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A triboelectric nanogenerator (TENG) can effectively convert high entropy mechanical energy from the environment into electrical energy and has broad application potential in self-powered microelectronics and intelligent sensing fields. However, the low output performance of a TENG is one of the bottlenecks that restrict its commercial application. Herein, we design a high-performance and ultrastable wind-driven TENG using a zirconium carbide-zirconia core–shell nanoparticles/polyvinyl chloride (ZrC@ZrO2/PVC) composite membrane and polyamide (PA) membrane as matched triboelectric materials. The investigations indicate that doping 0.9 wt % ZrC@ZrO2 core–shell nanoparticles in the PVC matrix and using 1000-grit sandpaper as a template can effectively boost the surface charge density of the triboelectric layer, so that the output performance of TENG can be improved. The optimized TENG produces a peak output voltage of 367 V, a peak output current of 40 μA, and a maximum output power of 3.2 mW under a wind speed of 17.9 m/s, which can charge a 10,000 uF commercial capacitor from 0 to 3 V within 240 s. The stored energy can supply power for 27 light-emitting diodes (LEDs) connected in parallel. Moreover, the TENG maintains a stable output performance after continuous working for 16 h and a week. This study provides a simple approach to enhance the surface charge density of the friction layer by adding core–shell structured nanoparticles and constructing a rough surface structure. [ABSTRACT FROM AUTHOR]

In recent years, triboelectric nanogenerators (TENGs) have garnered significant attention from researchers due to their exceptional performance and cost-effectiveness. However, the limited availability of friction materials, primarily organic polymers, precious metals, and semiconductors, severely hinders the electrical output performance improvement of TENG. In this study, we prepared flexible TENGs using titanium dioxide nanoarrays and four Keplerate-type polyoxometalate (POM) films ({Mo132}, {Mo72Fe30}, {Mo72V30}, and {Mo72Cr30}) as friction materials. POM films were prepared through spin coating on commercial indium tin oxide/poly-(ethylene terephthalate) (ITO/PET) substrates using four different types of POMs. The performance test shows that TENG with {Mo132} (3 mg mL-1)-TNF array as friction material has the best electrical output performance, and the output voltage and current are 26.2 V and 125.4 nA, respectively, which is about 5 times of TENG with Ag-TNF array as friction material. In addition, the mechanism of Keplerate-type POMs as friction materials studied in this paper shows that POMs act as electron acceptors in the friction process and can be used as friction materials, effectively improving the electrical output performance of TENGs and expanding the range of available friction materials. [ABSTRACT FROM AUTHOR]

Self-powered sensors are an important application development direction of nanogenerators. The development of fully self-powered systems that do not rely on traditional energy systems such as mains power or batteries is of great value to the future design of the loT. Such system design is not an easy task due to the detailed calculation of multiple units' energy consumption combined with smart design of minimizing the total consumption of the full system design. By converting energy such as wind energy into electrical energy and designing an indication system that simultaneously utilizes this energy, we completed a fully self-powered sensing system to transduce the wind strength of a high-speed rail. The self-powered sensor part of the system utilizes the modulus design of the pleated elastomer and at the same time achieves wind pressure-LED indication. The circuit is simplified by dropping the traditional control chips, decreasing the energy consumption, and increasing the system reliability. This crumple sensor system has a faster activation speed than that of other wind cup sensors and can sense the wind force when a train passes to protect the canopy structure. This system presents ideas for future designs of fully self-powered systems. [ABSTRACT FROM AUTHOR]

The rapid advancement of nanocomposite materials for coupled triboelectric and piezoelectric nanogenerators (TENG-PENG) has attracted considerable attention due to efficient mechanical energy harvesting in portable and self-powered systems. However, challenges persist due to the nonuniform distribution of guest materials within nanocomposites, resulting in limited surface potential and polarization properties. Here, we demonstrated the incorporation of Nafion into poly-(vinylidene fluoride):lead zirconium titanate (PVDF:PZT) hybrid nanofibers, substantially enhancing the β phase. The surface potential of PVDF:PZT increased to 86 mV, representing a 21% increase over untreated PVDF, while stimulated PVDF:PZT-N hybrid nanofibers show a notable boost of ∼175 mV, increasing to 146% compared to PVDF. The hybrid PVDF:PZT-N exhibits a storage modulus of ∼306 Pa and electrospun hybrid nanofibers displays an elastic limit of ∼1.48 MPa. Furthermore, the efficacy of the PVDF:PZT-N nanofibers is validated through a comparative analysis between engineered single- and double-dielectric layered TENG-PENG devices, producing maximum output currents and voltages of ∼7 μA and ∼40 V, respectively. These TENG-PENG devices have demonstrated their potential to illuminate multiple light-emitting diodes and digital LED display boards. Overall, the incorporation of Nafion into PVDF:PZT nanofibers significantly enhances the output performance of synergistically integrated PENG and TENG systems, offering promising advancements in mechanical energy harvesting and self-powered electronic devices. [ABSTRACT FROM AUTHOR]

The triboelectric nanogenerator (TENG) has been considered as an effective way to convert various mechanical energies into electrical energy. However, the energy output needs continuous improvement for potential applications. In this study, triboelectric layers composed of polyimide (PI) matrix and carbon nanotube@barium titanate (CNT@BTO) nanoparticles were developed to achieve the performance enhancement through the synergistic coupling of piezoelectric and triboelectric effects as well as the microcapacitor function. To achieve the purpose, CNT@BTO nanoparticles were synthesized by the chemical vapor deposition method and then incorporated into a flexible PI triboelectric layer prepared using electrospinning technology and thermal imidization. The results showed that when the BTO content was 26 wt % and the CNT content was 2 wt %, the open-circuit voltage and short-circuit current of a TENG based on a PI/CNT@BTO nanofiber membrane reached 305 V and 104 μA, which were 3 times higher than those of a pure PI-based TENG. The TENG demonstrated sufficient power to drive small electronic devices, such as calculators, and to light up 124 commercial green LED and 18 blue COB light sources. Additionally, the TENG was integrated into a real-time temperature-sensing alarm system, showcasing its potential application in safety-related fields. The study demonstrated the feasible methods for TENGs' performance enhancement and provided potential application fields of energy-harvesting and self-powered sensing systems. [ABSTRACT FROM AUTHOR]

Enhancing the power density of triboelectric nanogenerators (TENGs) poses a significant obstacle to the advancement of self-powered systems. TENGs present numerous advantages such as cost-effectiveness, simplicity in design, and the ability to harness various forms of energy found in nature. Surface modification has emerged as a promising strategy to improve TENG performance, and in this article, an innovative approach is introduced. The ZnO nanosheet surface is modified by synthesizing zeolitic imidazolate framework (ZIF)-8 particles on them and used for TENG fabrication. The TENG devices were constructed using pure ZnO and ZIF-8@ZnO films with poly-(methyl methacrylate) as a fixed opposite triboelectric layer. After introducing ZIF-8 on the surface of ZnO, the output performance of TENG was increased by 1.39 times in terms of output voltage and 1.44 times in terms of output current compared to those of pure ZnO-based TENG. Further, the output power density increased from 455 to 800 mW/m2. In addition to the higher power density, the proposed TENG is demonstrated for powering portable electronic devices and an array of light-emitting diodes. This research opens diverse routes for designing and optimizing TENGs using metal–organic framework (MOF)-modified ZnO nanosheets, thereby advancing self-powered devices and renewable energy technologies. Furthermore, similarly exploring different MOFs holds excellent potential for further enhancing the TENG performance, offering exciting prospects for future developments in this field. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) are capable of sustainably powering wearable sensors by harvesting diverse forms of ambient mechanical energy. Nevertheless, the material and structural designs of friction layers have significant impacts on the performance of TENGs. Electrospun nanofibers can enhance the electrical performance of wearable TENG because of their large specific surface area and porosity. Herein, the free-surface electrospinning technique was used to prepare the positive and negative friction layers with special structures of TENGs. The porous nanofiber membrane (NFM) of polylactic acid (PLA)/chitosan (CS)/aloin with good biocompatibility was used as the positive friction layer of TENGs. Furthermore, a certain amount of carbon black (CB) nanoparticles (NPs) were loaded into thermoplastic polyurethanes (TPU) to prepare beaded NFMs (BNFMs), which helped to improve the hydrophobicity and charge storage capability of the negative friction layer. The morphology of BNFMs with various CB contents and their electrical output performances as negative friction layers were compared, respectively. It was found that the BNFMs could deform under different pressures to enhance the contact area and electrical output of TENG. Moreover, the BNFMs loaded with CB can not only increase their surface roughness but also enhance the charge transfer rate and storage capacity of the friction layer. This provided TENG with good electrical output, high stability, and durability, as well as great application potential in harvesting various types of biomechanical energies. In addition, the proposed all-electrospun TENG had better flexibility, wearing comfort, and fabricating ease, which could be adhered to the human body for sensing human motion when embedded into textiles. [ABSTRACT FROM AUTHOR]

With the rising development of the Internet of Things (IoTs) and artificial intelligence, triboelectric nanogenerators (TENGs) have shown great application potential to dramatically improve our daily lives as self-powered sensors in portable and wearable electronics. In this study, copper foam with graded porous architectures (CFGA), featuring interconnected micro- and nanoporous composite structures, has been developed via a cost-effective and convenient industrial strategy, including electro galvanizing, thermal diffusion, and corrosion methods in sequence. Based on the measurement and evaluation of compressed force, frequency, and reliability, the obtained CFGA can enlarge the contact surface areas and improve the output performance of TENG effectively as a positive electrode. The results show that TENG based on CFGA can yield an open-circuit voltage and a short circuit current of as high as 45.8 V and 1.88 μA, respectively. The corresponding maximum output peak power can reach ∼52.9 μW. For practical application, CFGA-TENG can be designed in a spacer-free structure for keyboards with the function of electronic code lock. Meanwhile, it can also be applied in smart shoe insoles as a self-powered CFGA-TENG sensor array for human motion monitoring in real time. Our work provides an industrial production approach for functional electronics as energy harvesters and sensors and makes it more accessible for practical applications. [ABSTRACT FROM AUTHOR]

Laser-induced graphene (LIG) has aroused a wide range of research interests ranging from micro-nano energy devices to the Internet of Things (IoT). Nevertheless, the non-degradability of most-used synthetic polymer carbon sources poses a serious threat to the environment. In this work, ecofriendly chitosan-based derivatives, including carboxymethyl chitosan (CMCS), chitosan oligosaccharide, and chitosan hydrochloride, are successfully converted into LIGs for the first time via a convenient one-step CO2 laser engraving at ambient air. The obtained LIGs are characterized by a three-dimensional hierarchical porous structure and exhibit good sheet conductivity. The consecutive carbonization and graphitization mechanism of target precursors induced by laser heat accumulation is also deeply discussed. Besides, based on a mechanically reliable LIG/CMCS composite film and tribo-negative acrylic/polyimide anti-layers, two contact-separation mode triboelectric nanogenerators are built and their power densities range from 1.44 to 2.48 mW cm–2. These devices with long cycle life can be used for low-frequency mechanical energy harvesting and commercial capacitance charging, which could be potentially applied in the wireless sensor network nodes. Such a family of chitosan derivatives paves a new route for LIG synthesis and provides new ideas for ecofriendly LIG electronics. [ABSTRACT FROM AUTHOR]

High performance is always the research objective in developing triboelectric nanogenerators (TENGs) for future versatile applications. In this study, a flexible ethyl cellulose/thermoplastic polyurethane (EC/TPU) nanofiber triboelectric layer with barium titanate (BTO) nanoparticles is proposed for high-performance TENGs, in which electrospun EC/TPU nanofiber membranes supply the high-roughness friction surfaces and piezoelectric BTO nanoparticles are further incorporated to boost the electric outputs by the synergistic effect of piezoelectricity and triboelectricity. Consequently, when the content of the BTO nanoparticle is 8 wt % in the EC/TPU (1:4 in weight ratio) nanofibers, the composite membrane displayed a stress of 9.25 MPa and a strain of 275.2%. The corresponding TENG achieves electric outputs of 125.8 V, 34.1 μA, and 1.68 W/m2, much higher than those of an individual piezoelectric nanogenerator or TENG. The TENGs are potentially used to supply energy for commercial LEDs and microelectronics and as self-powered sensors to monitor human physical training conditions. This research provides a guideline for developing TENGs with high performance, which is crucial for their long-term use. [ABSTRACT FROM AUTHOR]

Wearable interactive technology has attracted extensive research interests for future intelligent life. The fast development of the Internet of Things (IoTs) also raises urgent demands on human–machine interaction techniques to provide a direct correlation between human orders and machine operation. Here, we design a series of stereoscopic structured triboelectric nanogenerator (SS-TENG) sensors to be worn on the fingers as a wearable human–robot interactive system. The SS-TENG sensor is designed into a grating-structured TENG (G-TENG) terminally connected with two flap-structured TENGs (F-TENGs). The G-TENG sensor can quantify the bending angle of human finger (minimum resolution of 4.1°) by counting the number of triboelectric signals, while the F-TENG can indicate the bending and holding state of the fingers. Based on the wearable SS-TENG, a manipulator synchronous control system is established to control a robot hand. By counting the number of triboelectric pulses or the positive/negative peaks, an intuitive mapping between the human hand and the manipulator is established. Benefiting from the stereoscopic design, there is plenty of room surrounding the conventional planar TENG device that can be fully utilized to implement more sophisticated triboelectric sensing or interactive applications. [ABSTRACT FROM AUTHOR]

The need for technological innovation in competitive sports is crucial for self-monitoring and smart decision making. In this work, we demonstrate how intelligent sports and smart decision making can be achieved in cricket and boxing using lithium-modified zinc titanium oxide (LZTO) nanofibers based on piezoelectric nanogenerators (PENGs) and triboelectric nanogenerators (TENGs). Zinc titanium oxide (ZTO) nanofibers synthesized using electrospinning followed by a calcination technique are modified with lithium to increase the output of the nanogenerator. An optimized PENG is fabricated using 25 wt % loading of LZTO (d33 = 214 pm/V) in a poly-(vinylidene fluoride) (PVDF) matrix as a double-layered structure and yields an open-circuit voltage (Voc) of 35 V and a short-circuit current (Isc) of 1.6 μA by manual tapping. To fabricate the TENG, Kapton and LZTO are used as negative and positive tribolayers, while Cu and adhesive polymer tape are used as the electrode and spacer, respectively. Furthermore, a hybrid nanogenerator (HNG) is fabricated by combining the PENG and TENG to produce a rectified voltage, current, and power density of up to 75 V, 3.2 μA, and 240 μW/cm2, respectively. These HNGs are integrated with a punching bag and demonstrated to differentiate among the six types of punches in boxing. Furthermore, PENGs are used in cricket to monitor the number of balls middled on the bat during practice and the contact of the ball with the bat and stumps for smart decision making. All kinds of lab-scale testing are done for these applications, which pave a way for exploring the frontiers in nanogenerator applications in sports as maintenance-free and self-powered sensing technology. [ABSTRACT FROM AUTHOR]

Underwater ultrasonic detection is critical for marine security, playing a vital role in resource development, environmental protection, and national defense. However, existing detection systems, which primarily rely on active scanning technologies, are hindered by high costs, significant energy demands, and challenges in achieving large-scale deployment. Here, we introduce a microfiber-based triboelectric acoustic sensor (MTAS) featuring a core-shell hierarchical structure, offering a self-powered solution for precise measurement of underwater ultrasound source distance. By leveraging the principles of contact electrification/triboelectrification and electrostatic induction, the MTAS efficiently converts complex ultrasonic vibrations into real-time electrical signals. The MTAS demonstrates rapid response times as low as 8.6 μs, a high signal-to-noise ratio of 29.8 dB, and the capability to detect ultrasonic sources with power levels above 1.6 W via time-difference-of-arrival analysis. To address large-scale sea applications, we further propose a distributed network that integrates multiple MTAS units capable of precise ultrasonic source localization and real-time motion trajectory visualization. This innovation represents a transformative approach, combining self-powered operation, ease of deployment, and high imperceptibility, paving the way for large-area, energy-efficient submarine security systems. Such advancements redefine the paradigm of underwater target detection, aligning technological innovation with the pressing demands of marine safety and environmental sustainability.

As an innovative renewable energy harvester, the tribovoltaic nanogenerator (TVNG) with lower impedance and DC characteristics has attracted much attention. To alleviate the issues of severe wear for hard-hard semiconductor materials, here, a soft ion dielectric material and semiconductor TVNG based on n-Si/gel polymer electrolyte (GPE) (GPE-TVNG) is proposed. A solid ionic electric double layer (i-EDL) model is established to systematically explore the generation mechanism as well. Moreover, the proposed i-EDL model is verified by subsequent experiments, and the results manifest that the ion directed migration can improve the output performance of GPE-TVNG. The optimized GPE-TVNG has a short-circuit current of 26.5 μA and a low matched impedance of 60 kΩ, which is far lower than the previous reported internal resistance of Si-based TVNG (>100 kΩ). This study broadens the selection of TVNG materials and realizes the effective control of TVNG output.

Metamaterial-based wireless power transfer (MM-WPT) analysis has attracted substantial attention due to its great application potential. However, traditional MM-WPT analysis is constrained by frequency domain approaches which are suitable only for infinitely extended periodic signals or fixed-frequency sine waves but not suitable for complex waveforms of various energy sources. This paper presents an innovative time-domain system analysis method for MM-WPT systems tailored to evaluate energy sources with arbitrary waveforms. The foundation of the method is to use the unit impulse response. By convolving this impulse response with any type of excitation source, a temporal waveform of the voltage across the system's load can be obtained. It has demonstrated a high degree of correlation and agreement between theoretical calculations and experimental results for various input waveforms, affirming its validity, precision, and universality. Based on the framework, it is shown that triboelectric nanogenerators can efficiently self-powered transfer wireless energy through MM-WPT systems. Experiments reveal that the energy received is up to 59.6 times higher compared with that of WPT systems without metamaterials. When this system is applied in an implant, it demonstrates a remarkable energy transfer efficiency of 51% through biological tissues. These findings represent a significant breakthrough in optimizing WPT systems for compact and efficient self-powered energy applications.

Conductive eutectogels have emerged as candidates for constructing functional flexible electronics as they are free from the constraints posed by inherent defects associated with solvents and feeble network structures. Nevertheless, developing a facile, environmentally friendly, and rapid polymerization strategy for the construction of conductive eutectogels with integrated multifunctionality is still immensely challenging. Herein, a conductive eutectogel is fabricated through a one-step dialdehyde xylan (DAX)/liquid metal (LM)-initiated polymerization of a deep eutectic solvent. DAX acts as a stabilizer for the preparation of LM nanodroplets and plays a crucial role in facilitating ultrafast gelation (less than 2 min) by virtue of its reducing dialdehyde groups. Notably, this fabrication strategy obviates the use of toxic chemical initiators and cross-linkers. The resultant eutectogels exhibit extremely high stretchability (2860%), desirable self-healing ability, high conductivity (0.72 S m -1 ), biocompatibility, excellent environmental stability, and exceptional responsiveness to tensile strain (GF = 4.08) and temperature (TCR = 5.35% K -1 ). Benefiting from these integrated features, the conductive eutectogels serve as multifunctional flexible sensors for human motion recognition and temperature monitoring. Furthermore, the eutectogel serves as a pliable electrode in the assembly of a triboelectric nanogenerator (TENG), designed to harvest mechanical energy, convert it into stable electrical outputs, and enable self-powered sensing. This study offers an approach to fabricating multifunctional integrated conductive eutectogels, making it a step closer to the development of intelligent flexible electronics.

Lightweight and robust self-powered wearable devices are of great importance in rehabilitation and medical assistance, but this places greater demands on the development of functional materials. In particular, a balance between reducing the weight of materials and enhancing their mechanical performance is urgently needed. Here, this study reports a design strategy based on a cross-scale strengthening mechanism, which endows triboelectric materials with mechanically robust properties, and can withstand more than 16,600 times its weight without any deformation. A biomimetic ordered network structure with "wall-septum" is obtained by using the directional ice templating method, followed by the formation of more hydrogen bonds between polymer molecular chains promoted by salting-out. The resultant triboelectric material exhibits a Young's modulus of 130.3 MPa, and a specific modulus of 409.0 kN m/kg. Triboelectric materials are used to construct highly robust triboelectric nanogenerators that are stable even under an impact of 735.5 kPa. The accurate acquisition of a human motion state signal in the process of rehabilitation training is realized. This study provides a universal strategy for the development of lightweight and robust triboelectric material and provides a solution for the application of self-powered wearable devices in rehabilitation training.

Chronic kidney disease (CKD) has a high incidence rate, and if not detected and treated in a timely manner, it poses a risk of progressing to renal failure and even uremia. Performing home monitoring of urinary protein, which is a recognized indicator of CKD, is considered an effective means of achieving early warning for CKD. Although the existing urinary protein test strips for home self-testing are cost-effective and simple, they suffer from drawbacks such as susceptibility to contamination and lack of quantitative detection capability. Consequently, they are unable to fulfill the urgent requirement of long-term continuous monitoring. Here, we develop a sensing material that exhibits both colorimetric response for qualitative detection and triboelectric sensitivity for quantitative detection of urinary proteins. Meanwhile, in order to ensure the convenience and accuracy of testing in a home setting, a multichannel portable device that can provide stable mechanical energy input and simultaneously monitor environmental factor has been successfully developed. By utilization of the aforementioned sensing material and device, naked-eye rapid qualitative detection and self-powered quantitative detection of urinary proteins have been achieved. Therefore, this material and device show great potential in the field of home-based urinary protein detection for early warning of CKD.

Triboelectrification-based artificial mechanoreceptors (TBAMs) is able to convert mechanical stimuli directly into electrical signals, realizing self-adaptive protection and human-machine interactions of robots. However, traditional contact-electrification interfaces are prone to reaching their deformation limits under large pressures, resulting in a relatively narrow linear range. In this work, we fabricated mechano-graded microstructures to modulate the strain behavior of contact-electrification interfaces, simultaneously endowing the TBAMs with a high sensitivity and a wide linear detection range. The presence of step regions within the mechanically graded microstructures helps contact-electrification interfaces resist fast compressive deformation and provides a large effective area. The highly sensitive linear region of TBAM with 1.18 V/kPa can be effectively extended to four times of that for the devices with traditional interfaces. In addition, the device is able to maintain a high sensitivity of 0.44 V/kPa even under a large pressure from 40 to 600 kPa. TBAM has been successfully used as an electronic skin to realize self-adaptive protection and grip strength perception for a commercial robot arm. Finally, a high angle resolution of 2° and an excellent linearity of 99.78% for joint bending detection were also achieved. With the aid of a convolutional neural network algorithm, a data glove based on TBAMs realizes a high accuracy rate of 95.5% for gesture recognition in a dark environment.

Polyimide-based triboelectric nanogenerators (TENGs) capable of energy harvesting in harsh environments (high temperature and high humidity) have been extensively studied. However, most polyimide-based TENGs have the disadvantages of poor air permeability and poor softness. In this study, a core-shell yarn with good air permeability, softness, and high electric output performance was successfully prepared by conjugate electrospinning. FEP-doped FPI and nickel-plated aramid yarn were employed as the shell and core materials, respectively. Due to the unique hierarchical porous structure and fluorinated functional group modification, the yarns exhibit excellent output performance (maximum open-circuit voltage is 22.7 V per length of 10 cm) compared to traditional polyimide yarns. The textile woven with this yarn has good high-temperature resistance, antifouling, waterproof, and self-cleaning performance, and still maintains an output performance of about 80% under 99% relative humidity. Moreover, this textile-based TENG has no significant attenuation after 10,000 cycles, showing good stability and durability. Finally, the TENG based on the intelligent fire suit is designed, which can be used for the movement and position monitoring of firefighters in high-temperature and high-humidity environments. This fluorinated polyimide yarn prepared in this study provides a promising solution for the development of self-powered sensors capable of monitoring the movement status and position of firefighters in high-temperature and high-humidity environments.

Aerogels are widely applied for construction, aerospace, military, and energy owing to their lightweight, high specific surface area, and high porosity. The high porosity of aerogels often leads to a lack of mechanical strength, which limits their applications. Here, this study reports a mechanically robust MXene/cellulose nanocrystal composite aerogel enabled by inducing dense bridging through salting-out. First, MXene sheets are bridged with cellulose molecular chains via hydrogen bonds, and further dense bridging is constructed by promoting hydrogen bond formation through salting-out. By enhancing hydrogen bonding, the interlayer spacing of MXene sheets is reduced and their orientation is improved, effectively increasing the energy dissipation capacity of the porous structure. The aerogel exhibits a Young's modulus of 72.4 MPa, a specific modulus of 342.0 kN m/kg. An aerogel is used as a triboelectric material to construct a highly robust triboelectric nanogenerator. This study provides an effective strategy for the preparation of the mechanically robust aerogels.

The urgent need for efficient water energy harvesting has led to the development of triboelectric nanogenerators (TENGs). In this study, considering the droplet spreading dynamics and the capacitive effects in a droplet-driven TENG (DD-TENG) device, an inverse relationship between the width of the top electrode and the output voltage was derived for the first time through a circuit model and was experimentally verified. Additionally, key performance parameters were optimized, including the types and widths of top electrodes, dropping height, inclination angle of the device, and solution types. A nonmonotonic relationship between the inclination angle of the device and the output voltage was established. Under optimal conditions, the output voltage of the DD-TENG achieved a 1133% increase compared to that of the device without a top electrode. The power density reached 1265 mW·m -2 , which is among the state-of-the-art DD-TENG devices. These findings provide valuable insights for the performance improvement of DD-TENGs.

A phosphorus-doped mesoporous carbon (PMC)-filled coating was deposited on polyurethane foam (PUF) via a layer-by-layer assembly method. First, PMC was prepared from bio-sourced saccharose and phytic acid using mesoporous silica KIT-6 as a hard template. The coated PUF was then prepared by alternate dipping into a chitosan (CH) solution and dipping into an alginate-stabilized PMC (AL-PMC) aqueous dispersion. A few layers (three bilayers) of the CH/AL-PMC coating allowed the PUF to self-extinguish when exposed to a butane flame (≈1400 °C). Additionally, this coating layer enabled the foam to pass the UL-94 rating. Cone calorimetry revealed that this coating reduced the peak heat release rate, rate of smoke release, total smoke release, peak CO2 production rate, and peak CO production rate by 56, 48, 29, 35, and 35%, respectively. Using this foam, a flame retardant foam-based triboelectric nanogenerator (FRF-TENG) was fabricated. The FRF-TENG exhibited excellent energy harvesting performance, offering 158 V and 2.26 μA cm–2 open-circuit voltage and short-circuit current density, respectively. Furthermore, the FRF-TENG can be attached on a chair and serve as a self-powered sensor for the detection of back movement and sit-stand motion. This study may provide a promising potential for the design and fabrication of multifunctional smart foams. [ABSTRACT FROM AUTHOR]

As an energy-harvesting device, triboelectric nanogenerators (TENGs) have attracted much attention because they can harvest mechanical energy generated from multiple parts of the human body and easily supply energy to wearable devices. Here, we report a lightweight, portable, and wearable TENG device based on three-dimensional polypyrrole nanoarrays (3D PPy NAs), which can both collect mechanical energy and perform self-powered sensing. 3D PPy NAs were fabricated by a facile electrochemical deposition method using carbon paper as the substrate, and different growth morphologies of PPy NAs were obtained by controlling the deposition time. Among them, the PPy NAs with a deposition time of 1000 s had the largest frictional effective area with the pores of poly-(vinylidene fluoride) (PVDF), and the constructed PPy-PVDF TENG (2 cm × 2 cm) had the highest output performance, with an open-circuit voltage (Voc) of 20.2 V and a short-circuit current (Isc) of 1.3 μA, which are 2.35 and 2.17 times higher than those of the carbon paper TENG (Cp TENG), respectively. In addition, PPy-PVDF TENG can collect mechanical energy from different parts of the human body such as hands, feet, and armpits and realize human motion pattern monitoring and sensing. The device can light up 21 LEDs with the touch of a hand and successfully drive small electronic devices such as a wearable watch and a portable thermohygrometer by integrating the rectifier circuit with a capacitor. This lightweight and portable PPy-PVDF TENG device demonstrates great potential in the field of wearable devices and self-powered sensing. [ABSTRACT FROM AUTHOR]

Combining wearable sensors with modern technologies such as internet of things and big data to monitor or intervene in obesity-induced chronic diseases, such as obstructive sleep apnea, type II diabetes, cardiovascular diseases, and Alzheimer's disease, is of great significance to the self-health management of human beings. This study designed a loofah-conducting graphite four friction layer enhanced triboelectric nanogenerator (LG-TENG) and developed a health management system for human motion recognition and early warning of sleep breathing abnormalities. By uniformly spraying and depositing conductive graphite on the surface of the loofah and the elastic film cross-interlocking bending structure design, the signal strength of the LG-TENG has been improved by 390%. The stable output signal is still maintained after 1500 s of continuous operation at a frequency of 2 Hz. LG-TENG can realize accurate motion analysis by muscle contraction state. Combining different deep learning models resulted in 98.1% accuracy in recognizing seven categories of displacement speeds for an individual and 96.46% accuracy in recognizing seven categories of displacement speeds for three individuals. In addition, the sleep breathing monitoring early warning system was developed by integrating Bluetooth wireless transmission and upper computer analysis technology. This system aims to analyze and provide real-time warnings for sleep-breathing abnormalities. This research promotes an innovation of TENG technology based on the advantages of natural materials, recyclability and low cost. It offers new ideas for self-health management and scientific exercise for obese people, showing a broad application prospect.

Due to their good wearability, smart fabrics have gradually developed into one of the important components of multifunctional flexible electronics. Nevertheless, function integration is typically accomplished through the intricate stacking of diverse modules, which inevitably compromises comfort and elevates processing complexities. The integration of these discrete functional modules into a unified design for smart fabrics represents a superior solution. Here, we put forward a rational approach to functional integration for the typical challenges of thermal management, energy supply, and surface contamination in smart fabrics. This sandwich-structured multilayer fabric (MLF) is obtained by continuous electrospinning of two layer P(VDF-HFP) fabric and one layer P(VDF-HFP) fabric functionalized with core-shell SiO 2 /ZnO/ZIF-8 (SZZ) nanoparticles. Specifically, MLFs achieve effective and stable energy harvesting in triboelectric nanogenerators (TENGs) with hydrophobicity and antibacterial properties. Meanwhile, MLFs also have high mid-infrared emissivity and sunlight reflectivity, successfully realizing radiative cooling under different climates, and have been applied in wearing clothing, roof shading, and car covers. This work may contribute to the design and manufacturing of next-generation thermal comfort smart fabrics and wearable electronics, particularly in terms of the rational design of multifunctional devices.

The conventional behavior recognition strategy for wearable sensors used in high-temperature environments typically requires an external power supply, and the manufacturing process is cumbersome. Herein, we present a rational design strategy based on fully flexible printable materials and a customized device-manufacturing process for skin-conformable triboelectric nanogenerator sensors. In detail, using high temperature-resistant ink and 3D printing technology to manufacture a coaxial triboelectric nanogenerator (C-TENG) sensor, the C-TENG exhibits high stretchability (>400%), a wide working range (>250 °C), and high output voltage (>100 V). The C-TENG can be worn on various parts of the human body, providing a robust skin-device interface that recognizes diverse human behaviors. Using machine learning algorithms, behaviors such as walking, running, sitting, squatting, climbing stairs, and falling can be identified, achieving 100% behavior recognition accuracy through the selective input and optimization of an appropriate dataset. This paper provides a research perspective for the customization, extension, and rapid fabrication of heat-resistant, fully flexible TENGs.

Energy harvesting from ubiquitous natural water vapor based on moisture electric generator (MEG) technology holds great potential to power portable electronics, the Internet of Things, and wireless transmission. However, most devices still encounter challenges of low output, and a single MEG complemented with another form of energy harvesting for achieving high power has seldom been demonstrated. Herein, we report a flexible and efficient hybrid generator capable of harvesting moisture and tribo energies simultaneously, both from the source of water droplets. The moisture electric and triboelectric layers are based on a water-absorbent citric acid (CA)-mediated polyglutamic acid (PGA) hydrogel and porous electret expanded polytetrafluoroethylene (E-PTFE), respectively. Such a waterproof E-PTFE film not only enables efficient triboelectrification with water droplets' contact but also facilitates water vapor to be transferred into the hydrogel layer for moisture electricity generation. A single hybrid generator under water droplets' impact delivers a DC voltage of 0.55 V and a peak current density of 120 μA cm -2 from the MEG, together with a simultaneous AC output voltage of 300 V and a current of 400 μA from the complementary water-based triboelectric generator (TEG) side. Such a hybrid generator can work even under harsh wild environments with 5 °C cold and saltwater impacts. Significantly, an optical alarm and wireless communication system for wild, complex, and emergency scenarios is demonstrated with power from the hybrid generators. This work expands the applications of water-based electricity generation technologies and provides insight into harvesting multiple potential energies in the natural environment with high output.

Emulating biological perception mechanisms to construct intelligent sensing devices and systems represents a paradigm for promoting human-computer interaction in the Internet of Everything era. Nonetheless, developing highly sensitive, real-time sensing and rapidly integrated intelligent interaction units remains a challenging and time-consuming endeavor. This study employs a low-temperature glow discharge technique to rapidly fabricate graded nanotexturing architectural triboelectric nanopaper, upon which wearable triboelectric sensors for real-time tactile detection are designed. The structure enhances the contact area under an external force. Additionally, the Z-stacking structure design enables the sensor to achieve a remarkable sensitivity of 10.3 kPa -1 and a rapid response time of 52 ms. Furthermore, a tactile sensor array was designed to demonstrate the triboelectric sensor's ability to recognize characteristic pressures. With programmable machine learning techniques, the object recognition rate reached 97%. This study supports material structural design across disciplines, laying a solid foundation for the rapid fabrication and integration of transient wearable electronics.

As one of the most important ways of human-machine interfaces, the touchpad has excellent input convenience. Input devices for extreme environments require simpler structures and diverse inputs to ensure information inputs. This paper proposed a self-powered flexible input panel with single-channel output for the input recognition of all 26 letters, and a paper mask was implemented to cover the triboelectric nanogenerator (TENG) board and obtain more complicated electrical signal features. Based on the change of the triboelectric output of the mask, neural network models with different combinations of layers were designed and optimized, and the highest recognition rate of 88.7% for all letters and 100% recognition accuracy for some letters were achieved among the five testers. For letters with low recognition rates, a specific writing specification was further proposed to improve the accuracy of model recognition. These results facilitate the application of the proposed input panel as a flexible wearable device and personal protective equipment for extreme environments including chemical, biological, radiological, nuclear (CBRN) scenarios or aerospace.

As science and technology advance, people are increasingly inclined to use sustainable and portable wearable electronic devices. The traditional supporting power source, batteries, suffers from issues of flexibility and lifespan, severely constraining the development of wearable devices. Alternatively, the self-powered system, serving as a power source, can effectively collect energy from the surrounding environment, achieving maintenance-free operation and high adaptability, which has attracted widespread research. The coaxial fiber-structured self-powering system proposed in this study is based on a supercapacitor (SC) and a triboelectric nanogenerator (TENG). The carbon fiber (CF) has polyaniline (PANI) and rGO connected to it, and a friction layer of silicone rubber is wrapped around the outside. The conductivity of the fiber was increased by multiple PANI graftings, and a coaxial fiber-type TENG with a 2 mm diameter was created. Following weaving, the TENG displays a high power density of 576 mW m -2 and an open-circuit voltage of 160 V and a short-circuit current of 9 μA. In addition, the flexible fiber-shaped supercapacitor uses NiAl-LDHs@CF as the negative electrode and AC@CF as the positive electrode, showing a specific capacitance of up to 281.4 mF cm -2 . Furthermore, the SC and TENG are assembled into a coaxial self-power supply system, which has excellent performance and shows extensive potential applications in the field of wearable device power supply.

Carbon neutrality necessitates new technologies for renewable energy utilization, active regulation of heat exchange, and material recycling to promote green and intelligent building development. Currently, the integration of these functions and characteristics into a single coating material presents a significant challenge. Here, we demonstrate a novel triboelectric and radiative cooling coating with mussel-inspired architectures, fabricated using cellulose nanofibers and Mica-TiO 2 as a functional mortar and brick, respectively. The abundant polar groups and specific surface area of cellulose nanofibers enable a high accumulation of induced electrostatic charges, allowing the coating to act as a tribolayer to generate triboelectric outputs. The regularly layered arrangement of Mica-TiO 2 endows fire resistance to the coating, which exhibits self-extinguishing properties and maintains 45% of its original electrical output even after direct exposure to flame for 20 s. Additionally, the created multilayered stacking morphology, as well as intense group vibrations of Mica-TiO 2 , facilitates high reflectivity ( R solar = 0.9) and long-wave infrared emissivity (ϵLWIR = 0.94), achieving a daytime subambient temperature drop of 5.3 °C. Notably, the coating can be recycled easily while maintaining its triboelectric, radiative cooling, and fire-resistant properties. This work provides an innovative strategy for unifying triboelectric and radiative cooling functions, as well as recyclability, into a single coating material, offering new insights for future sustainable and energy-efficient buildings.

Stretchable, flexible sensors are one of the most critical components of smart wearable electronics and Internet of Things (IoT), thereby attracting multipronged research interest in the last decades. Following miniaturization and multicomponent development of several sensors in one could further propel the demand for wireless, multimodal platforms. Greener substitutes to conventional sensors that can operate in a self-powered configuration are highly desirable in terms of all-in-one sensor utilities. However, fabrication of composite-based ultrastretchable, self-powered sensors with multifunctionality, robustness, and conformability is still only partially achieved and, therefore, demands further investigation. In this work, we report a triboelectric nanogenerator (TENG)-based multifunctional strain and organic vapor sensor using cross-linked ethylene propylene diene monomer (EPDM) elastomer and conducting carbon black as active fillers in the presence of an ionic liquid. The resulting piezoresistive sensor demonstrates ultrahigh gauge factor (GF > 220k) and wide range strain sensitivity and is, therefore, suitable for subtle-to-high frequency motion detection devices. Supported by excellent triboelectric outputs (force sensitivity 0.5 V/N in the range of 50-300 N, maximum output voltage V OC ∼ 178 V, short circuit current I SC ∼ 18 μA, maximum power density 0.11 mW/cm 2 ), the hybrid sensors offer remarkable mechanical toughness and seamless voltage generation under contact-separation, even after several thousand cycles of operations. Furthermore, the sensor substrates exhibited reproducible organic vapor-sensing behavior, with high responsivity of 1.92 and 1 for ethanol and acetone, respectively, under flowing vapor conditions. This work lays a strong foundation for developing a truly multimodal, TENG-based, self-powered organic vapor and strain sensors.

As an emerging high-efficiency energy conversion device, improving the output of triboelectric nanogenerators (TENGs) is still a key method to promote practical application of TENGs. This paper systematically investigated the influence of component composition, thickness, and surface morphology of the metal conducting layer on the performance of triboelectric nanogenerators. It has been established that these three factors have a significant influence on the output performance of TENGs. Among the four common metals Au, Pt, Ag, and Cu, the triboelectric nanogenerator achieves its maximum output when utilizing Ag as the conducting layer, with optimal performance observed at a thickness of 278 nm. TENGs with nanostructured conducting layers have better output as the nanostructure amplifies the induction charging area, thereby effectively augmenting the performance of TENGs. In particular, when contrasted with a triboelectric nanogenerator utilizing copper foil as the conducting layer alongside poly(vinylidene difluoride) and Nylon-11 as friction layers in the common work, the short-circuit current of the triboelectric nanogenerator increased by 2.3 times, and the maximum short-circuit current reached 149 μA when the conducting layer was replaced with Ag, and the enhanced triboelectric nanogenerator successfully illuminated 1536 commercial LEDs. In addition, the TENG-based smart insoles combined with pedometers can realize signal sensing and the real-time recording of steps during exercise. This research provides a new simple and reliable method to further improve the output of the TENG.

Recent advancements in flexible triboelectric nanogenerators (TENGs) have widely focused on converting mechanical energy into electrical energy to power small wearable electronic gadgets and sensors. To effectively achieve this, an efficient energy-converted power management circuit is required. Herein, we report on Aurivillius-type strontium bismuth titanate (SrBi 4 Ti 4 O 15 ) nanoparticles (SBT NPs)-loaded polyglucosamine (PGA) composite film-based flexible TENG to be used for energy harvesting/storage and biomechanical applications. Initially, SBT NPs were synthesized and then, different weight concentrations were loaded into PGA. The TENG devices were fabricated using different wt % composite films (SBT/PGA) and polydimethylsiloxane as positive and negative triboelectric layers, respectively, and aluminum was used as a conductive electrode attached to two tribo films. To evaluate the electrical output from the device, contact-separation operation mode was used. An optimized TENG consisting of 2 wt % SBT/PGA composite film produced the maximum electrical output voltage and current of approximately ∼239 V and ∼7.5 μA, respectively. Efficient TENG energy harvesting and storage circuits have been proposed for storing charges in capacitors and for operating electronic gadgets. The optimized TENG was employed to generate electrical energy from various biomechanical movements. Thereafter, the biodegradability of the composite film was also tested. The fabricated films were completely biodegraded within a few hours. Furthermore, the TENG was utilized as a tap-indication transducer for multipurpose switching applications.

To enhance the adaptability and synergy of the triboelectric nanogenerator (TENG) in a wave environment, this paper introduces a directional adaptive triboelectric nanogenerator (DA-TENG) with wind-water synergistic action for wave energy collection. An innovative design combining a wind vane on the top and fan-shaped blade electrodes internally allows the DA-TENG to adjust its swinging direction adaptively to align with the direction of wave motion. The internal multiple power generation units work in coordination, effectively addressing the issues of low efficiency associated with spherical TENGs in capturing multidirectional wave energy. The DA-TENG demonstrates superior performance under various wind speed conditions, showcasing its practical application potential. Experimental results show that the DA-TENG, equipped with a single tail wind vane and a 700 g mass block, can achieve an output voltage, current, and charge of 374.97 V, 84.77 μA, and 622.69 nC under a mild wind environment. Its peak power density reaches 7.51 W m -3 , enabling successful data transmission for a wireless temperature and humidity sensor and powering 248 light-emitting diodes (LEDs). This research expands the possibilities of omnidirectional wave energy collection and the collaborative operation of multiple power generation units, offering an effective method for powering low-power maritime devices.

Real-time monitoring of UAV motor speed is crucial for enhancing control performance and ensuring flight safety. However, this task faces challenges such as difficult sensor installation and high costs. This study introduces a wireless rotational speed sensing system based on a UAV-rotary triboelectric nanogenerator (UR-TENG). By employing a carefully designed structure with soft contact and a freestanding-triboelectric-layer mode, UR-TENG exhibits characteristics like low friction, affordability, ease of production, and self-powering capability. This eliminates the need for an external power source and addresses the complexity of installation in the limited space of UAVs. Experimental findings demonstrate that UR-TENG possesses high sensitivity and stability, maintaining the structural integrity of the UAV. The goodness of fit is notably high at 0.99959, with a maximum error rate of only 0.014 within a range of 6270 rpm. Moreover, UR-TENG integrates with a microcontroller unit (MCU) and external circuitry to form a monitoring system. This system transmits electrical signals to a PC via a Wi-Fi module, facilitating real-time rotational speed sensing and anomaly detection. Finally, a practical application demonstration on a UAV validates the adaptability of UR-TENG to complex operational environments. This study presents a promising approach for online rotation monitoring of UAV motors, with potential for commercialization, and introduces new avenues for TENG application in UAV technology.

The simultaneous activation of surface lattice oxygen and dioxygen is key to transition metal oxide-based catalytic CO oxidation systems. However, the reaction is difficult at room temperature owing to the high metal–oxygen bond energy. This study presents a triboelectric plasma–transition metal oxide catalytic system driven by a triboelectric nanogenerator, which realizes CO oxidation reaction at room temperature and atmospheric pressure. Among the transition metal oxides evaluated, MnO2 nanostructures exhibited an optimal CO oxidation activity of 0.24 mmol·g–1·h–1 and a low energy consumption converted per mole CO of 6.0 × 103 kJ. For the activation of both surface lattice oxygen and dioxygen, multiple reaction pathways with barriers ranging from 0.37 to 2.43 eV have been revealed by X-ray photoelectron spectroscopy, electron paramagnetic resonance, and density functional theory simulation. These catalytic reaction phenomena have been explained by an extended Mars–van Krevelen mechanism, in which multiple pathways with various barriers were overcome by the electrons in the plasma with a uniform and broad distribution probability. This work provides an efficient strategy for the conversion and utilization of mechanical energy for chemical synthesis. [ABSTRACT FROM AUTHOR]

The energy conversion efficiency of conventional binary dielectric triboelectric nanogenerators is not satisfactory due to the limitations of material selection and triboelectrification, which motivates the design of more efficient multicomponent structures to reveal the charge accumulation mechanism for improving the energy conversion efficiency. Herein, a rotating quaternary dielectric triboelectric nanogenerator (Q-TENG) is designed to construct a self-powered system integrating illumination, sensing, and electrochemical decolorization. Through the equivalent capacitance model, the mechanisms for charge generation, transfer, and accumulation in a Q-TENG are elucidated to achieve efficient matching of quaternary dielectric materials and high output performance. At a wind speed of 3.5 m s -1 , the peak power density of the Q-TENG reaches 44.94 W m -2 , setting a new record for a wind-driven TENG. A 5 ppm solution of methyl orange is completely degraded by the wind-driven Q-TENG in <6 h. This work not only guides the direction for constructing more efficient TENG systems but also promotes the practical development of self-powered electrochemical systems.

For chronic wounds, frequent replacement of bandages not only increases the likelihood of secondary damage and the risk of cross infection but also wastes medication. Therefore, in situ real-time monitoring of the concentrations of residual drugs in bandages is crucial. Here, we propose a novel strategy that combines a triboelectric nanogenerator (TENG) with medical bandages to develop a smart bandage based on zeolite imidazolate framework TENG. During the process of wound healing, the electrical output of TENG changes with the continuous release of drugs. Based on the correlation between the electrical signal of TENG and drug concentration, the concentration of residual drugs in the bandage can be monitored in real-time in situ, guiding medical staff to replace the bandage at the most appropriate time. The smart bandage based on TENG provides a new strategy for in situ real-time monitoring of drug concentration and also provides an ideal and feasible solution for the field of biomedical drug sensing.

The concept of simulating external mechanical stimuli to generate luminescence has been a long-standing aspiration in real-time dynamic visualization. However, creating self-power and self-restoring mechanoluminescent electronic skins for artificial sensors poses significant challenges. In this study, we introduce a cutting-edge triboelectric-mechanoluminescent electronic skin (TMES) that exhibits a remarkable response to multiple external stimuli. This advancement is achieved by integrating a mechanoluminescent intermediate layer within a triboelectric nanogenerator (TENG). When pressure is applied to TMES, the maximum detection voltage can reach hundreds of volts and the maximum correlation sensitivity is 11.76 V/N. Moreover, we incorporate luminescence materials into mechanoluminescence layer, and the maximum absolute sensitivity S R can reach 1.41%. The device can not only distinguish between external stimuli such as pressing and bending but also continuously track external mechanical stimuli. A 4 × 4 matrix and motion prediction of 8 different postures were established to further demonstrate the significant advantages of the developed device in spatial detection. The versatility and performance of the TMES hint at its vast potential in areas such as human-computer interaction and wearable electronics, paving the way for more intuitive and dynamic technological interfaces.

Skin-interfaced wearable sensors can continuously monitor various biophysical and biochemical signals for health monitoring and disease diagnostics. However, such devices are typically limited by unsatisfactory and unstable output performance of the power supplies under mechanical deformations and human movements. Furthermore, there is also a lack of a simple and cost-effective fabrication technique to fabricate and integrate varying materials in the device system. Herein, we report a fully integrated standalone stretchable biophysical sensing system by combining wearable biophysical sensors, triboelectric nanogenerator (TENG), microsupercapacitor arrays (MSCAs), power management circuits, and wireless transmission modules. All of the device components and interconnections based on the three-dimensional (3D) networked graphene/Co 3 O 4 nanocomposites are fabricated via low-cost and scalable direct laser writing. The self-charging power units can efficiently harvest energy from body motion into a stable and adjustable voltage/current output to drive various biophysical sensors and wireless transmission modules for continuously capturing, processing, and wirelessly transmitting various signals in real-time. The novel material modification, device configuration, and system integration strategies provide a rapid and scalable route to the design and application of next-generation standalone stretchable sensing systems for health monitoring and human-machine interfaces.

Triboelectric nanogenerator (TENG) has been demonstrated as a sustainable energy utilization method for waste mechanical energy and self-powered system. However, the charge dissipation of frictional layer materials in a humid environment severely limits their stable energy supply. In this work, a new method is reported for preparing polymer film as a hydrophobic negative friction material by solution blending poly(vinylidene fluoride- co -hexafluoropropylene) (PVDF-HFP) and polyvinyl chloride (PVC), doping with titanium dioxide (TiO 2 ) nanoparticles, and further surface patterning modification. The P-TENG composed of the PVDF-HFP/PVC/TiO 2 composite film with optimized hydrophobic performance (WCA = 124°) achieved an output voltage of 235 V and a short-circuit current of 35 μA, which is approximately three times that of the bare PVDF-HFP-based TENG. Under charge excitation, the transferred charge of the P-TENG can reach 35 nC. When the external load resistance is 5.5 MΩ, the output peak power density can reach 1.4 W m -2 . Meanwhile, the hydrophobic surface layer with a rough surface structure enables the device to overcome the influence of water molecules on charge transfer in a humid environment, quickly recover, and maintain a high output. The P-TENG can effectively monitor finger flexibility and strength and realize real-time evaluation of the exercise state and hand fatigue of the elderly and rehabilitation trainers. It has broad application prospects in self-powered intelligent motion sensing, soft robotics, human-machine interaction, and other fields.

Currently, monitoring the ecological conditions of watercourses is overly unitary and inefficient and is burdened by high costs. A cost-effective, efficient, self-powered sensor for incorporating the Internet of Things (IoT) into the surveillance of riverine ecosystems is lacking. This manuscript introduces a device designed for energy harvesting and sensing through a triboelectric-electromagnetic generator (CX-TEHG). The CX-TEHG is composed of a wind-driven electromagnetic generator (F-EMG), a river-driven electromagnetic generator (W-EMG), a triboelectric nanogenerator for measuring flow velocity (W-TENG), and another triboelectric nanogenerator for gauging the speed of floodwater level rise (F-TENG). It employs planetary gears to achieve a 6-fold increase in speed, facilitating efficient multienergy collection from wind and river currents. CX-TEHG achieves a peak power output of 183 mW and a power density of 373.5 W/m 3 under environmental conditions featuring a wind speed of 4 m/s and a flow velocity of 0.5 m/s. This study developed a cost-efficient signal acquisition system and a mechanism for information transmission via a 5G module. Alerts are issued on both upper-level computers and mobile devices for river flow velocities exceeding 2.8 m/s and water levels reaching specified locations; thus, an innovative solution for applying the Internet of Things in riverine ecological monitoring is presented.

Flexible self-powered tactile sensors, with applications spanning wearable electronics, human-machine interaction, prosthetics, and soft robotics, offer real-time feedback on tactile interactions in diverse environments. Despite advances in their structural development, challenges persist in sensitivity and robustness, particularly when additional functionalities, such as high transparency and stretchability. In this study, we present a novel approach integrating a bionic fingerprint ring structure with a PVDF-HFP/AgNWs composite fiber electrode membrane, fabricated via 3D printing technology and electrospinning, respectively, yielding a triboelectric nanogenerator (TENG)-based self-powered tactile sensor. The sensor demonstrates high sensitivity (5.84 V/kPa in the 0-10 kPa range) and rapid response time (10 ms), attributed to the microring texture on its surface, and exhibits exceptional robustness, maintaining electrical output integrity even after 24,000 cycles of loading. These findings highlight the potential of the microring structures in addressing critical challenges in flexible sensor technology.

Obtaining bioenergy from human movement is not only a prospective complementation to electrochemical power supply such as batteries in portable electronics but also a decipherable process for developing self-powered sensors that can simultaneously monitor the physiological movement. In this study, a low-cost, robust, and environmentally friendly triboelectric nanogenerator (TENG) was prepared with enhanced mechanical stability and tunneling conductivity on the base of cotton fabric. The as-designed TENG may produce energy sustainably by physical movements, and it can yield an amazing 417 V open-circuit voltage, 11.7 μA short-circuit current, and 237.60 mW/m 2 excellent power density, showcasing its potential for efficient energy conversion in the single-electrode mode. Besides, such a design also shows real-time tactile perception ability toward human physiological signal and body motion where intelligent application of these environmental benign TENGs in sports and writing training were demonstrated, thus providing vital instruction for the creation of versatile and sustainable TENGs in the Internet of Things era.

6G communication mainly occurs in the THz band (0.1-10 THz), which can achieve excellent performance. Self-powered THz modulators are essential for achieving better conduction, modulation, and manipulation of THz waves. Herein, a self-powered terahertz modulator, which is based on metamaterials, liquid crystals (LCs), and rotary triboelectric nanogenerators (R-TENGs), is proposed to realize the driving of different array elements. The corresponding designs can achieve an integrated design and preparation method for dynamic spectrum-reconfigurable liquid crystal metamaterials. In addition, for the type of cross-structure metamaterial liquid crystal box, a phase modulation of 1 GHz is achieved at frequencies of 0.117 and 0.161 THz with modulation depths of 13 and 11%, respectively. Because the R-TENG with a multifan blade and circular electrodes can generate 18 peaks of electric output in every rotation, it can successfully provide sufficient frequency alternating-current electric energy to drive the terahertz modulator and achieve a self-powered function. Our findings lay a solid theoretical foundation for further building self-powered THz communication systems and promote the development of a theoretical system for LC-driving spectrum-reconfigurable devices in the THz domain.

Noncontact sensing technology serves as a pivotal medium for seamless data acquisition and intelligent perception in the era of the Internet of Things (IoT), bringing innovative interactive experiences to wearable human-machine interaction perception networks. However, the pervasive limitations of current noncontact sensing devices posed by harsh environmental conditions hinder the precision and stability of signals. In this study, the triboelectric nanopaper prepared by a phase-directed assembly strategy is presented, which possesses low charge transfer mobility (1618 cm 2 V -1 s -1 ) and exceptional high-temperature stability. Wearable self-powered noncontact sensors constructed from triboelectric nanopaper operate stably under high temperatures (200 °C). Furthermore, a temperature warning system for workers in hazardous environments is demonstrated, capable of nonintrusively identifying harmful thermal stimuli and detecting motion status. This research not only establishes a technological foundation for accurate and stable noncontact sensing under high temperatures but also promotes the sustainable intelligent development of wearable IoT devices under extreme environments.