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Textile‐based electromechanical sensors are increasingly used as wearable sensors for various applications, such as health monitoring and human‐machine interfaces. These sensors are becoming increasingly popular as they offer a comfortable and conformable sensing platform and possess properties that can be tuned by selecting different fiber materials, yarn‐spinning techniques, or fabric fabrication methods. Although it is still in its early stages, recent attempts have been made to introduce auxeticity to textile sensors to enhance their sensitivity. Having a negative Poisson's ratio, i.e., undergoing expansion laterally when subjected to tensile forces and contraction laterally under compressive forces, makes them distinct from conventional sensors with positive Poisson's ratio. This unique feature has demonstrated great potential in enhancing the performance of electromechanical sensors. This review presents an overview of electromechanical sensors based on auxetic textiles (textiles made from auxetic materials and/or non‐auxetic materials but with auxetic structures), specifically focusing on how the unique auxetic deformation impacts sensing performance. Sensors based on different working mechanisms, including piezoelectric, triboelectric, piezoresistive, and piezocapacitive, are covered. It is envisioned that incorporating auxeticity and electromechanical sensing capabilities into textiles will significantly advance wearable technology, leading to new sensors for health monitoring, fitness tracking, and smart clothing. [ABSTRACT FROM AUTHOR]

Electronic skin is increasingly receiving tremendous attention for its potential applications in medical rehabilitation and human‐machine interaction. However, the trade‐off between detection range and sensitivity of e‐skin has not been well addressed, although various strategies have been proposed. Interlocked microridges between the epidermis and dermis can effectively transfer stress to mechanoreceptors, allowing human skin to exhibit excellent sensitivity even upon both subtle and large external stimuli. Herein, inspired by human skin, a novel bionic e‐skin is developed in which interlocked microridges are introduced between the sensitive layer and interdigitated electrode. Thanks to the interlocked microridges, excellent compression capability and remarkable change of contact area between sensitive layer and interdigitated electrode can be achieved and the e‐skin exhibits an ultrahigh sensitivity (≈1502.5 kPa−1), excellent durability (10 000 cycles), a short response time (10 ms) as well as a wide detection range (≈160 kPa). Moreover, due to the effective transmission of external stress from a sensitive layer to an interdigitated electrode, such bionic e‐skin has ability to detect a wide range of human vital signs and vibrations caused by sound waves. Such facile preparation of bionic interlocked microridges opens a new pathway to achieve high‐performance e‐skins and extend their application prospects in future wearable intelligent systems. [ABSTRACT FROM AUTHOR]

With the rise of demand for smart wearable and flexible electronic devices in the modern world, high‐performance hybrid mechanical energy harvesters (HMEHs), which can easily convert biomechanical energy into electricity for powering a variety of portable electronic gadgets and operating smart sensors, have gained extensive interest. Herein, propose piezo/ferroelectric and dielectric niobium (Nb)‐doped bismuth titanate (Bi4Ti3‐xNbxO12, NBTO) plates, are proposed and synthesized by a molten‐salt synthesis technique, and they are further embedded into the poly(vinylidene fluoride‐co‐hexafluoropropylene) (NBTO/PVDF‐HFP) flexible composite film (CF) to construct a flexible HMEH. The prepared NBTO/PVDF‐HFP CFs reveal good piezo/ferroelectricity, β‐phase fraction, and dielectric properties, which can improve the electrical output performance of the HMEH. The 2 wt.% NBTO/PVDF‐HFP CF‐based HMEH exhibits high and stable electrical performance of ≈175 V, ≈5.8 µA, ≈76 µC m−2, and ≈2.02 W m−2, respectively. Furthermore, the durability and mechanical robustness analysis of the HMEH is conducted for several days. The real‐time applications of the HMEH are demonstrated by harvesting the biomechanical energy obtained from daily human activities and powering various portable electronics. Also, the HMEH integrated with an Arduino microcontroller unit is employed as a smart sensor switch for implementing smart home/building stair‐sensing applications and sending emergency e‐mail alerts. [ABSTRACT FROM AUTHOR]

This study introduces a novel wearable device that combines dual‐functional modules for energy storage and sensing. The device features an ionic gel serving as both the battery electrolyte and sensor dielectric layer, along with VO2‐nanoneedles electrodes. The solid‐state zinc‐ion battery module demonstrates a specific capacity of 286 mAh g−1, delivering consistent and long‐lasting power output even under variable pressure conditions. Moreover, the iontronic pressure sensor module exhibits high sensitivity, achieving 2.3 × 104 kPa−1, enabling precise detection of fingertip pulses and identification of respiratory patterns. The device's flexibility and structural resilience allow it to endure complex deformations, ensuring continuous operation in challenging environments. These results highlight the potential of the all‐in‐one device for wearable smart healthcare monitoring and management. [ABSTRACT FROM AUTHOR]

Human vision system remains alert for dangers and adopts high‐speed and low‐power coding methods to convert the image information to spike signals. To meet the demand for danger alert in machine vision, it is important to design intelligent sensors to integrate the functions of image perception and high‐efficiency coding for high‐priority analysis. Inspired by the human visual system, a MoS2 phototransistor is introduced on SiNx substrate enabling simultaneous image perception and time‐to‐first‐spike (TTFS) coding. The device demonstrates exceptional performance in encoding 3‐bit grayscale images, achieving a low mean squared error of 0.008 and a high structural similarity index of 0.9784. Spiking neural networks (SNN) with TTFS coding achieve high recognition accuracy (98.86%) while reducing spike count by 75%. The device array also perceives motion direction and object states by converting data temporally. This work establishes a hardware foundation to promote the performance of SNNs in efficiently identifying crucial information. [ABSTRACT FROM AUTHOR]

Achieving convenient, sensitive, low‐cost, and non‐contact detection of trace addictive drugs is a challenging problem. Herein, a novel ionically conductive metal‐organic framework (IC‐MOFs) is designed through a controlled interface assembly strategy. The active metal anions are incorporated into the layered MOFs with a porous structure, forming charge carriers that served as effective adsorption/binding sites for N‐methylphenethylamine (MPEA), a crucial simulator of addictive drugs. The in situ integrated Zn3(HHTP)2‐MOF sensor device designed in this study demonstrated real‐time detection of sub‐ppb level MPEA at room temperature, with an exceptionally low theoretical detection limit of 20 ppt. The overall sensing performance of this sensor surpassed all previously reported chemical sensors for detecting methamphetamine. The Zn3(HHTP)2‐MOF sensor exhibited outstanding selectivity, rapid response time (ca. 5 s), excellent long‐term stability, amenable miniaturization, and device consistency. The device successfully passed dual 85 test (500 h at 85 °C and 85% of humidity), which is rarely report previously. Density functional theoretical calculations (DFT) and spectral characterization confirmed that the prominent selectivity of Zn3(HHTP)2‐MOF toward MPEA is attributed to the strong binding ability. The general and straightforward strategy provides brand‐new route to exploiting smart sensors for drug prevention and surveillance. [ABSTRACT FROM AUTHOR]

Intelligent wearable sensors play a crucial role in the detection of toxic gases and monitoring physiological signals, thereby effectively ensuring environmental and personal health safety. Nonetheless, achieving the requirements for antibacterial properties, comfortable wear, and multifunctional detection remains a major challenge. In this study, a novel Def‐ZIF‐8/PPY/BC‐based flexible sensor is developed by in situ growth of zeolitic imidazolate frameworks‐8 (ZIF‐8) and polypyrrole (PPY) on bacterial cellulose (BC), followed by water immersion. The Def‐ZIF‐8/PPY/BC‐based flexible sensor demonstrates effective dual‐sensitivity responses to nitrogen dioxide (NO2) toxic gas and stress‐strain behaviors at room temperature. The structural characterization and theoretical calculations affirm that the innovative water treatment method successfully introduces defects into ZIF‐8, resulting in a significant 2.57‐fold improvement in response intensity to 80 ppm NO2. Stress‐strain sensing performance analysis reveals that the Def‐ZIF‐8/PPY/BC‐based flexible sensor exhibited high sensitivity (6.44 kPa−1), rapid response and recovery times (0.7/0.4 s), and exceptional cyclic stability (8000 cycles). Further, the inhibitory effect of ZIF‐8 on common bacterial strains contributes to the exceptional antibacterial properties (antibacterial rate exceeding 99%) of the Def‐ZIF‐8/PPY/BC based on the flexible sensor. This study offers a significant advancement in metal‐organic framework defect engineering and provides an effective strategy for developing multifunctional wearable sensors. [ABSTRACT FROM AUTHOR]

Every year, over 12 million people are enduring the persistent pain resulting from wound infections. In these chronic wounds, concealed infections may be covered up by scabs or granulation, which impeding accurate diagnosis and treatment. To address such clinical challenges, inspired by corals, a biomimetic microneedle patch (HepMi‐PCL) is developed to indicate and treat infections within wound. Relying on high‐precision 3D printing technology, each polycaprolactone microneedle own an equally sized porous shell and cavity with heparin‐based functional hydrogel filling in. After penetrating through the scab, HepMi‐PCL can absorb exudate in wound through surficial guide grooves and pores microstructure on its microneedle, thereby indicating whether anti‐infection is needed. Upon the identification of a positive chronic infection, HepMi‐PCL will smartly activate to release drugs rapidly. Subsequently, when the infection is effectively managed and the exudate progressively decreases, the drug delivery will correspondingly slow down or cease altogether. By leveraging autonomous response and therapeutic capabilities, HepMi‐PCL demonstrates the potential to expedite the diagnosis and treatment of infections, resulting in an enhancement of healing speed for infected wounds by over 200%. Thus, the integration of diagnostic and therapeutic functions of the microneedle patch is anticipated to offer novel approaches in addressing the management of chronic wounds. [ABSTRACT FROM AUTHOR]

Cultural heritage faces recurring degradation processes and natural aging phenomena, demanding the envisioning of innovative preservation solutions inspired by cutting‐edge scientific research. Over extended time frames, current preservation strategies often prove inadequate in preserving the different constituent materials of cultural assets, which are thus threatened by their inherent fragility and by the complex interactions with the surrounding environment. The distinctive properties of graphene and graphene‐related materials (GRMs) now offer unexplored opportunities in the field of cultural heritage, addressing various forms of deterioration phenomena. This work critically analyzes early‐stage literature on the use of graphene and GRMs. Strengths, weaknesses, and limitations in anti‐corrosion, anti‐fading, and consolidation properties of graphene and GRMs are thoroughly investigated, along with their possible applications in smart sensors to monitor the state of health of endangered artifacts. The aim is to elucidate how specific characteristics of graphene and GRMs can be applied to the conservation, diagnostics, and monitoring of artistic and archaeological assets. Future perspectives in the design of stable, long‐lasting, and compatible graphene‐based solutions for cultural heritage protection are highlighted, providing a detailed discussion on potentials and pitfalls. [ABSTRACT FROM AUTHOR]

With the ongoing advancement in sensor technologies, the development of intelligent, secure, and low‐carbon vehicles will be possible in the near future. However, providing continuous power to numerous onboard sensors consumes substantial amounts of power from vehicle, resulting in the shortened running times. Herein, a self‐powered noncontact triboelectric nanogenerator (SNC‐TENG) with ultralong‐distance detection and a high sensitivity is proposed, which can be used as ambient perception sensors for smart vehicles. The SNC‐TENG is constructed from a MXene/silicone nanocomposite with a fully embedded conductive sponge, which significantly enriches the tribo‐charges and leads to an excellent capability and performance. This SNC‐TENG is capable of perceiving human activity from a distance of 2 m. To the best of authors knowledge, the perceiving distance per unit area of this SNC‐TENG is the highest among previously reported non‐contact TENGs. Furthermore, the applicability of the SNC‐TENG is explored for vehicle sentry mode and blind spot detection for the first time. The use of this technology in a real vehicle demonstrates its feasibility for use in practical applications. Overall, this study provides a new design scheme for contactless self‐powered sensors, and the presented SNC‐TENG is expected to be applicable in various fields where non‐contact sensing is required. [ABSTRACT FROM AUTHOR]

Triboelectric probes have rapidly developed as an efficient tool for understanding contact electrification at liquid–solid interfaces. However, the liquid–solid electrification process is susceptible to interference from chemical components in mixed solutions, severely limiting the potential applications of triboelectric probes in various liquid environments. This study for the first time reports a triboelectric probe capable of sucrose solution concentration sensing, finding that the dissolution of sucrose destroys the hydrogen bond network between water molecules and forms sucrose–water hydrogen bonds, which alters the fluid mechanics characteristics of the solution and enhances its conductivity, thereby reducing the droplet size and causing an ion charge shielding effect that significantly affects the electron transfer in liquid–solid contact electrification. Owing to the feedback of the triboelectric probe on the sucrose concentration gradient‐type sensing electrical signals, efficient sensing of sucrose solution was achieved (sensitivity of −0.0038%−1, response time of 90 ms). The triboelectric probe is also used as a wireless smart terminal to enable real‐time detection of sucrose solution. This work contributes to the understanding of the structure–function relationship between micro hydrogen bonding and macro performance, and provides a promising solution for building sustainable intelligent sensors. [ABSTRACT FROM AUTHOR]

Hydrogel actuators, capable of generating reversible deformation in response to external stimulus, are widely considered as new emerging intelligent materials for applications in soft robots, smart sensors, artificial muscles, and so on. Peptide self‐assembly is widely applied in the construction of intelligent hydrogel materials due to their excellent stimulus response. However, hydrogel actuators based on peptide self‐assembly are rarely reported and explored. In this study, a pH‐responsive peptide (MA‐FIID) is designed and introduced into a poly(N‐isopropyl acrylamide) backbone (PNIPAM) to construct bilayer and heterogeneous hydrogel actuators based on the assembly and disassembly of peptide molecules under different pH conditions. These peptide‐containing hydrogel actuators can perform controllable bending, bucking, and complex deformation under pH stimulation. Meanwhile, the Hofmeister effect of PNIPAM hydrogels endows these peptide‐containing hydrogels with enhanced mechanical strength, ionic stimulus response (CaCl2), and excellent shape‐memory property. This work broadens the application of supramolecular self‐assembly in the construction of intelligent hydrogels, and also provides new inspirations for peptide self‐assembly to construct smart materials. [ABSTRACT FROM AUTHOR]

Smart textile for sensor is identified as a superior platform with greatly improved convenience and comfort for wearable bioelectronics. However, most reported textile‐based sensors cannot fully demonstrate the inherent advantages of textiles, such as comfortability, breathability, biocompatibility, and environmental friendliness, mainly due to the intrinsic limitation of non‐textile or inorganic components. Here, an all‐textile, all‐organic, washable, and breathable sensor with discriminable pressure, proximity, and temperature sensing function is first reported. Multiple sensing functions and outstanding washability are demonstrated. The all‐textile sensor can also be seamlessly integrated into diverse types of fabrics to realize wide‐range sensing of human activities and noncontact stimuli without sacrificing biocompatibility and comfortability. Additionally, by combining with the deep‐learning technique, an all‐textile sensing system is established to recognize object shape, contactless trajectory, and even environmental temperature. These results open a new avenue for designing low‐cost, washable, comfortable, and biocompatible green textile electronics, providing a meaningful guideline in intelligent textiles. [ABSTRACT FROM AUTHOR]

Conductive hydrogel‐based epidermal sensors are regarded with broad prospects in bridging the gap between human and machine for personalized healthcare. However, it is still challenging to simultaneously achieve high sensitivity, wide sensing range, and reliable cycling stability in hydrogel‐based epidermal sensors for ultrasensitive human–machine interfacing, along with brilliant antiswelling capability, and near‐infrared (NIR) light‐triggered dissociation and drug release for further smart on‐demand photothermal therapy. Herein, the facile preparation of a flexible multifunctional epidermal sensor from the elaborately fabricated, highly stretchable, and antiswelling MXene hydrogel is presented. It exhibits high sensitivity, wide sensing range (up to 350% strain), and reliable reproducibility for enabling ultrasensitive human‐machine interfacing. It displays excellent antiswelling capability for the hydrogel to avoid expanding the wound due to excessive swelling for further reliable wound therapy. Furthermore, it possesses good biocompatibility and robust photothermal performance for the smart photothermal therapy after healthcare monitoring. Meanwhile, the sensor can be triggered to be softened and partly dissociated under the prolonged NIR light irradiation with the transformation of the temperature‐sensitive low‐melting‐point Agar into a sol state and the partial dissociation in the hydrogel to release the loaded drug on demand for synergistically sterilizing bacteria and efficiently promoting wound healing. [ABSTRACT FROM AUTHOR]

Flexible conductive materials with intrinsic structural characteristics are currently in the spotlight of both fundamental science and advanced technological applications due to their functional preponderances such as the remarkable conductivity, excellent mechanical properties, and tunable physical and chemical properties, and so on. Typically, conductive hydrogel fibers (CHFs) are promising candidates owing to their unique characteristics including light weight, high length‐to‐diameter ratio, high deformability, and so on. Herein, a comprehensive overview of the cutting‐edge advances the CHFs involving the architectural features, function characteristics, fabrication strategies, applications, and perspectives in flexible electronics are provided. The fundamental design principles and fabrication strategies are systematically introduced including the discontinuous fabrication (the capillary polymerization and the draw spinning) and the continuous fabrication (the wet spinning, the microfluidic spinning, 3D printing, and the electrospinning). In addition, their potential applications are crucially emphasized such as flexible energy harvesting devices, flexible energy storage devices, flexible smart sensors, and flexible biomedical electronics. This review concludes with a perspective on the challenges and opportunities of such attractive CHFs, allowing for better understanding of the fundamentals and the development of advanced conductive hydrogel materials. [ABSTRACT FROM AUTHOR]

Strain and temperature are important physiological parameters for health monitoring, providing access to the respiration state, movement of joints, and inflammation processes. The challenge for smart wearables is to unambiguously discriminate strain and temperature using a single sensor element assuring a high degree of sensor integration. Here, a dual‐mode sensor with two electrodes and tubular mechanically heterogeneous structure enabling simultaneous sensing of strain and temperature without cross‐talk is reported. The sensor structure consists of a thermocouple coiled around an elastic strain‐to‐magnetic induction conversion unit, revealing a giant magnetoelastic effect, and accommodating a magnetic amorphous wire. The thermocouple provides access to temperature and its coil structure allows to measure impedance changes caused by the applied strain. The dual‐mode sensor also exhibits interference‐free temperature sensing performance with high coefficient of 54.49 µV °C−1, low strain and temperature detection limits of 0.05% and 0.1 °C, respectively. The use of these sensors in smart textiles to monitor continuously breathing, body movement, body temperature, and ambient temperature is demonstrated. The developed multifunctional wearable sensor is needed for applications in early disease prevention, health monitoring, and interactive electronics as well as for smart prosthetics and intelligent soft robotics. [ABSTRACT FROM AUTHOR]

Examples of anisotropic movement paired with helical geometry abound in the animal and plant kingdoms are used for a variety of reasons, such as diverse social signaling directed at conspecifics or camouflage to avoid predation. Inspired by these natural phenomena, a smart sensor is developed with a chiroptical 3D actuator that can fold, bend, and twist in response to external stimuli, reflecting light of specific wavelengths, and possessing circular polarization properties. Chirophotonic crystal actuators are constructed with an asymmetric Janus structure and are fabricated by self‐assembly, screen printing, and in situ photopolymerization. The optically active layer consists of cholesteric liquid crystal polymer, and the mechanically active layer is composed of a polymeric gel thin film. The programmed in‐planar and out‐of‐planar asymmetric Janus structures control the directionality of various shapes morphing from 2D to 3D. Finite element simulations allow to predict the shape changes associated with these chirophotonic crystal actuators: flower blooming, tendril climbing, eagle hunting, ant lifting, and inchworm moving motions. By utilizing the chirophotonic crystal actuator, a reusable and portable methanol‐laced water identifier is developed. [ABSTRACT FROM AUTHOR]

3D conformable electronic devices on freeform surfaces show superior performance to the conventional, planar ones. They represent a trend of future electronics and have witnessed exponential growth in various applications. However, their potential is largely limited by a lack of sophisticated fabrication techniques. To tackle this challenge, a new direct freeform laser (DFL) fabrication method enabled by a 5‐axis laser processing platform for directly fabricating 3D conformable electronics on targeted arbitrary surfaces is reported. Accordingly, representative laser‐induced graphene (LIG), metals, and metal oxides are successfully fabricated as high‐performance sensing and electrode materials from different material precursors on various types of substrates for applications in temperature/light/gas sensing, energy storage, and printed circuit board for circuit. Last but not the least, to demonstrate an application in smart homes, LIG‐based conformable strain sensors are fabricated and distributed in designated locations of an artificial tree. The distributed sensors have the capability of monitoring the wind speed and direction with the assistance of well‐trained machine‐learning models. This novel process will pave a new and general route to fabricating 3D conformable electronic devices, thus creating new opportunities in robotics, biomedical sensing, structural health, environmental monitoring, and Internet of Things applications. [ABSTRACT FROM AUTHOR]

With the vigorous development of the Internet of Things and artificial intelligence, the active sensing system based on triboelectric nanogenerators plays an excellent performance potential and application value as a pioneering technology for smart manufacturing. Nevertheless, achieving material innovation to strike a good balance between active sensing systems and environmental friendliness remains a difficult task. As the most abundant biopolymer on earth, the sustainability potential and excellent performance of cellulose are of great importance for the development of smart sensing systems. This review intends to provide a new perspective on the sustainability of smart active sensing systems to design and fabricate cellulosic triboelectric materials for self‐powered sensing systems. Herein, the structure and advantageous properties of cellulosic triboelectric materials are briefly described. Furthermore, the structure–property–application relationship of the materials is addressed from the perspective of material design and structure optimization. Next, the latest applications of cellulose triboelectric materials are comprehensively described in smart sensing fields such as environmental monitoring, smart home, smart medical, human–machine interaction, and the Internet of everything. Lastly, the current challenges and future developments of cellulose triboelectric materials for smart sensor systems are presented. [ABSTRACT FROM AUTHOR]

Flexible epidermic sensors made from conductive hydrogels are holding bright potential in personalized healthcare, multifunctional electronic skins, and human‐machine interfaces. However, it is still a great challenge to simultaneously realize conductive hydrogel‐based epidermic sensors with reliable self‐healing ability and remarkable sensing performances in high‐performance healthcare (especially electrophysiological signals) sensing for wearable human‐machine interaction, as well as accelerated wound healing for subsequent medical treatment together. Herein, a flexible healable high‐performance epidermic sensor is assembled from the facilely prepared antibacterial MXene hydrogel with efficiently accelerated wound healing for sensitively wearable human‐machine interaction. The as‐prepared hydrogel possesses enhanced mechanical performance, outstanding healable capability, reliable injectability, facile degradability, excellent biocompatibility, and robust antibacterial ability, which is capable of being assembled into a multifunctional epidermic sensor to sensitively monitor human movements for rehabilitation training, to detect tiny electrophysiological signals for the diagnosis of cardiovascular‐ and muscle‐related diseases, and to be employed for wearable human‐machine interaction. In addition, the hydrogel can be utilized to treat wound infection and can effectively accelerate wound healing. Thus, it sheds light on preparing flexible healable epidermic sensors with multifunctional integration of personal health diagnosis and smart medical treatment for wearable human‐machine interaction and next‐generation artificial skins. [ABSTRACT FROM AUTHOR]

Air contamination is one of the foremost concerns of environmentalists worldwide, which has elevated global public health concerns for monitoring air contaminants and implementing appropriate safety policies. These facts have generated nascent global demand for exploring sustainable and translational strategies required to engineer affordable, intelligent, and miniaturized sensors because commercially available sensors lack lower detection limits, room temperature operation, and poor selectivity. The state‐of‐the‐art sensors are concerned with architecting advanced nanomaterials to achieve desired sensing performance. Recent studies demonstrate that neither pristine metal carbides/nitrides (MXenes) nor polymers (P) can address these practical challenges. However, synergistic combinations of various precursors as hybrid‐nanocomposites (MXP‐HNCs) have emerged as superior sensing materials to develop next‐generation intelligent environmental, industrial, and biomedical sensors. The expected outcomes could be manipulative due to optimizing physicochemical and morphological attributes like tunable interlayer‐distance, optimum porosity, enlarged effective surface area, rich surface functionalities, mechanical flexibility, and tunable conductivity. This review intends to detail a comprehensive summary of the advancements in state‐of‐the‐art MXP‐HNCs chemiresistors. Moreover, the underlying sensing phenomenon, chemiresistor architecture, and their monitoring performance are highlighted. Besides, an overview of challenges, potential solutions, and prospects of MXP‐HNCs as next‐generation intelligent field‐deployable sensors with the integration of IoT and AI are outlined. [ABSTRACT FROM AUTHOR]

Conductive hydrogels have recently gained impressive attention in biological medicine and intelligent electronics. Despite the multifunctions demonstrated by existing conductive hydrogels, it is still a challenge to introduce a hydrogel to adjust the distance between the peritumoral organs and the tumor, reducing the radiation damage to the peritumoral organs. Here, a hydrophobic associating hydrogel with multiple desirable features is fabricated based on diverse supramolecular assembly. The introduction of MXene and hydrolyzed keratin (HK) imparts the hydrogel with excellent conductivity, ultra‐stretchability (>2000%), and good self‐adhesion. Moreover, the hydrogel is utilized as an intelligent sensor intended for monitoring various human movements and physiological signals, demonstrating a wide strain window, the rapid response time (130 ms), and outstanding strain sensitivity (GF = 10.22). Inspired by balloon inflation, the hydrogel is designed to separate the tumor from the peritumoral organs in brachytherapy. It plays a role in reducing the radiation dose and damage to the peritumoral organs. The authors also simulate the attenuation process of the radiation signal according to the change of the hydrogel size and develop a smartphone application (app) to monitor the safety range of the different radiation risks, manifesting its great potential in soft intelligent sensors. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) are attractive in powering sensors for smart power grids. Herein, a TENG based on a rotational magnetic ball is presented to harvest the magnetic energy of transmission lines. The magnetic ball rolls in a spherical shell under the alternating magnetic field generated by the transmission line. The centrifugal force produced during the rotation is used to drive a TENG unit (ten times the weight of the magnetic ball and shell) to generate electricity with the assistance of coil springs. The device can maintain the stability of the output performance under high current shocks; meanwhile, the open‐circuit voltage, output power, and operating frequency of a single TENG unit can reach 1.5 kV, 6.67 mW, and 20 Hz, respectively. Furthermore, a wireless alarm system for monitoring the temperature and dip angle of transmission lines is successfully driven by this device. This work demonstrates an efficient and nontraditional strategy for harvesting magnetic energy through TENG, which is applied to power‐distributed and self‐powered sensors for monitoring transmission lines. [ABSTRACT FROM AUTHOR]

Main‐chain cholesteric liquid crystal polymers are a promising candidate for the development of responsive photonic devices due to the combination of selective reflection and soft, elastic properties, but it is difficult to enhance these materials with new kinds of responsiveness due to the inherent lack of mesogenic side groups. Here, a new strategy is showed to obtain a dual‐responsive elastic cholesteric polymer material by preparing a semi‐interpenetrating network consisting of a cholesteric main‐chain polymer and a hygroscopic poly(ampholyte). The material is shown to undergo a redshift of the reflected color upon swelling with water, while the color blueshifts when a strain is applied. Color patterns can be prepared by localized photopolymerization at different temperatures, leading to brightly colored responsive images with high contrast. Due to the elastic nature of the material, it can easily be made into a wearable device, and its application as a multifunctional smart sensor for sweat detection and movement detection is demonstrated. The results show that new responsiveness can be added to main‐chain cholesteric polymers by preparation of interpenetrating networks, which can be further extended to develop various kinds of multi‐responsive smart materials. [ABSTRACT FROM AUTHOR]

Phase change materials provide unique reconfigurable properties for photonic applications that mainly arise from their exotic characteristic to reversibly switch between the amorphous and crystalline nonvolatile phases. Optical pulse based reversible switching of nonvolatile phases is exploited in various nanophotonic devices. However, large area reversible switching is extremely challenging and has hindered its translation into a technologically significant terahertz spectral domain. Here, this limitation is circumvented by exploiting the semiconducting nature of germanium antimony telluride (GST) to achieve dynamic terahertz control at picosecond timescales. It is also shown that the ultrafast response can be actively altered by changing the crystallographic phase of GST. The ease of fabrication of phase change materials allows for the realization of a variable ultrafast terahertz modulator on a flexible platform. The rich properties of phase change materials combined with the diverse functionalities of metamaterials and all‐optical ultrafast control enables an ideal platform for design of efficient terahertz communication devices, terahertz neuromorphic photonics, and smart sensor systems. [ABSTRACT FROM AUTHOR]

Metallic two‐dimensional conductive nanomaterials are extensively explored in stretchable strain sensors, which have promising applications ranging from health monitoring to human–machine manipulation. However, there are limited materials available in this category, and their sensing abilities need to be strengthened. Herein, a controllable deoxidation–nitridation strategy via the pyrolysis of an amine nitrogen source to synthesize oxygen‐doped vanadium nitride (VNO) nanosheets with high conductivity is reported. Its metallic characteristics and low dimensionality, together with layer‐to‐layer slippage make VNO particularly suitable for stretchable strain sensors with remarkable performance, including extraordinary sensitivity (a maximum gauge factor of 2667), wide detection range (0–100%), high durability (over 6000 cycles), and rapid response (44 ms). Furthermore, the strain sensors can capture various physiological signals; in particular, a state‐of‐the‐art wireless vehicle control system designed for differently abled people is fabricated based on the sensors. Moreover, by engineering the thickness of the VNO layer, it can behave as an elastic conductor, demonstrating its feasibility for stretchable wiring. [ABSTRACT FROM AUTHOR]

A photosensor with an amplitude‐tunable and polarity‐reversible response under gate modulation has potential as a computational photosensor, which can provide more recognition degree of data to enhance signal processing efficiency. Although, the ambipolar 2D semiconductors possess unique gate‐tunable properties, the question of how to utilize this property to design polarity‐reversible photodiodes for intelligent applications remains unanswered. Here, gate‐controllable polarity‐reversible photodiodes based on ambipolar 2D semiconductors with an asymmetrically metal‐contacted architecture are proposed. By controlling the gate‐field, the local carrier type and density profile can be manipulated in the channel due to the partial shielding feature of the asymmetrically metal‐contacted architecture, resulting in a polarity‐reversible photodiode. The reported WSe2‐based photodiode possesses excellent rectifying behavior with a rectification ratio over 105, photovoltaic performance with 90% external quantum efficiency, and 2.3% power conversion efficiency under gate regulation. Meanwhile, the device exhibits reversible polarity of photovoltage from a negative to positive state under gate control. By utilizing the reversible photovoltage of the WSe2 photodiode, an optoelectronic switch with a photovoltage polarity signal is demonstrated without a bias voltage. This photovoltage‐reversible homodiode paves the way to develop 2D devices with multiple operation modes for potential applications in high‐efficiency photovoltaics, intelligent vision sensors, and logic optoelectronics. [ABSTRACT FROM AUTHOR]

Detection and capture of toxic nitrogen oxides (NOx) is important for emissions control of exhaust gases and general public health. The ability to directly electrically detect trace (0.5–5 ppm) NO2 by a metal–organic framework (MOF)‐74‐based sensor at relatively low temperatures (50 °C) is demonstrated via changes in electrical properties of M‐MOF‐74, M = Co, Mg, Ni. The magnitude of the change is ordered Ni > Co > Mg and explained by each variant's NO2 adsorption capacity and specific chemical interaction. Ni‐MOF‐74 provides the highest sensitivity to NO2; a 725× decrease in resistance at 5 ppm NO2 and detection limit <0.5 ppm, levels relevant for industry and public health. Furthermore, the Ni‐MOF‐74‐based sensor is selective to NO2 over N2, SO2, and air. Linking this fundamental research with future technologies, the high impedance of MOF‐74 enables applications requiring a near‐zero power sensor or dosimeter, with the active material drawing <15 pW for a macroscale device 35 mm2 with 0.8 mg MOF‐74. This represents a 104–106× decrease in power consumption compared to other MOF sensors and demonstrates the potential for MOFs as active components for long‐lived, near‐zero power chemical sensors in smart industrial systems and the internet of things. [ABSTRACT FROM AUTHOR]

Motion vector sensors play an important role in artificial intelligence and internet of things. Here, a triboelectric vector sensor (TVS) based on a direct‐current triboelectric nanogenerator is reported, for self‐powered measuring various motion parameters, including displacement, velocity, acceleration, angular, and angular velocity. Based on the working mechanism of the contact‐electrification effect and electrostatic breakdown, a continuous DC signal can be collected to directly monitor moving objects free from environmental electromagnetic signal interference existing in conventional self‐powered TVSs with an alternative‐current signal output, which not only enhances the sensitivity of sensors, but also provides a simple solution to miniaturize the sensors. Its sensitivity is demonstrated to be equivalent to state‐of‐the‐art photoelectric technology by a comparative experiment in an intelligent mouse. Notably, an intelligent pen based on the miniaturized TVS is designed to realize motion trajectory tracing, mapping, and writing on the curved surface. This work provides a new paradigm shift to design motion vector sensors and self‐powered sensors in artificial intelligent and internet of things. [ABSTRACT FROM AUTHOR]

The fabrication and implementation of artificially intelligent sensor arrays has faced serious technical and/or cost-effectiveness challenges. Here, a new printing method is presented to produce a fully functional array of sensors based on monolayer-capped gold nanoparticles. The proposed printing technique is based on the so-called self-propelled antipinning ink droplet, from which evaporative deposition takes place along the path of motion. By applying actuating forces, different deposition line patterns with different thicknesses and morphology from a single droplet are generated. The functionality of the produced sensors is demonstrated by their ability to detect different representative volatile organic compounds (VOCs) belonging to different chemical families, including alcohols, alkanes, ethers, and aromatics, and under extremely different humidity levels resembling those encountered in real-world conditions. The results show that the sensors exhibit ultrasensitive sensing features, with an ability to detect and differentiate between different VOCs at low ppb levels. Additionally, the results show that the sensors are able to accurately predict VOC concentrations, viz. enable quantification capabilities, while nevertheless being inexpensive, do not need complicated and expensive printing equipment and prepatterning processes, allow low voltage operation, and provide a platform for multifunctional applications. [ABSTRACT FROM AUTHOR]

Encouraged by the increasing requirements of intelligent equipment, silicon integrated circuit–compatible photodetectors that support single‐chip photonic–electronic systems have gained considerable progresses. Advanced materials have resulted in enhanced device performance based on traditional photovoltaic effect and photoconductive effect, and novel device designs have catalyzed new working mechanisms combing rapid photoresponse and high responsivity gain. Surprising applications are developed using monolithic photonic–electronic platforms, and the developing integration strategies keep pace with the developing complementary metal‐oxide‐semiconductor techniques as well as nonsilicon substrates. Here, the recent developments in silicon‐compatible photodetectors, both in device advances and their integration routes, are reviewed. Meanwhile, the progresses, challenges, and possible future directions in this field are discussed and concluded. [ABSTRACT FROM AUTHOR]