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The demand for non‐invasive health monitoring with wearables poses challenges in developing sustainable, self‐powered systems, as current energy harvesters face issues like complex fabrication, low robustness, and insufficient power density for continuous biosensing. In this study, a wearable self‐powered biosensing platform combining a electromagnetic‐triboelectric hybrid generator (ETHG) with an advanced electrochemical sweat‐ion‐sensing patch is proposed. A Halbach magnet array within the electromagnetic generator (EMG) enhances magnetic flux concentration and power output, while advanced Nylon@polyallylamine and polyvinylidene fluoride@Co3O4 nanofiber films significantly boost the triboelectric generator's performance. Mechanical and theoretical modeling reveals an optimized power output of 328 mW for the EMG and 0.65 mW for the triboelectric component at 6 Hz. This hybrid approach not only enhances the power density but also simplifies the fabrication process and improves the charging performance and robustness of the system. To address potential drift in solid‐contact ion‐selective electrodes, nanoporous carbon ‐modified electrodes increase hydrophobicity, enhancing sensitivity for Na+ (56.1 mV dec−1), K+ (55.2 mV dec−1), and Ca2+ (30.8 mV dec−1), along with excellent performance in pH (69.7 mV dec−1) sensing. Integrating ETHG with a flexible microfluidics‐enabled patch enables real‐time on‐body sweat monitoring, with data wirelessly transmitted via Bluetooth, offering an efficient and robust platform for continuous health monitoring applications. [ABSTRACT FROM AUTHOR]

The triboelectric nanogenerator (TENG) is a promising technology for self‐powered sensors and vibration‐driven energy harvesting, with its development especially influenced by the characteristics of tribomaterials. However, developing tribopositive materials with a strong cationic effect and high electron‐donating capability remains challenging. In this study, a novel polyethylene oxide@poly(diallyldimethylammonium chloride) (PEO@Poly‐DADMAC) composite nanofiber mat (NFM) is successfully fabricated using the electrospinning technique. It functions as a highly tribopositive material, particularly enhancing the performance of nanofiber‐based TENGs (NF‐TENGs). Through investigation of its physical and triboelectric properties, the study revealed that incorporating cationic Poly‐DADMAC with PEO effectively boosts NF‐TENG output by increasing the dielectric constant (twofold), electron‐donating affinities, and surface charge trapping capability. The fabricated NF‐TENG shows excellent output performance generating 980 V, a maximum power density of 5.6 Wm−2, and an ultrahigh sensitivity of 8.923 V kPa−1 which endows composite reliability for power supply and sensing capability. More importantly, the PEO@Poly‐DADMAC‐based self‐powered motion sensor with an NF‐TENG array is successfully demonstrated in multifunctional applications such as athlete activity tracking, and wireless gaming interface control. This study not only offers new insights into optimizing performance and selecting alternative tribomaterials but also provides valuable guidance for developing high‐output TENGs and highly sensitive self‐powered sensors. [ABSTRACT FROM AUTHOR]

The functionality and use of wearable triboelectric nanogenerators (TENGs) are significantly impacted by the development of their tribomaterial properties. Herein, a novel charge‐generating layer (CGL) composed of a V2CTx/Silicone nanocomposite and serpentine TENG (S‐TENG) is introduced. The V2CTx/Silicone nanocomposite exhibits a highly electronegative surface, which significantly enhances the surface potential and charge density. The fabricated nanocomposite‐based TENG exhibits a peak power density of 19.75 W m−2. It also exhibits a high mechanical stretchability (400%), which is significantly better than those of previously reported TENGs under small external pressure. The optimized S‐TENG is demonstrated as a self‐powered human motion sensor with high sensitivity (4.93 V kPa−1) and a quick rise time (21 ms). Furthermore, a real‐life demonstration of sign language interpretation using finger motion detection and text conversion via smartphones is successfully performed. Additionally, the real‐time sensing ability of the S‐TENG is demonstrated in virtual reality car games controlled by finger touch. The S‐TENG is demonstrated to capture different types of human motion energy for continuously powering a stopwatch and wristwatch. Therefore, it is expected that the V2CTx/Silicone nanocomposite will continue with the contributions of novel CGL materials for various TENG applications including wearable self‐powered sensors, robotics, and healthcare monitoring in IoT platforms. [ABSTRACT FROM AUTHOR]

Biomechanical energy harvesting shows great potential in the fields of smart electronics and biomedical Internet of Things. However, it is a significant challenge to develop a biomechanically driven energy harvester with high output power and fast charging as a sustainable power source for extended practical applications. Herein, an ultrahigh‐output triboelectric and electromagnetic hybrid generator (UHO‐TEHG) is developed to efficiently harvest biomechanical energy and provide self‐powered systems for numerous applications. The Halbach magnet array is used to concentrate additional magnetic flux in the coil and significantly enhance electromagnetic performance, while the novel poly(ethylene oxide) nanofibers enhance the triboelectric performance. Through the implementation of a mechanical spring‐mass model, and rational integration of electromagnetic and triboelectric generators, the UHO‐TEHG can provide an excellent output power of 1.02 W. Compared with existing mechanical energy harvesting devices, the fabricated device exhibits a much faster battery charging performance. Experimental results reveal remarkable performance related to biomechanical energy harvesting during walking, running, hiking, mountaineering, and self‐powered wireless human motion sensor. Real‐time charging of smartphones, smartwatches, Buds Live, and iTag via customized power management circuits is demonstrated. In addition, the fabricated UHO‐TEHG demonstrates the capability to power healthcare monitoring systems using a laser‐induced hierarchical carbon nanofiber‐based e‐tattoo sensor. [ABSTRACT FROM AUTHOR]

Self‐powered arbitrary wave monitoring is a hot research topic which aims to remove of the trouble associated with managing conventional power for continuous and real‐time acquisition of wave information from the marine environment. Herein, an effective approach is presented that simultaneously generates power from arbitrary motion waves and can sense and wirelessly transmit the wave information without requiring an external supply. The hybridized ellipsoidal device inspired from an elliptical trajectory of objects over shallow water waves, consists of six planar spiral coils arranged to cover the arbitrary direction of waves for power generation. Four magnetic force‐actuated triboelectric nanogenerators (TENGs) pairs along four sides as the arbitrary direction self‐powered wave motion sensors are integrated. Furthermore, all the required circuitry for signal processing and wireless transmission are integrally powered by the generated electricity to realize a self‐sustained wireless marine environment monitoring system. The generator can deliver peak power of 106 and 44.8 mW (at 3Hz) along with major and minor axis motion directions. The self‐powered sensors have excellent motion sensitivity thus the signals obtained from these sensors are utilized to acquire useful information related to the water waves which are very crucial parameters for real‐time monitoring of the marine environment. [ABSTRACT FROM AUTHOR]

Surface modification of triboelectric negative layers is an essential factor for boosting the output performance of triboelectric nanogenerators (TENGs). Herein, a novel scalable surface modification method is introduced using a fabric‐assisted micropatterning technique on a highly negative MXene/silicone nanocomposite surface (charge generating) with MXene layer (charge trapping) for self‐powered sensors and wearable electronics. The microstructured surface is fabricated directly from a fabric template requiring no surface‐active agent, high‐pressure equipment, or high vacuum. To boost the proposed double‐side‐contact TENG (DSC‐TENG) output performance, different parameters of the fabric textures are tested and optimized for the roughened microstructures, namely the MXene layer and relative humidity. Under optimal conditions, the fabricated DSC‐TENG improves the voltage and peak current density by factors of 9.8 and 20, respectively, regarding flat silicone. It exhibits a maximum peak power density of 55.47 W m−2 at load resistance of 0.18 MΩ, and a corresponding decrease in resistance by 75% using MXene content of 3 mg cm−2. Also, DSC‐TENG‐based smart home control of electrical appliances, theft protection, self‐powered electronic devices, password authentication, and human motion monitoring via smartphone for the IoT are demonstrated. The proposed method can be implemented for different types of polymers, thereby enabling the large‐scale fabrication of high‐performance TENGs in industrial applications. [ABSTRACT FROM AUTHOR]

Hierarchically interactive 3D‐porous soft carbon nanofibers (CNFs) have great potential for wearable bioelectronic interfaces, yet 90% of CNFs are derived from expensive polyacrylonitrile associated with complex production methods. Here, another cost‐effective fluoropolymer, poly(1,1‐difluoroethylene) (PDFE), is introduced to investigate its transition chemistry and structural evolution over laser‐induced carbonization (LIC). The impregnation of Ti3C2Tx‐MXene followed by dehydrofluorination is believed to be crucial to enhance the β‐phase and reinforce PDFE‐based nanofibers. It is explored that the β‐phase of the dehydrofluorinated MXene‐PDFE nanofibers is converted into an sp2‐hybridized hexagonal graphitic structure by cyclization/cross‐linking decomposition during LIC. Remarkably, this approach generates laser‐induced hierarchical CNFs (LIHCNFs) with a high carbon yield (54.77%), conductivity (sheet resistance = 4 Ω sq−1), and stability over 500 bending/releasing cycles (at 10% bending range). Using LIHCNFs, a skin‐compatible breathable and reusable electronic‐tattoo is engineered for monitoring long‐term biopotentials and human–machine interfaces for operating home electronics. The LIHCNFs‐tattoo with high breathability (≈14 mg cm−2 h−1) forms compliant contact with human skin, resulting in low electrode‐skin impedance (23.59 kΩ cm2) and low‐noise biopotential signals (signal‐to‐noise ratio, SNR = 41 dB). This finding offers a complementary polymer precursor and carbonization method to produce CNFs with proper structural features and designs for multifunctional biointerfaces. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs), which operate in contactless mode and avoid physical contact, are highly attractive for self‐powered sensor systems aiming to achieve long‐term reliable operation and reduce rubbing friction. Herein, an ultra‐flexible and high‐performance contactless double‐layer TENG (CDL‐TENG) is first designed and fabricated using a metal–organic framework‐based cobalt nanoporous carbon (Co‐NPC)/Ecoflex with MXene/Ecoflex nanocomposite layer for self‐powered sensor applications. The porous structure of the Co‐NPC provides a high‐surface‐area of the nanocomposite and the charge storage layer of the MXene/Ecoflex nanocomposite accumulates more negative charge to improve the functionality of the CDL‐TENG two and three times, respectively. Compared with Ecoflex film‐based TENGs, the fabricated CDL‐TENG exhibits an eight‐fold slower decay rate owing to charge trapping characteristics, which were confirmed by surface potential measurements. The CDL‐TENG shows excellent humidity and acceleration sensitivity of about 0.3 V/% and 2.06 Vs2 m−1. The CDL‐TENG also offers non‐contact position detection performance in the 20 cm range. Furthermore, the CDL‐TENG is successfully integrated with mobile‐vehicles and an intelligent robot to perform obstacle and human‐motion detection. Finally, a contactless door‐lock password authentication system was demonstrated. These multifunctional benefits make it useful for numerous applications, including artificial intelligence, human‐machine interfaces, and self‐powered sensors. [ABSTRACT FROM AUTHOR]

The triboelectric material properties and mechanical stability of the contact layer are vital to achieving durable triboelectric nanogenerators (TENGs) with high output performance. Herein, a novel MXene/Ecoflex nanocomposite is introduced as a promising triboelectric material because of its highly negative triboelectric properties and mechanical stability. The MXene/Ecoflex nanocomposite with a fabric‐based waterproof TENG (FW‐TENG) is fabricated and designed to universally harvest energy from various human motions as well as the natural environment (rain and wind). The fabricated FW‐TENG delivers a maximum output peak power of 3.69 mW and a power density of 9.24 W m−2, respectively, at a matching load resistance of 4.5 MΩ under a frequency of 4.5 Hz and a force of 8 N. Furthermore, the applicability of this device in various products is investigated. The FW‐TENG can protect against a crash caused by rainy and humid weather. An FW‐TENG‐based self‐powered smart active device that detects motion on a carpet is demonstrated and is equipped with sleep monitoring motion sensors. The FW‐TENG not only has self‐powered benefits and excellent mechanical amenability but is also exceptionally reliable and stable against water intrusion, which are important characteristics to realize next‐generation wearable/portable technologies. [ABSTRACT FROM AUTHOR]

The dynamic behavior of a discrete-time predator-prey system of Leslie type with simplified Holling type IV functional response is examined. We algebraically show that the system undergoes a bifurcation (flip or Neimark-Sacker) in the interior of R+2. Numerical simulations are presented not only to validate analytical results but also to show chaotic behaviors which include bifurcations, phase portraits, period 2, 4, 6, 8, 10, and 20 orbits, invariant closed cycle, and attracting chaotic sets. Furthermore, we compute numerically maximum Lyapunov exponents and fractal dimension to justify the chaotic behaviors of the system. Finally, a strategy of feedback control is applied to stabilize chaos existing in the system. [ABSTRACT FROM AUTHOR]