Publications

Abstract Triboelectric nanogenerator (TENG) devices are extensively studied as a mechanical energy harvester and self‐powered sensor for wearable electronics and physiological monitoring. However, the conventional TENG fabrication involving assembling steps and using the single property of matrix material suffers from simple devices shape and a single level of mechanical response for sensing and energy harvesting. Here, the printed multimaterial matrix for multilevel mechanical‐responsive TENG with on‐demand reconfiguration of shape is reported. A multimaterial 3D printing approach by using dynamic photomask‐assisted direct ink writing printing together with a two‐stage curing hybrid ink is first developed. Multimaterial structures with location‐specific properties, such as tensile modulus, failure stress, and glass transition temperature for controlled deformation, crack propagation path, and sequential shape memory, are directly printed. The printed multimaterial structure with sequential deformation behavior is used to fabricate a multilevel‐TENG (mTENG) device for multiple level mechanical energy harvesters and sensors. It is demonstrated that the mTENG can be embedded in shoe insoles to achieve both comfortable wearing and motion state monitoring. This work provides a new approach to combine multimaterial 3D printing with TENG devices for functional wearable electronics as energy harvester and sensors.

K. J. Lee and co-workers demonstrate the fabrication of a flexible nanocomposite generator using piezoelectric BaTiO3 nanoparticles and universal graphitic carbons (carbon nanotubes and reduced graphene oxide). The nanomaterials are dispersed in a matrix of polydimethyl-siloxane and spun onto a metal-coated plastic substrate. This method enables the production of self-powered energy-harvesting systems in a simple, low-cost, and large-scale manner, thus overcoming the limitations of previous nanogenerators. The resulting device is demonstrated on page 2999.

Tactile sensors with high spatial resolution are crucial to manufacture large scale flexible electronics, and low crosstalk sensor array combined with advanced data analysis is beneficial to improve detection accuracy. Here, we demonstrated the photo-reticulated strain localization films (prslPDMS) to prepare the ultralow crosstalk sensor array, which form a micro-cage structure to reduce the pixel deformation overflow by 90.3% compared to that of conventional flexible electronics. It is worth noting that prslPDMS acts as an adhesion layer and provide spacer for pressure sensing. Hence, the sensor achieves the sufficient pressure resolution to detect 1 g weight even in bending condition, and it could monitor human pulse under different states or analyze the grasping postures. Experiments show that the sensor array acquires clear pressure imaging and ultralow crosstalk (33.41 dB) without complicated data processing, indicating that it has a broad application prospect in precise tactile detection.

Traffic lights play vital roles in urban traffic management systems, providing clear directional guidance for vehicles and pedestrians while ensuring traffic safety. However, the vast quantity of traffic lights widely distributed in the transportation system aggravates energy consumption. Here, a self-powered traffic light system is proposed through wind energy harvesting based on a high-performance fur-brush dish triboelectric nanogenerator (FD-TENG). The FD-TENG harvests wind energy to power the traffic light system continuously without needing an external power supply. Natural rabbit furs are applied to dish structures, due to their outstanding characteristics of shallow wear, high performance, and resistance to humidity. Also, the grid pattern of the dish structure significantly impacts the TENG outputs. Additionally, the internal electric field and the influences of mechanical and structural parameters on the outputs are analyzed by finite element simulations. After optimization, the FD-TENG can achieve a peak power density of 3.275 W m

Abstract The pursuit of sustainable and self‐sufficient energy solutions has become critical for the advancement of marine Internet of Things (IoT) technologies. While triboelectric nanogenerators (TENGs) have shown great potential in harnessing high‐entropy, low‐frequency wave energy, their practical applications are hindered by low power output and issues related to frictional wear. Hence, this research presents a novel non‐contact bidirectional spinning oscillating float‐type triboelectric nanogenerator (OF‐TENG) for efficient wave energy harvesting. Utilizing a planetary gear and bidirectional rotation structural design, low‐frequency vertical wave energy with random and multi‐directional conditions can be converted into high‐frequency rotational energy. At a frequency of 0.5 Hz, the OF‐TENG achieves a peak output power of 93.48 mW, and an average output volumetric power density of 31.3 W m⁻ 3 . Furthermore, the non‐contact working mode ensures robust output stability, with no significant performance degradation observed after 5,680,000 working cycles. An intelligent self‐powered marine ranching system for automatic feeding and water quality monitoring is further developed based on the OF‐TENG. This work not only provides an effective solution for harvesting low‐frequency wave energy, but also promotes the development of smart marine IoT technologies and marine agriculture.

Investigating the piezotronic effect in p-type piezoelectric semiconductor is critical for developing a complete piezotronic theory and designing/fabricating novel piezotronic applications with more complex functionality. Using a low temperature solution method, we were able to produce ultralong (up to 60 μm in length) Sb doped p-type ZnO nanowires on both rigid and flexible substrates. For the p-type nanowire field effect transistor, the on/off ratio, threshold voltage, mobility, and carrier concentration of 0.2% Sb-doped sample are found to be 10(5), 2.1 V, 0.82 cm(2)·V(-1)·s(-1), and 2.6 × 10(17) cm(-3), respectively, and the corresponding values for 1% Sb doped samples are 10(4), 2.0 V, 1.24 cm(2)·V(-1)·s(-1), and 3.8 × 10(17) cm(-3). We further investigated the universality of piezotronic effect in the as-synthesized Sb-doped p-type ZnO NWs and reported for the first time strain-gated piezotronic transistors as well as piezopotential-driven mechanical energy harvesting based on solution-grown p-type ZnO NWs. The results presented here broaden the scope of piezotronics and extend the framework for its potential applications in electronics, optoelectronics, smart MEMS/NEMS, and human-machine interfacing.

Maintaining a high working frequency is critical one of technical solutions to the triboelectric nanogenerator (TENG) for improving its output power. Herein, we report a 3D-printed bearing-structural TENG (BS-TENG), which achieved a speed breakthrough of nearly 1500 rpm for the first time by 3D-printing diversified design whereby to enable even higher working frequency. Integrated BS-TENGs network can be utilized as both rotational energy harvester and self-powered high speed sensing system for vehicle temperature and speed real-time monitoring. It was vital that one unit delivers a peak power of 0.96 mW under an external load of 8 MΩ. Moreover, a capacitor of 1000 µF was charged by integrated energy harvester to achieve voltage of 4 V that just take nearly 80 s under rotational speed of 600 rpm. Furthermore, the results confirmed that the accuracy of the self-powered vehicle speed monitoring could more than 99% level under a wide range of 100 to 1500 rpm. This study not only presents a new approach for upgrading the working frequency of TENGs, but also provides new opportunities for TENGs in intelligent vehicle autonomous driving system.

Paper-based functional electronic devices endow a new era of applications in radio-frequency identification (RFID), sensors, transistors and microelectromechanical systems (MEMS). As an important component for building an all paper-based system that can work independently and sustainably, a paper-based power source is indispensable. In this study, we demonstrated a paper-based nanogenerator (pNG) that can convert tiny-scale mechanical energy into electricity. The pNG relies on an electrostatic effect, and the electrostatic charges on the paper were generated by the corona method. The instantaneous output power density of a single-layered pNG reached ∼90.6 μW cm−2 at a voltage of 110 V, and this instantaneously illuminated 70 LEDs. In addition, by sticking the pNG to a movable object, such as the page of a book, the power harvested from the mechanical action of turning the page can drive an LED, which presents its outstanding potential in building paper-based, self-powered systems and as active sensors.

Solid-state in-plane microsupercapacitor is realized on the woven textile substrate for the first time with mask-aided electroless coating of Ni and hydrothermal reduction of graphene oxides. High capacitive performances, excellent flexibility, and versatile capability in fashionable/comfortable designs are obtained for the application in smart textiles or wearable electronics. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.