched feature points around it. Subsequently, the refined parameters are automatically transferred to adjacent points using a modified quality-guided initial guess propagation scheme. The proposed method not only ensures a rapid and correct convergence of the nonlinear optimization algorithm by providing a complete and accurate initial guess of deformation for each measurement point, but also effectively deals with deformed images with relatively large rotation and/or heterogeneous deformation. Tests on both simulated speckle images and real-world foam compression experiment verify the effectiveness and robustness of the proposed method.

MXenes are attracting growing attentions from scientific community owing to their decent electric and ionic conductivity, highly accessible surface area, and the presence of redox-active sites. Herein, an acid molecular scissor is proposed to artificially tailor Ti3CNTxMXene at the atomic scale and create defective nanosheets and redox-active sites. The tailored Ti3CNTxMXene exhibits a significantly improved electrochemical performance with the specific capacitance reaching 376 F g−1and 230.68 mF cm−2, much higher than that of original Ti3CNTxMXene (237 F g−1and 168.27 mF cm−2). The tailored Ti3CNTxMXene was further assembled into a micro-supercapacitor, which demonstrates a high volumetric capacitance of 250 F cm−3, a high energy density of 12.46 mW h cm−3at a power density of 0.43 W cm−3. This work offers a new strategy to reinvent MXenes at the atomic scale with largely enhanced redox-active sites for energy storage, catalysis, solid lubricants and electromagnetic interference shielding.

Pervasive and portable energy solutions are highly desired in the era of Internet of Things for powering wide-range distributed electronics. Human body contains renewable biomechanical energy sources, which could be harnessed for sustainable electricity generation as portable power sources for wearable bioelectronics. Herein, we propose an ultralow-cost, efficient, portable hand-driven triboelectric nanogenerator (HD-TENG) enabled by whirligig spinning to harvest energy from low-frequency and linear human biomechanical motions. Remarkably, the operating HD-TENG could easily achieve a rotational speed of over 10,000 rpm with a gentle hand stretching in a linear and periodic manner. The reported HD-TENG was demonstrated to charge a 220 μF commercial capacitor up to 3 V in less than 80 s, and continuously drive a smart bracelet for health monitoring, and a portable MPEG-1 audio layer III for music playing. With a collection features of high output power, light weight, excellent portability, ease of transport, cost-effectiveness, and environmental friendliness, the ingeniously designed HD-TENG represents a convenient green power supply approach for wearable bioelectronics in the era of Internet of Things.

In this study, we present the observation of the giant magnetoelastic effect that occurs in soft elastomer systems without the need of external magnetic fields and possesses a magnetomechanical coupling factor that is four times larger than that of traditional rigid metal-based ferromagnetic materials. To investigate the fundamental scientific principles at play, we built a linear model by using COMSOL Multiphysics, which was consistent with the experimental observations. Next, by combining the giant magnetoelastic effect with electromagnetic induction, we developed a magnetoelastic generator (MEG) for biomechanical energy conversion. The wearable MEG demonstrates an ultrahigh output current of 97.17 mA, a low internal impedance of around ∼40 Ω, and an intrinsic waterproof property. We further leveraged the wearable MEG as an ultrahigh current power source to drive a Joule-heating textile for personalized thermoregulation, which increased the temperature of the fiber-shaped resistor by 0.2 °C. The development of the wearable MEG will act as an alternative and compelling approach for on-body electricity generation and arouse a wide range of possibilities in the renewable energy community.

The efficient conversion of ultrasound into electrical energy remains a highly desirable wireless powering solution, with potentially profound ramifications in energy transfer across virtually all industrial fields, especially for implantable medical devices. Triboelectric nanogenerators have been shown to effectively carry out ultrasound energy transduction, though efficiency remains poor. Here, we devised a computational model to investigate the optimal triboelectric nanogenerator irradiation conditions, including frequencies, distances, sizes, and design, as represented by irradiated triboelectric surface area displacement. Our investigation may set the foundations for the establishment of a standardized protocol for efficient ultrasound mechanical energy harvesting. This holds considerable significance and could be paramount in designing an ever-growing number of applicative solutions in wireless energy transfer, providing a scalable, cost effective and time saving solution in the development of implantable medical devices.

Developing lightweight, flexible, and foldable electrodes with decent mechanical durability and electrochemical activity is a highly desirable goal for solid-state electrochemical energy storage devices yet remains a formidable challenge to overcome. Herein, we invent a freestanding robust PANI membrane via introducing the dynamic boronate bond to bridge rigid PANI chains with complaint polyvinyl alcohol (PVA) chains. The resultant PANI/PVA membrane (PPM) exhibits remarkable elasticity (17.8% strain) along with excellent tensile strength (33.7 MPa), outperforming the majority of existing state-of-the-art flexible electrochemical PANI membranes. Additionally, the PPM can be further assembled into a wearable solid-state supercapacitor with high electrochemical performance as well as decent mechanical durability. The lightweight, flexible, and foldable PANI membrane represents a great advancement in electrode materials for next-generation wearable solid-state electrochemical energy storage devices.

Harvesting biomechanical energy from low-frequency human body motions is a challenging but promising approach to powering the future wearables. Herein, we report a linear-to-rotary hybrid nanogenerator (LRH-NG) to effectively harvest low-frequency body biomechanical energy via a frequency enhancement strategy. Remarkably, the generated current and voltage by the LRH-NG from human body movement are respectively enhanced up to 3.1 times and 3.6 times of that at the basic frequency (2 Hz). Furthermore, the LRH-NG was demonstrated as an on-body electricity generator that can sustainably power a body area network with a temperature sensor and a humidity sensor for personalized health care. The designed LRH-NG may open up a new approach for high-performance low-frequency wearable biomechanical energy harvesting as a sustainable and pervasive energy solution in the era of the Internet of things.