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Harnessing energy from underwater bubbles has garnered significant attention, particularly for powering off‐grid circuitry. However, the efficiency of bubble‐driven liquid‐solid interface charge transfer remains low. This research unveils a phenomenon: accelerated bubble slippage enhances liquid‐solid interfacial charge transfer. Building upon this discovery, a pulse bubble‐based power generation technique is proposed, achieving an energy density of 24.2 mJ L−1 generated by pulsed bubbles. The crux of pulse bubble power generation lies in the precise control of impact velocity. By meticulously regulating the impact kinetic energy of bubbles, the accumulated potential energy of multiple small bubbles is converted into instantaneous pulse kinetic energy. A typical pulse bubble is controlled within a 72 ms timeframe, unleashing a surge of energy that can directly illuminate 400 light‐emitting diodes. This approach represents a groundbreaking advancement in underwater energy harvesting technology, dramatically expanding its potential applications. [ABSTRACT FROM AUTHOR]

Flexible piezoelectric energy harvesters (FPEHs) have wide applications in mechanical energy harvesting, portable device driving, and piezoelectric sensors. However, the poor output performance of piezoelectric energy harvesters and the intrinsic shortcoming of piezoelectric sensors that can only detect dynamic pressure limit their further applications. BaTiO3 (BT) and PVDF are deposited on the glass fiber electronic cloth (GFEC) by impregnation and spin‐coating methods, respectively, to form BT‐GFEC/PVDF piezoelectric composite films. A mixed solution of mechanoluminescence (ML) particles ZnS:Cu and PDMS are used as the encapsulation layer to construct a high‐performance ML‐FPEH with self‐powered electrical and optical dual‐mode response characteristics. Due to the interconnection structure of the piezoelectric films, the prepared ML‐FPEH illustrates a high effective energy harvesting performance (≈58 V, ≈43.56 µW cm−2). It can also effectively harvest mechanical energy from human activities. More importantly, ML‐FPEH can sense stress distribution of hand‐writing via ML to achieve stress visualization, making up for the shortcomings of piezoelectric sensors. This work provides a new strategy for endowing FPEH with dual‐mode sensing and energy harvesting. [ABSTRACT FROM AUTHOR]

The moisture‐enabled electricity generators (MEGs) represent an appealing clean power strategy within the realm of hydrovoltaic technology. However, their stable operation under all‐weather conditions is still challengeable due to the effect of ambient humidity. Herein, a self‐water‐storage MEGs with multifunctionality was developed. Gel textiles are employed as the proton‐release layer, while graphite fibers loaded with tin‐bismuth alloy liquid metal serve as water‐storing electrode. The gel textiles absorb water permeating down from the electrodes, releasing protons, which then react with the active electrode to enhance output performance. The experiment demonstrates that a device can generate a voltage of 0.55 V and a current of 7.08 μA after water storage, with a maximum power density of 1.14 μW·cm‐². The device's performance output can remain stable within a wide temperature range. The experiment confirms that the electrical output of the device originates from ionic diffusion, while density functional theory (DFT) and molecular dynamics (MD) calculations reveal the importance of the strong hydrolysis ability of the polymer and the high adsorption energy of the liquid metal for H3O+ on the output performance of the device. Furthermore, the integrated device has demonstrated effective applications in driving microelectronic devices, charging capacitors and, self‐powered health monitoring. [ABSTRACT FROM AUTHOR]

In the search for new advanced 2D materials for technological applications and to expand the research of non‐van der Waals (non‐vdW) 2D electronic devices, this study presents a novel strategy for liquid phase exfoliation (LPE) of non‐vdW Cr2S3 to produce Cr2S3 nanosheets (NSs). By utilizing N‐methyl‐2‐pyrrolidone (NMP), bulk Cr2S3 is separated along the (001) plane, resulting in the formation of NSs with an average thickness of ≈3 nm. Various characterization techniques are applied to the Cr2S3 material before and after LPE. Subsequently, the obtained Cr2S3 NSs are integrated into a photoelectrochemical (PEC)‐type photodetector (PD) to evaluate the photoelectric conversion efficiency under varying conditions. The findings indicate that the developed PD exhibits a distinct self‐powered photodetection capability with a photocurrent (Pph) of 39.5 nA cm−2, a photoresponsivity (Rph) of 622 nA W−1, and a detectivity (D*) of 0.5 × 107 Jones under 350 nm irradiation at 0 V. Moreover, the PD demonstrates rapid response time (0.06 s) and good long‐term stability (over 15 days), thus providing valuable insight for the advancement of non‐vdW Cr2S3‐based optoelectronic devices. [ABSTRACT FROM AUTHOR]

Piezoionics, a new frontier that employs mobile ions as energy and charge carriers, plays an important role in new energy and intelligent electronics. However, a significant challenge consists in balancing the structural design of metal ions coordination hydrogel (HG‐MI) piezoionics for current conduction, voltage generation, and especially mechanical adaptability. Herein, inspired by the spider webs' unique structure, a strategy by realizing the full potential of metal‐ligand ions ([(OH)Cl2]3−) to facilitate the keggin‐type structure AlOHAlOH generation together with activate functional carboxyls is introduced. Impressively, the whole property of the product HG‐AlPAC, especially the mechanical performance is improved. For example, the toughness of HG‐AlPAC is 2.75 MJ m−3, more than twofold that of traditional HG‐AlAS/AC/AN samples. Due to the stable fixation of ─Al─OH─ thus promoting Cl− separation upon external force, HG‐AlPAC achieves a piezoionic coefficient of 0.89 mV KPa−1 and energy conversion efficiency of 1.29%, promising for mechanical‐electrical conversion and sensing. Combined with the good mechanical performance with the excellent piezoionic properties, underscores its potential as a tactile nerve system of analgesia patients to prevent them from being injured. This work intends to provide a stride toward mechanically robust self‐powered piezoionic sensors and offer insights into ionotropic materials for energy harvesting, human‐machine interaction, and biointerface. [ABSTRACT FROM AUTHOR]

In the swiftly progressing landscape of wearable electronics and the Internet of Things (IoTs), there is a burgeoning demand for devices that are lightweight, cost‐effective, and self‐powered. In this study, a self‐powered bidirectional knee joint motion monitoring system is introduced, leveraging a dual ratchet sensing (DRS) system fabricated using 3D printing technology. This approach offers substantial economic and portability benefits. The DRS system is engineered to harness the negative work generated from knee joint movements to power commercial electronic devices, obviating the need for additional metabolic energy from the human body. By synergizing the DRS with virtual reality technology, it becomes feasible to monitor knee joint movements in real‐time with remarkable accuracy, presenting a novel avenue for the integration of digital twin technology. Through the amalgamation of convolutional neural network machine learning algorithms with Bayesian optimization techniques, the DRS system can discern up to 97% of knee joint movements, paving the way for innovative applications in smart rehabilitation and healthcare. [ABSTRACT FROM AUTHOR]

Underwater optical communication (UOC) based on the novel photoelectrochemical (PEC) type photodetector has garnered substantial interest in the field of marine resource exploration and ocean investigation due to its strong operability, self‐powered capability, and large sensitive area in harsh underwater environments. To achieve high sensitivity, fast transmission speed, and broadband response characteristics, vertical‐GaS nanosheets‐based PEC photodetectors are prepared by chemical vapor deposition for UOC application. The GaS based PEC photodetector exhibits excellent self‐powered photodetection and a broad UV–vis photoresponse range as well as high stability performance in both Na2SO4 electrolyte and seawater. Notably, it also demonstrates an exceptional photoresponsivity of 11 mA W−1 coupled with a fast response and recovery time of 12.9 and 13 µs which are superior to those of 2D layered materials and conventional wide‐bandgap semiconductors. These improvements are mainly due to the large surface area, short diffusion length, as well as high carrier mobility of vertically‐oriented GaS nanosheets. Strikingly, the constructed GaS photodetector showcases a broad bandwidth exceeding the −3 dB cutoff frequency of 55.3 kHz during UOC testing, successfully enabling transmission and decoding of character information. This work establishes the groundwork for developing high‐performance, self‐powered UV–vis photodetectors adaptable to UOC using PEC technology. [ABSTRACT FROM AUTHOR]

Electric signal accelerates full‐thickness wound healing in the clinic, which is usually generated by a large power generation system and requires delicate control by authorized personnel. Here, a self‐powered flexible and biocompatible thermoelectric device with exceptionally high power generation efficiency is developed. It generates 10 mV voltage at a temperature gradient of 10 K, outperforming all reported flexible thermoelectric devices. Accordingly, it can directly and efficiently convert the omnipresent heat in the skin to electricity at the microvolt level. The output electricity activates and upregulates the expression of Piezo1‐mediated pathways that are associated with tissue regeneration, accelerating the cell migration and proliferation in vitro and healing the wound 4 days faster in vivo. Importantly, the thermoelectric device fast‐heals the wound without involving any additional electric circuit such as an amplifier. These advantages will revolutionize the designing of self‐powered wearable bioelectronics for diagnosing, monitoring, and treating various pathological conditions employing the skin heat. [ABSTRACT FROM AUTHOR]

A new galvanic cell design of a self‐powered and 3D‐printable soft sensor showing health monitoring, object recognition, and contactless hand gesture recognition, is reported. The soft sensor consists of a 3D‐printed poly(acrylic acid) (PAA) hydrogel electrolyte layer, a soft anode layer, and a soft cathode layer. The anode layer is a 3D‐printed and Cu2+ cross‐linked poly(N,N‐dimethylacrylamide‐co‐3‐alanine‐2‐hydroxypropylmethacrylate) (PDA) hydrogel dispersed with Cu metal particles (PDA/Cu2+/Cu hydrogel), while the cathode layer is a bottom thin layer of the PAA hydrogel containing MnO2 (PAA/MnO2). Using graphite films as the soft electrodes, the soft sensor is finally assembled. The soft sensor has high force and temperature sensitivities. It gives different electric current responses under stretching, bending, pressing, and impact loading. The soft sensor is demonstrated to be useful in detecting human motion and physiological activities, e.g., breath. Based on the force and contactless temperature sensitivities, the soft sensor is used to recognize human hand gestures and plastic balls with different diameters. This 3D printable soft sensor with self‐powering, contactless motion capturing, and multi‐pimulus sensing capabilities illustrates a new pathway to make soft sensory devices for healthcare and human‐machine interaction applications. [ABSTRACT FROM AUTHOR]

2D materials with unique layer‐dependent electronic structure can bring precise control to their photocarrier dynamics for optimizing and expanding optoelectronic applications, while the challenge of controlling layer stacking makes the layer dependency law still underexplored in emerging 2D ternary metal chalcogenides. Herein, 2D rhombohedral‐phase ZnIn2S4 (R‐ZIS) with controllable layer thickness is achieved by confined‐growth strategy in high yield, exhibiting continuously tunable direct bandgap (2.39–2.77 eV) with evident upshift of conduction band minimum (CBM) and Fermi level (EF), demonstrated arising from the synergistic effect of reduced interlayer interaction with inevitably increasing Zn defects. Remarkably, the carrier dynamics of R‐ZIS in photoelectrochemical (PEC) device is successfully regulated by adjusted CBM and EF, resulting in continuously tunable optical absorption band, photocarrier separation efficiency, self‐powered capability, and dark current noise. Beneficial from tailored band structure and carrier dynamics, self‐powered PEC‐type photodetector with broadband photoresponse (254–765 nm), is achieved fast response speed (12.3/5.3 ms) and high responsivity (90.29 mA W−1) in multilayer R‐ZIS, while deep‐UV photodetector with ultra‐high specific detectivity (1.62 × 1012 Jones) at 254 nm in monolayer R‐ZIS, exhibiting the record performance in both fields. This work motivates the development of tailored band structure for 2D‐materials‐based optoelectronic devices in strategy and mechanism. [ABSTRACT FROM AUTHOR]

Achieving highly efficient self‐powered fibrous sensing systems is desirable for smart electronic textiles but remains a great challenge. Here, a bifunctional hydrogel is proposed by introducing of polyacrylic acid grafted MXene (MXene‐g‐PAA) into polyacrylamide/chitosan, achieving high‐sensitivity sensor and a stable hydrogel electrolyte of battery. The MXene‐g‐PAA flakes act as ion transport "highway", significantly enhance ionic conductivity, thereby increasing the sensitivity of sensors and facilitating Zn2+ diffusion in Zn‐ion battery (ZIB). The rich hydrogen bonding network in the hydrogel improves its mechanical properties and limits water molecule movement, thus reducing side reactions and prolonging the stability of ZIB. As a result, the fibrous sensor exhibits high strain sensitivity (gauge factor of 2.4) with a wide detection range (0–800%), and the fibrous Zn‐ion battery exhibits high capacity (353 mAh cm−3) with long cycling stability (400 cycles). The hydrogel‐based sensor and ZIB can be easily integrated into a flexible self‐powered sensing system, which effectively detects human movement and 3D ball motion. The bifunctional hydrogel with the integrated fibrous system will shed light on the development of next‐generation smart electronic textiles. [ABSTRACT FROM AUTHOR]

Self‐powered electronic skins (e‐skins), as on‐skin human‐machine interfaces, play a significant role in cyber security and personal electronics. However, current self‐powered e‐skins are primarily constrained by complex fabricating process, intrinsic stiffness, signal distortion under deformation, and inadequate comprehensive performance, thereby hindering their practical applications. Herein, a novel highly stretchable (534.5%), ionic conductive (4.54 S m−1), thermogalvanic (1.82 mV K−1) hydrogel (TGH) is facilely fabricated by a one‐pot method. Owing to the formation of Li+(H2O)n hydration structure, the TGH presents excellent anti‐freezing and non‐drying performance. It remains flexible and conductive (3.86 S m−1) at −20 °C and shows no obvious degradation in the thermoelectrical performance over 10 days. Besides, acting as a self‐powered e‐skin, the TGH combined with deep learning technology for signature recognition and biometric authentication is successfully demonstrated, achieving an accuracy of 92.97%. This work exhibits the TGH‐based e‐skin's tremendous potential in the new generation of human‐computer interaction and information security. [ABSTRACT FROM AUTHOR]

This study presents a method to enhance data processing by integrating a unidirectional analogue artificial neuromorphic memristor device with a piezoelectric nanogenerator, taking inspiration from biological information processing. A self‐powered unidirectional neuromorphic resistive memory device is proposed, comprising an ITO/ZnO/Yb2O3/Au structure combined with a high‐sensitivity piezoelectric nanogenerator (PENG) ITO/ZnO/Al. The memristor device is operated at a voltage sweep of ±4 V with a low operating current in a range of 1.4 µA. The filament formation is studied using a conductive mode atomic force microscope. The integration enables the creation of a self‐powered artificial sensing system that converts mechanical stimuli from the PENG into electrical signals, which are subsequently processed by analogue unidirectional neuromorphic device to mimic the functionality of a neuron without requiring additional circuitry. This emulation encompasses crucial functions such as potentiation, depression, and synaptic plasticity. Furthermore, this study highlights the potential for hardware implementations of neural networks with a weight change of memristor device with nonlinearity (NL) of potentiation and depression of 1.94 and 0.89, respectively, with an accuracy of 93%. The outcomes of this research contribute to the progress of next‐generation low‐power, self‐powered unidirectional neuromorphic perception networks with correlated learning and trainable memory capabilities. [ABSTRACT FROM AUTHOR]

Precision medicine requires precise regulation of drugs in terms of time, space, and dosage. Exogenous control systems, such as electrical responsiveness, have made great progress. However, wearable or implantable controlled drug release devices still face major challenges due to limitations including limited battery life, large size, and fixed power supply. To overcome these limitations, the fabrication of autonomous devices is available to endure extended periods without reliance on external power sources. As a promising strategy, nanogenerators (NGs) turn body mechanical energy into electricity, powering long‐term drug release. In this review, the current status of drug delivery systems (DDS) is briefly outlined and the importance of self‐driven controlled drug release systems is emphasized. The main types and operational mechanisms of various nanogenerators are introduced. This review also focuses on summarizing the latest progress of self‐powered controlled drug release systems based on nanogenerators (NG‐based CDRs). Additionally, their applications in the field of drug release are introduced in detail. Finally, the existing challenges and future trends of self‐powered NG‐based CDRs are discussed from the perspectives of clinical needs and practical translation. [ABSTRACT FROM AUTHOR]

Ultraviolet (UV)‐sensitive semiconductors play a key role in converting UV light into electric signals in a UV photodetector. Two‐dimensional (2D) oxide perovskite, as a kind of green and stable semiconductor materials, exhibits excellent UV detection capabilities. However, the non‐dense nanosheet thin film induces alternative shunts in vertical‐structured devices results in high ohmic leakage currents. Large number of oxygen vacancies in 2D oxide perovskite leads to the adsorption / desorption process of oxygen molecules that slows down the device's response speed. Therefore, an inorganic–organic heterojunction that effectively fills up the pinholes in nanosheet films, effectively suppressing the dark current of the device by 100 000 times are designed. Meanwhile, the construction of inorganic–organic heterojunctions can accelerate the charge carriers' transporting process, resulting in a fast rise / decay response time of 0.7 ms / 8.5 ms. Moreover, the inorganic–organic heterojunction endows the device with excellent self‐powered performance, presenting a high responsivity of 60 mA W−1. This photodetector demonstrates application potential in a UV communication system with a detection angle of 30 degrees and a close‐range communication of 1.2 m. [ABSTRACT FROM AUTHOR]

Material designs for wearable sensors are increasingly important due to variable application scenarios and environmental disturbances. The high temperatures pose a significant challenge to the performance of sensing materials. The reasonable anisotropic structure in materials is recognized as a promising approach to address this challenge. Precise control of the orientation of the material remains difficult, owing to the entropy effect. In this work, a tunable anisotropic triboelectric aerogel via an in situ coupled magnetic alignment and protonation reduction strategy is demonstrated. The designed orientation with a fitting degree of 98% can effectively suppress electron thermionic emission, which enables the surface charge density to reach 75 µC m−2 at 300 °C. Such a perfect coordination between self‐powered sensing and thermostability innovates multifunctional wearable sensing design at high temperatures, allowing aramid‐based aerogel to be a candidate for advanced sensing materials for applications in the military and aerospace fields. [ABSTRACT FROM AUTHOR]

The utilization of unmanned aerial vehicles (UAVs) is on the rise across various industries. In such a scenario, the issue of flight safety for these UAVs becomes increasingly paramount. Currently, UAVs exhibit shortcomings in flight attitude perception compared to more mature manned aircraft, especially concerning the position sensing of flight actuation, which poses significant safety risks. Mature position monitoring solutions for flight actuation used in manned aircraft cannot be directly integrated into systems of UAV due to compatibility issues. This necessitates the development of new position sensing technologies to address this challenge. Triboelectric nanogenerators, with their advantages of miniaturization, self‐powering capabilities, and the ability to generate voltage‐level electrical signals, are chosen to form a part of the position detection system for sensors in UAVs. In this study, a self‐powered displacement sensor is developed that utilizes frictional charge separation signals. This sensor is specifically designed to monitor the position status of the flight actuators in UAV. With a compact volume of <11.1 cm3 and a weight of <9.5 g, this sensor is lightweight efficient and adaptable for practical applications. [ABSTRACT FROM AUTHOR]

A self‐powered and sustainable traffic monitoring system is highly required for future urban development. Herein, self‐healable piezoresistive sensors and triboelectric nanogenerators (TENGs) are constructed by in situ polymerization of polyvinyl alcohol‐polyacrylamide double network hydrogel in the presence of sodium alginate and tannic acid‐modified cellulose nanocrystals (denoted as PPC) for all‐weather self‐powered intelligent traffic monitoring applications. Because of hydrogen bonding and boron ester bonding, the resultant PPC‐based strain sensor can rapidly self‐heal and restore its sensing ability within 1 min with a self‐healing efficiency of 97.4%. Based on piezoresistive effect, the ions in sodium alginate endow the PPC‐based strain sensor with a relatively high gauge factor of 8.39, which can monitor the motion and fatigue of drivers. Based on triboelectrification effect, the PPC‐based TENG sensor can detect instantaneous vehicle speed, judge traffic accident liability, evaluate vehicle weight, and alert the driver to prevent accidents caused by drowsy driving. After partially replacing water in the PPC with glycerin, the resulting PPC‐based TENG sensor exhibits stable performance at temperatures ranging from ‐30 to 40 °C, ensuring its all‐weather monitoring ability. The all‐weather and self‐powered intelligent traffic monitoring system is promising for ensuring the security of future cities. [ABSTRACT FROM AUTHOR]

Anti‐counterfeiting and visual optical information encryption/decryption technology have attracted widespread attention in the field of information security. Luminescent encryption technologies still face a huge challenge in external high voltage power supply, complex architecture, and expensive decryption equipment, which hinder their broad applications. Herein, a wearable integrated self‐powered electroluminescent (EL) display device (W‐ELD) that consists of MXene/Silicone‐based triboelectric nanogenerator (MS‐TENG) and EL device based on a shared MXene electrode is developed for patterned display and information encryption. The W‐ELD features an all‐in‐one MXene electrode with excellent flexibility and high conductivity of 0.6 kΩ sq−1, which is shared by both MS‐TENG and EL devices. The MS‐TENG demonstrates excellent output performances (output power of 0.9 Wm−2) and high stability and durability (104 cycles), which can directly light up the flexible patterned EL device. More importantly, when dripping conductive electrolyte solution, the W‐ELD based on "中國"‐patterned MXene electrode can precisely reveal the encryption information through self‐powered EL emission for real‐time visualized information interaction. Consequently, the all‐in‐one MXene electrode‐based W‐ELD that integrates both MS‐TENG and EL device demonstrates exceptional patterned EL‐based information encryption features, which offers a potential prospect in wearable self‐powered optoelectronic devices, flexible displays, and encryption technology. [ABSTRACT FROM AUTHOR]

Low‐speed flow energy, such as breezes and rivers, which are abundant in smart agriculture and smart cities, faces significant challenges in efficient harvesting as an untapped sustainable energy source. This study proposes an alternating magnetic field‐enhanced triboelectric nanogenerator (AMF‐TENG) for low‐speed flow energy harvesting, and demonstrates its feasibility through experimental results. AMF‐TENG's minimum cut‐in speed is 1 m s−1, thereby greatly expanding its wind energy harvesting range. When the wind speed is 1–5 m s−1, the open‐circuit voltage (VOC) is 20.9–179.3 V. The peak power is 0.68 mW at 5 m s−1. In a durability test of 100 K cycles, the VOC decreases from 188.4 to 174.2 V but remain at 92.5% of the initial value. furthermore, the AMF‐TENG can harvest low‐speed flow energy from the natural environment to power temperature and humidity sensors and wireless light intensity sensor in smart agriculture. This study provides a promising method for low‐speed flow energy harvesting in distributed applications. [ABSTRACT FROM AUTHOR]

Recent advances in organic photodetectors (OPDs) have enabled high detectivity, high quantum efficiency, and fast response, due to their broad spectral response, easy processing, compatibility with flexible devices, and cooling‐free operations. The advantages of combining ultrathin and self‐powered OPDs are rarely explored, as technological limitations and lack of knowledge on the underlying mechanisms may lead to low light absorption efficiency and carrier recombination issues. Here, a modification layer‐assisted approach is developed to construct ultrathin self‐powered OPDs with enhanced sensitivity and ultrafast response time performance due to efficient exciton dissociation, energy transfer, and charge extraction processes. Specifically, this strategy enables a reduced exciton binding energy (42.4 meV) for efficient dissociation, as well as an increased dielectric constant of the photosensitive layer that shields undesirable lattice binding effects of photogenerated excitons. As a result, a remarkable device responsivity (0.45 A W−1), improved response detectivity (1.25 × 1012 Jones), and enhanced energy transfer efficiency (78.7%) are observed in the modified ultrathin organic photodetector. These findings illustrate a clear correlation between the exciton dissociation process, photogenerated exciton yields, and energy transfer channels, providing essential insight into the design of efficient ultrathin organic photodetectors. [ABSTRACT FROM AUTHOR]

Advances in implantable bioelectronics for the nervous system are reinventing the stimulation, inhibition, and sensing of neuronal activity. These efforts promise not just breakthrough treatments of several neurological and psychiatric conditions but also signal the beginning of a new era of computer‐controlled human therapeutics. Batteries remain the major power source for all implanted electrical neuromodulation devices, which impairs miniaturization and necessitates replacement surgery when the battery is drained. Triboelectric nanogenerators (TENGs) have recently emerged as an innovative power solution for self‐powered, closed loop electrical neurostimulation devices. TENGs can leverage the biomechanical activities of different body organs to sustainably generate electricity for electrical neurostimulation. This review features advances in TENGs as they pave the way for self‐sustainable closed loop neurostimulation. A comprehensive review of TENG research for the neurostimulation of brain, autonomic, and somatic nervous systems is provided. The direction of growth of this field, publication trends, and modes of TENG in implantable bioelectronics are also discussed. Finally, an insightful outlook into challenges facing self‐sustainable neuromodulators to reach clinical practice is provided, and solutions for neurological maladies are proposed. [ABSTRACT FROM AUTHOR]

Pyro/piezoelectric effects are thought as essential ways to modulate photoresponses of optoelectronic devices, but the pyro/piezoelectric materials usually function as photoactive or fundamental band matching layers. In this manuscript, a Cu(In,Ga)Se2 (CIGS) multilayer heterojunction of Glass/Mo/CIGS/CdS/ZnO nanowire/ITO is prepared as a self‐powered photodetector (PD). The PD exhibits excellent performances in 405 to 1064 nm with maximum responsivity (R) of 0.455 A W−1, and detectivity (D) of 7.22 × 1011 Jones at zero bias. More importantly, the temperature variation‐induced pyroelectric field in the non‐photoactive ZnO layer is demonstrated to facilitate the transport of carriers. After introducing the pyroelectric effect, the responsivity (R) and detectivity (D) are largely increased to 4.92 A W−1 and 7.81 × 1012 Jones, respectively, and an ultrafast response time of 67.13/78.57 µs is obtained. Meanwhile, the response wavelength is extended to 1550 nm, which is far beyond the spectral limitation of the heterojunction. Besides, the piezoelectric effect of the ZnO nanowire can further optimize the band alignment and then boost the photovoltaic and pyroelectric responses. Owning to the favorable three‐synergistic mechanisms, the best R of 7.22 A W−1 and D of 1.17 × 1013 Jones are observed, which are enhanced by 1586.8% and 1620.5%, respectively, and the response time is also shortened to 50.17/60.65 µs. [ABSTRACT FROM AUTHOR]

Electronic skin (e‐skin), which mimics the tactile perception as human skin, is of interest to advance robotics, prosthetics, and human‐machine interactions (HMI). However, the construction of artificial e‐skin with the simulated function of morphology recognition and stimuli response remains challenging. Here, the design of a multifunctional and self‐powered e‐skin system based on the whisker‐like magnetized micro‐cilia array (MMCA) and the underneath flexible coils is reported. Owing to the excellent flexibility of the MMCA, the adaptive micro‐cilia bending can be produced according to the tactile inputs or surface morphologies. With built‐in magnetic moments, the MMCA deformation thus alters the magnetic flux distribution, which induces an electromotive force (voltage) in the coils for pressure detection and quantitative recognition of micro‐scaled 3D morphologies. It is shown that using the distinct voltage intensities and waveforms, the optimized e‐skin can be applied for real‐time healthcare monitoring, Braille identification, and reconstruction of relief information. By customizing the magnetic moment alignments in MMCA, one e‐skin device can further produce distinguishable signals to build up multi‐commands for efficient HMI, e.g., underwater Morse code communication. Along with temperature tolerance and environmental immunity, the e‐skin exhibits the potential to serve as an effective channel for intelligent 3D topology recognition and high‐capacity communications. [ABSTRACT FROM AUTHOR]

Though visualizing perspiration constituents is crucial for physiological evaluation, inadequate material healing and unreliable power supply methods restrict its applications. Herein, a fully flexible self‐powered sweat sensor is fabricated from a cellulose‐based conductive hydrogel to address these issues. The hydrogel electrode is composed of a cellulose nanocomposite polymerized in situ with polyaniline and cross‐linked with polyvinyl alcohol/borax. The cellulose nanocomposites furnish the sweat sensor with tensile and electrical self‐healing efficiencies exceeding 95% within 10 s, a stretchability of 1530%, and conductivity of 0.6 S m−1. The sweat sensor quantitatively analyzes Na+, K+, and Ca2+ contents in perspiration, to sensitivities of 0.039, 0.082, and 0.069 mmol–1, respectively, in real time via triboelectric effect and wirelessly transmits the results to a user interface. This fabricated sweat sensor with high flexibility, stability, and analytical sensitivity and selectivity provides new opportunities for self‐powered health monitoring. [ABSTRACT FROM AUTHOR]

With perceiving and converting mechanical stimuli into electrical and visual readouts simultaneously, electronic skin endows a safe and effective interaction between human and environment. However, both weak optical signals and low spatial resolution are still challenging the potential application of electronic skin in human–machine information interaction (HMI). Herein, a novel high‐brightness, high‐resolution, and flexible triboelectrification‐induced electroluminescence (TIEL) skin is developed for real‐time imaging and HMI. The TIEL skin composed of ZnS:Cu‐embedded polyvinylidene‐fluoride‐co‐hexafluoropropylene (ZEPH) film can convert gentle touch stimuli into real‐time light emission at trigger pressure threshold as low as 1.25 kPa. Moreover, collected by fiber optic spectrometer, the brightness of TIEL is 2.5 times as strong as an LED lighted up by 2 V power supply. Meanwhile, the bright TIEL emission can also be observed by the naked eyes in the daytime. Furthermore, a spatial resolution of less than 220 µm can be achieved in real‐time TIEL imaging. Additionally, by integrating the ZEPH films with the microcontroller, a wearable optical–electrical dual‐output‐based wireless communication system is constructed to control the trajectory of a miniature car. The unique operation of the desired TIEL with simple fabrication demonstrates a great potential in trajectory tracking, skin prosthesis, robotics, and advanced HMI. [ABSTRACT FROM AUTHOR]

Non‐contact humidity sensors have been widely explored as human–computer interaction for the internet of things and artificial intelligence. However, except for the existing sensing mechanisms, such as resistive, capacitive, and functional groups gradient based device, little attention has been paid to exploiting new sensing mechanisms with novel properties which can meet the requirements of miniaturization and integration. Here, a self‐powered potentiometric humidity‐transduction mechanism, which modulates the measured potential difference between two electrodes by humidity stimulation on the graphene oxide (GO) solid electrolyte, is reported. On the strength of this mechanism, a highly adjustable potentiometric humidity sensor with sandwich structure of reduced graphene oxide/GO/foamed metal (nickel, zinc, iron and copper), exhibiting good scalability and cost‐efficiency, enabling fast response/recovery (0.8 s/2.4 s), ultra‐high response (0.77 V) and excellent stability (over 1500 cycles) is developed. Unlike traditional sensing mechanisms, the manipulation mechanism raised here shows self‐powered ability with no need for an additional power unit and has ultra‐low power consumption. These results provide a new scheme for the research and development of self‐powered humidity sensors, and these sensors show superior performance in non‐contact sensing applications. [ABSTRACT FROM AUTHOR]

Tissue‐like intrinsically stretchable electronics have attracted ever‐increasing study attention in recent years as they can form intimate interfaces with skin, endowing devices monitoring tactile and physiological signals with the negligibly constraining movement of the human body. However, harsh mechanical deformation inevitably leads to degradation of or even destroys the electronic properties of the devices. Strain‐insensitive self‐powered triboelectric tactile sensor arrays based on wafer‐scale patterned and intrinsically stretchable nanoscale thin conformal wrinkled graphene‐elastomer composite material are demonstrated here. By regulating the wrinkle structure of the composite, the stretchability performance of the material can be optimized. The fabrication process of the composite can be readily incorporated into photolithography and shadow mask techniques without high temperature, annealing, etching, or organic solvents operating. An intrinsically stretchable semitransparent pressure sensor array is created, which can be stretched to 100% strain without visible signals output degradation. The theoretical modeling points out that the unique conformal wrinkle structure is the key element that attributes to the strain‐insensitive property of the device. This work offers an alternative approach for the design of novel graphene‐based strain‐insensitive stretchable soft electronic devices. [ABSTRACT FROM AUTHOR]

Self‐powered perovskite X‐ray detectors have drawn increasing attention due to the merits of low noise, low power consumption as well as high portability and adaptability. However, the active layer thickness is usually compromised by the small carrier diffusion length, which leads to inefficient X‐ray attenuation and hence low sensitivity of the detectors. Herein, self‐powered and highly sensitive single‐crystal perovskite X‐ray detectors are achieved by finely controlling the crystal thickness and optimizing their carrier transport properties. Perovskite single crystals with thickness of around 800 µm are grown by a two‐step crystal growth process to realize the full attenuation of hard X‐ray with the energy of 80 keV. And the incorporation of formamidinium (FA) (FA = CH(NH2)2+) cation into methylammonium lead triiodide (MAPbI3) (MA = CH3NH3+) increases the mobility‐lifetime (µτ) product of the single crystals by nearly one order of magnitude, leading to a record X‐ray detection sensitivity of 8.7 × 104 µC Gyair−1 cm−2 under zero bias. Moreover, the eliminated external bias and reduced trap density weaken the field‐driven ion migration effect, and therefore result in a low detection limit of 27.7 nGy s−1. This work represents an effective way to achieve self‐powered perovskite X‐ray detectors with both high sensitivity and low detection limit. [ABSTRACT FROM AUTHOR]

Multiple‐band and spectrally distinctive photodetection play critical roles in building next‐generation colorful imaging, spectroscopy, artificial vision, and optically controlled logic circuits of the future. Unfortunately, it remains challenging for conventional semiconductor photodetectors to distinguish different spectrum bands with photon energy above the bandgap of the material. Herein, for the first time, a photocurrent polarity‐switchable photoelectrochemical device composed of group III‐nitride semiconductors, demonstrating a positive photocurrent density of 10.54 µA cm−2 upon 254 nm illumination and a negative photocurrent density of −0.08 µA cm−2 under 365 nm illumination without external power supply, is constructed. Such bidirectional photocurrent behavior arises from the photovoltage‐competing dynamics across two photoelectrodes. Importantly, a significant boost of the photocurrent and corresponding responsivity under 365 nm illumination can be achieved after decorating the counter electrode of n‐type AlGaN nanowires with platinum (Pt) nanoparticles, which promote a more efficient redox reaction in the device. It is envisioned that the photocurrent polarity‐switch behavior offers new routes to build multiple‐band photodetection devices for complex light‐induced sensing systems, covering a wide spectrum band from deep ultraviolet to infrared, by simply engineering the bandgaps of semiconductors. [ABSTRACT FROM AUTHOR]

Traditional topical ointment applied on the skin surface has poor drug penetration due to the thickening of the stratum corneum for psoriasis. Microneedles (MNs) provide a desirable opportunity to promote drug penetration. However, the common MNs are difficult to meet the requirement of on‐demand drug delivery. In this study, a smart electrical responsive MNs is fabricated by introducing conductive material of polypyrrole (PPy). Further, a self‐powered controllable transdermal drug delivery system (sc‐TDDS) based on piezoelectric nanogenerator (PENG) is developed. The sc‐TDDS can control drug release by collecting and converting mechanical energy into electrical energy. The sc‐TDDS can release 8.5 ng dexamethasone (Dex) subcutaneously per electrical stimulation. When treating psoriasis‐like skin disease with sc‐TDDS, the inflammatory skin returned to normal after 5 days, which is obviously better than treating with traditional Dex solution coating. This work provides a promising approach of on‐demand transdermal drug release for various disease treatment scenarios. [ABSTRACT FROM AUTHOR]

The rapid development of electronic skins has allowed novel multifunctional human–machine interaction interfaces, especially in motion interaction sensors. Although motion sensing is widely used in advanced flexible electronic devices through the integration of single sensing units, the number of electrodes has increased with the increase in integration by the square multiple. This paper presents a self‐powered electronic skin based on the Archimedes spiral structure design, which can detect the multi‐directional movement of the slider without external energy supply. As the rotation angle of the Archimedes spiral increases from 2π to 4π, the maximum resolvable movement direction of the device increases from 24 to 280, and the number of electrodes is kept at 4. Through the exploration of the principle of triboelectricity, the inherent electronegativity of the triboelectric materials is used as the basis for signal discrimination, which not only increases the reliability of the device, but also solves the problem of energy supply during device operation. A reduced number of electrodes and its battery‐free nature enables this electronic skin to be easily integrated into portable electronic devices, such as laptops, smart phones, healthcare devices, etc. [ABSTRACT FROM AUTHOR]

A useful direction to solve the energy problem is the effective repeated use of biomaterial for mechanical energy collection and sensing applications. Here, a feather‐based single‐electrode triboelectric nanogenerator (F‐STENG) by only sputtering copper atoms on the feathers are presented. The feather of F‐STENG, as a natural material, has environmental friendliness, which is different from the polymer materials of other triboelectric nanogenerators. F‐STENG has super durability due to its feather structure self‐healing property. The device has a high output voltage of 90 V and an output current of 3.5 µA. After breaking and self‐healing lots of times, the output performance is also 80% of the original. F‐STENG has a high sensitivity to temperature, humidity, and wind speed, and the sensitivity is 0.50 V °C−1, ‐0.98 V RH−1, and 1.67 μA m−1 s−1. The output power of F‐STENG is 0.62 mW g−1, which can realize global positioning and photographing to solve the module energy consumption problem. F‐STENG provides an effective way for the application of self‐powered sensors and equipment in military, industrial, transportation, and daily life. [ABSTRACT FROM AUTHOR]

Multifunctional sensors that can simultaneously detect light and thermal stimuli play an essential role in the research of portable devices and complex arrays of electronics. Lots of effort has been made to realize the simultaneous detection of light and temperature in a standalone device. However, since there is a strong interference of electric signals, accurate simultaneous sensing remains a challenge. Here, a self‐powered dual‐parameter sensor based on thermo‐phototronic effect in Nb‐doped SrTiO3 (NSTO) single crystal to achieve decoupled light and temperature sensing is developed. High light‐ and temperature‐sensing sensitivities of 0.201 µA mW cm−2 and 16.77 µA K−1 are realized, respectively. The excellent simultaneous sensing capability may be attributed to effective light‐to‐electrical and thermal‐to‐electrical energy conversion in the NSTO crystal. The excellent simultaneous sensing performance of the dual‐parameter sensors, together with their ease of fabrication, pushes forward the development of highly sensitive multifunctional sensors. [ABSTRACT FROM AUTHOR]

The blind mainly relies on Braille books to obtain text information. However, Braille books with invariable content are ponderous and inconvenient to read. Hence, it is essential to find a safe, simple and effective method to develop new Braille devices. This advanced method promises to be the next generation Braille book that is refreshable, flexible, and portable. Therefore, a safe dielectric elastomer Braille device actuated by a triboelectric nanogenerator is designed. It is easy to fabricate, inexpensive, and safe without any potential hazard for blind people. For triboelectric nanogenerators, the friction between two thin films can generate a voltage over 3 kV with a current of just 2 µA to deliver a shape change of the dielectric elastomer membrane. In the meantime, with the support of the pressor air in the chamber, the membrane will be raised up to be a touchable Braille dot. In addition, a programmed switch matrix is designed to control the Braille device with multiple dielectric elastomer dots to realize complicated refreshable display, providing a possibility of a page‐size and portable braille e‐book for the blind in the near future. [ABSTRACT FROM AUTHOR]

Accompanying the boom in multifunctional wearable electronics, flexible, sustainable, and wearable power sources are facing great challenges. Here, a stretchable, washable, and ultrathin skin‐inspired triboelectric nanogenerator (SI‐TENG) to harvest human motion energy and act as a highly sensitive self‐powered haptic sensor is reported. With the optimized material selections and structure design, the SI‐TENG is bestowed with some merits, such as stretchability (≈800%), ultrathin (≈89 µm), and light‐weight (≈0.23 g), which conformally attach on human skin without disturbing its contact. A stretchable composite electrode, which is formed by homogenously intertwining silver nanowires (AgNWs) with thermoplastic polyurethane (TPU) nanofiber networks, is fabricated through synchronous electrospinning of TPU and electrospraying of AgNWs. Based on the triboelectrification effect, the open‐circuit voltage, short‐circuit current, and power density of the SI‐TENG with a contact area of 2 × 2 cm2 and an applied force of 8 N can reach 95 V, 0.3 µA, and 6 mW m−2, respectively. By integrating the signal‐processing circuits, the SI‐TENG with excellent energy harvesting and self‐powered sensing capability is demonstrated as a haptic sensor array to detect human actions. The SI‐TENG exhibits extensive applications in the fields of human–machine interface and security systems. [ABSTRACT FROM AUTHOR]

Electric devices has become a necessity in modern smart societies. The energy research community is continually exploring new solutions that can be employed as potential and reliable alternatives to satisfy future energy requirements in this context. Triboelectric/piezoelectric nanogenerators (TNGs/PNGs) are considered promising renewable energy harvesting technologies. TNGs/PNGs are gaining considerable research attention because of their advantages such as ease of fabrication, cost effectiveness, flexibility, lightweightness, long‐term‐durability, and excellent output performance. The TNGs/PNGs have enormous potential in harvesting energy from water waves (blue energy), airflow (wind energy), sound frequency (acoustic energy), vibrations/mechanical motions (such as body motions activities/sleeping), and in vivo body motions. These technologies are thus an "all‐in‐one package," which is a unique selling point. The advantage of this technology is that all sources are natural and abundant. This paper provides a review of the potential use of PNGs/TNGs and includes a description of the rise of nanogenerators, their underlying mechanisms, different materials used, various models, possible applications, and future prospects. Stored energy can be used to develop smart/informative technologies (as ultrasensitive sensors) and self‐powered biomedical science. Owing to their considerable effects, these harvesting technologies are expected to dominate the future smart world. [ABSTRACT FROM AUTHOR]

A novel inorganic–organic heterojunction (TiO2/P3HT (poly(3‐hexylthiophene)) is easily prepared by a combination of anodization and vacuumed dip‐coating methods, and the constructed flexible fibrous photodetector (FPD) exhibits high‐performance self‐powered UV–visible broadband photoresponse with fast speed, high responsivity, and good stability, as well as highly stable performance at bending states, showing great potential for wearable electronic devices. Moreover, Au nanoparticles are deposited to further boost the responsivity and selectivity by regulating the sputtering intervals. The optimal Au/TiO2/P3HT FPD yields an ≈700% responsivity enhancement at 0 V under 350 nm illumination. The sharp cut‐off edge and high UV–visible rejection ratio (≈17 times higher) indicate a self‐powered flexible UV photodetector. This work provides an effective and versatile route to modulate the photoelectric performance of flexible electronic devices. [ABSTRACT FROM AUTHOR]

The traditional photodetectors based on photoelectric effect exhibit inferior response or even out of operation with the decrease of temperature. However, cryogenic visible light detection is increasingly demanded in deep space and polar exploration. Herein, a self‐powered visible photodetector coupling pyroelectricity and photoelectricity to optimize the cryogenic detecting performance is designed in which hydrothermally grown CdS nanorod array is covered by SnS nanoflakes. The choice of SnS allows the detector with strong visible light absorption and great photoelectric conversion efficiency, while the CdS nanorod structure with pyroelectricity can effectively modulate the behavior of photogenerated carriers at low temperatures. It is found that the response characteristics of the photodetector are dominated by the combination of pyroelectric and photoelectric effects, which becomes more significant with the reduced temperature. Specifically, at 130 K temperature, the photoresponse current under 650 nm light is improved by 7.5 times as that at room temperature, while the ratio of pyroelectric current to photocurrent can be increased to 400%. Meanwhile, the responsivity and detectivity are as high as 10.4 mA W−1 and 3.56 × 1011 Jones, respectively. This work provides a promising approach to develop high‐performance self‐powered visible photodetectors with low‐temperature operating capability. [ABSTRACT FROM AUTHOR]

Self‐powered perovskite photodetectors mainly adopt the vertical heterojunction structure composed of active layer, electron–hole transfer layers, and electrodes, which results in the loss of incident light and interfacial accumulation of defects. To address these issues, a self‐powered lateral photodetector based on CsPbI3–CsPbBr3 heterojunction nanowire arrays is designed on both a rigid glass and a flexible polyethylene naphthalate substrate using an in situ conversion and mask‐assisted electrode fabrication method. Through adding the polyvinyl pyrrolidone and optimizing the concentration of precursors under the pressure‐assisted moulding process, both the crystallinity and stability of perovskite nanowire array are improved. The nanowire array–based lateral device shows a high responsivity of 125 mA W−1 and a fast rise and decay time of 0.7 and 0.8 ms under a self‐powered operation condition. This work provides a new strategy to fabricate perovskite heterojunction nanoarrays towards self‐powered photodetection. [ABSTRACT FROM AUTHOR]

BiFeO3 (BFO) is a potentially important Pb‐free ferroelectric with a narrow bandgap and is expected to become a novel photodetector. The photocurrent in BFO3 strongly depends on the temperature but only a few studies have investigated in detail the relationships between photocurrent and temperature. Here, the temperature‐dependent photocurrent and the corresponding photosensing properties of a Ag/BFO/indiumtin oxide (ITO) photodetector based on an optimized planar‐structured electrode configuration are investigated. The photocurrent and responsivity of the BFO3‐based photodetector can first be increased and then be decreased with increasing temperature. The largest photocurrent and responsivity can reach 51.5 µA and 6.56 × 10−4 A W−1 at 66.1 °C, which is enhanced 126.3% as compared with that at room temperature. This may be caused by the temperature‐modulated bandgap and barrier height in Ag/BFO/ITO device. This study clarifies the relationship between photosensing performance and the operating temperature of BFO‐based photodetector and will push forward the application of ferroelectric materials in photoelectric field. [ABSTRACT FROM AUTHOR]

Abstract: A new self‐powered brain‐linked vision electronic‐skin (e‐skin) for mimicking retina is realized from Polypyrrole/Polydimethysiloxane (Ppy/PDMS) triboelectric‐photodetecting pixel‐addressable matrix. The e‐skin can be driven by human motion, so no external electricity power is needed in both photodetecting and signal transmitting processes. The triboelectric output is significantly dependent on the photo illumination, which can act as visual bionic electric impulse. Taking blue illumination (405 nm) as an example, as the e‐skin is exposed to 100 µW cm−2 illumination, the output current decreases from 7.5 to 4.9 nA, and the photosensitivity is 34.7. And the photosensitivity of the e‐skin keeps stable with different bending angles and force. The e‐skin is flexible enough to combine with human body and can be driven by blinking eyes to detect UV illumination. In addition, the 4 × 4 photodetecting unit matrix in the e‐skin can map single‐point and multipoint illumination‐stimuli (visual‐image recognition) via the multichannel data acquisition method. Furthermore, the e‐skin can directly transmit photodetecting signals into mouse brain for participating in the perception and behavior intervention. This new self‐powered perception device can lower down the production cost of traditional complex sensory‐substitution system, and can be easily extended to various brain–machine interaction applications. [ABSTRACT FROM AUTHOR]

Abstract: The development of new flexible and stretchable sensors addresses the demands of upcoming application fields like internet‐of‐things, soft robotics, and health/structure monitoring. However, finding a reliable and robust power source to operate these devices, particularly in off‐the‐grid, maintenance‐free applications, still poses a great challenge. The exploitation of ubiquitous temperature gradients, as the source of energy, can become a practical solution, since the recent discovery of the outstanding thermoelectric properties of a conductive polymer, poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS). Unfortunately the use of PEDOT:PSS is currently constrained by its brittleness and limited processability. Herein, PEDOT:PSS is blended with a commercial elastomeric polyurethane (Lycra), to obtain tough and processable self‐standing films. A remarkable strain‐at‐break of ≈700% is achieved for blends with 90 wt% Lycra, after ethylene glycol treatment, without affecting the Seebeck voltage. For the first time the viability of these novel blends as stretchable self‐powered sensors is demonstrated. [ABSTRACT FROM AUTHOR]

Converting environmental 'waste energies' into electricity via a natural process is an ideal strategy for environmental energy harvesting and supplying power for distributed energy-consuming devices. This paper reports that evaporation-driven water flow within an all-printed porous carbon film can reliably generate sustainable voltage up to 1 V with a power density of ≈8.1 µW cm−3 under ambient conditions. The output performance of the device can be easily scaled up and used to power low-power consumption electronic devices or for energy storage. Furthermore, the device is successfully used without electric storage as a direct power source for electrodeposition of silver microstructures. Because of the ubiquity of water evaporation in nature and the low cost of materials involved, the study presents a novel avenue to harvest ambient energy and has potential applications in low-cost, green, self-powered devices and systems. [ABSTRACT FROM AUTHOR]

Large-size 2D black phosphorus (BP) nanosheets have been successfully synthesized by a facile liquid exfoliation method. The as-prepared BP nanosheets are used to fabricate electrodes for a self-powered photodetector and exhibit preferable photoresponse activity as well as environmental robustness. Photoelectrochemical (PEC) tests demonstrate that the current density of BP nanosheets can reach up to 265 nA cm−2 under light irradiation, while the dark current densities fluctuate near 1 nA cm−2 in 0.1 M KOH. UV-vis and Raman spectra are carried out and confirm the inherent optical and physical properties of BP nanosheets. In addition, the cycle stability measurement exhibits no detectable distinction after processing 50 and 100 cycles, while an excellent on/off behavior is still preserved even after one month. Furthermore, the PEC performance of BP nanosheets-based photodetector is evaluated in various KOH concentrations, which demonstrates that the as-prepared BP nanosheets may have a great potential application in self-powered photodetector. It is anticipated that the present work can provide fundamental acknowledgement of the performance of a PEC-type BP nanosheets-based photodetector, offering extendable availabilities for 2D BP-based heterostructures to construct high-performance PEC devices. [ABSTRACT FROM AUTHOR]

A new flexible smelling electronic skin (e-skin) has been realized from PANI(polyaniline)/PTFE(polytetrafluoroethylene)/PANI sandwich nano­structures basing on the triboelectrification/gas-sensing coupling effect. The e-skin can be driven by human motion/breath and efficiently convert mechanical vibration into electric impulse. And the output current/voltage is significantly dependent on the environmental atmosphere (volatile organic compounds in air), which can act as olfactory bionic electric impulse. Taking ethanol gas as an example, the detection limit of the e-skin at room temperature is 30 ppm, and the response is up to 66.8 upon exposure to 210 ppm ethanol. Interestingly, the response of the e-skin keeps stable with different dimensional sizes or under different strains/bending status. The working mechanism can be ascribed to the coupling of triboelectrification effect and surface reaction at the interfaces. Furthermore, an application of the flexible smelling e-skin for visually identifying drunken driver without any external electricity power has been demonstrated. The results can open a possible new direction for the development of specialized-function e-skin and will further expand the scope for self-powered nanosystems. [ABSTRACT FROM AUTHOR]

A novel self-recovering triboelectric nanogenerator (STENG) driven by airflow is designed as active multifunctional sensors. A spring is assembled into the STENG and enables the nanogenerator to have self-recovering characteristic. The maximum output voltage and current of the STENG is about 251 V and 56 μA, respectively, corresponding to an output power of 3.1 mW. The STENG can act as an active multifunctional sensors that includes a humidity sensor, airflow rate sensor, and motion sensor. The STENG-based humidity sensor has a wide detection range of 20%-100%, rapid response time of 18 ms, and recovery time of 80 ms. Besides, the STENG could be utilized in the application of security monitoring. This work expands practical applications of triboelectric nanogenerators as active sensors with advantages of simple fabrication and low cost. [ABSTRACT FROM AUTHOR]

The rapid development of electrical skin and wearable electronics raises the requirement of stretchable strain sensors. In this study, an active fiber-based strain sensor (AFSS) is fabricated by coiling a fiber-based generator around a stretchable silicone fiber. The AFSS shows the sensitive and stable performance and has the ability to detect the strain up to 25%, which is also demonstrated to detect finger motion states. It may play an essential role in future self-powered sensor system. [ABSTRACT FROM AUTHOR]

A new membrane-based triboelectric sensor (M-TES) is presented as a self-powered pressure change sensor. It generates a voltage induced by surface triboelectric charges in response to an air pressure change. Extremely high detection resolutions of 0.34 Pa and 0.16 Pa are achieved when the air pressure increases and decreases in a small region away from the ambient standard atmosphere pressure, respectively, indicating an excellent sensitivity. By integrating the M-TES with a signal processing unit, we demonstrate practical applications of the device in sensing footsteps, respirations, and heartbeat, which suggests widespread use of the M-TES in fields of security surveillance, chemical engineering, geography research, environment monitoring, and personal healthcare. [ABSTRACT FROM AUTHOR]

A self-powered, piezotronic effect-enhanced glucose sensor based on metal-semiconductor-metal (M-S-M) structured single ZnO nanowire device is demonstrated. A triboelectrical nanogenerator (TENG) is integrated to build a self-powered glucose monitoring system (GMS) to realize the continuously monitoring of glucose concentrations. The performance of the glucose sensor is generally enhanced by the piezotronic effect when applying a -0.79% compressive strain on the device, and magnitude of the output signal is increased by more than 200%; the sensing resolution and sensitivity of sensors are improved by more than 200% and 300%, respectively. A theoretical model using energy band diagram is proposed to explain the observed results. This work demonstrates a promising approach to raise the sensitivity, improve the sensing resolution, and generally enhance the performance of glucose sensors, also providing a possible way to build up a self-powered GMS. [ABSTRACT FROM AUTHOR]