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In-plane micro-supercapacitors (MSCs) possess the capabilities of easy integration with planar circuits and feasible flexibility when they are used in flexible and wearable electronics. However, their unsatisfactory energy density limits their wide application. The Zn-ion hybrid supercapacitor is an ideal candidate as it assimilates the high energy-density of the zinc metal anode and high power-density of the pseudocapacitive material cathode. In view of the fact that multiple-metal MXenes could exhibit great potential compared to the single-metal MXenes in energy storage capability, here, Zn//V3CrC3Tx supercapacitors are fabricated. It is found that the partial replacement of Cr atoms for V atoms in V4C3Tx triggers an expansion of layer spacing of the MXene, the adsorption of Zn ions increases, and ion diffusion is promoted, which dramatically improve the capacitance, discharging potential, and cycle stability. Furthermore, in-plane Zn//V3CrC3Tx MSCs on paper demonstrate outstanding electrochemical properties and mechanical flexibility with an ultra-high area energy-density of 51.12 μW h cm−2, long cycle life of 20 000 cycles (84.5% capacitance retention), and outstanding bendability of 10 000 cycles (80.2% capacitance retention). The areal energy density and flexibility outperform most of the reported in-plane flexible MSCs. Owing to the emerging materials design and consummate flexible nature of the scheme, it can inject fresh strength into the development of flexible electronics. [ABSTRACT FROM AUTHOR]

Wind is one of the most important sources of green energy, but the current technology for harvesting wind energy is only effective when the wind speed is beyond 3.5–4.0 m s−1. This is mainly due to the limitation that the electromagnetic generator works best at high frequency. This means that light breezes cannot reach the wind velocity threshold of current wind turbines. Here, a high‐performance triboelectric nanogenerator (TENG) for efficiently harvesting energy from an ambient gentle wind, especially for speeds below 3 m s−1 is reported, by taking advantage of the relative high efficiency of TENGs at low‐frequency. Attributed to the multiplied‐frequency vibration of ultra‐stretchable and perforated electrodes, an average output of 20 mW m−3 can be achieved with inlet wind speed of 0.7 m s−1, while an average energy conversion efficiency of 7.8% at wind speed of 2.5 m s−1 is reached. A self‐charging power package is developed and the applicability of the TENG in various light breezes is demonstrated. This work demonstrates the advantages of TENG technology for breeze energy exploitation and proposes an effective supplementary approach for current employed wind turbines and micro energy structure. [ABSTRACT FROM AUTHOR]

The sensor devices based on triboelectric nanogenerator (TENG) have been proved to have both high sensitivity and good self‐powered capability. Inspired by the cockroach antennae, a bionic‐antennae‐array (BAA) sensor based on the working principle of TENG is proposed for identifying the noncontact motions and a data processing module is specially designed for outputting electrostatic signal to the microcontroller unit (MCU). Based on the amplifying effect of antennae array, the detected maximum distance by this BAA sensor can reach 180 mm with a displacement resolution of 1 mm and maximum sensitivity of about 5.6 V mm−1 (at approaching angle of 90°). The influences of several critical factors, such as approaching angle, motion velocity, and target materials, to the performance of this BAA sensor are systematically studied. Meanwhile, the BAA sensor is integrated with proximity switch, intelligent robot, and mobile vehicles for realizing the function of motion alarming and obstacle detecting. The high sensitivity and the easy fabrication process of this TENG‐based BAA sensor show great application potentials in the field of industrial robotics, human–machine interactions, artificial intelligence, etc. [ABSTRACT FROM AUTHOR]

Here, a smart microfluidic system that can realize both long distance transport of micro‐/nanodroplets and precise patterning of microfluidics is designed based on triboelectric nanogenerator (TENG) and a photocontrollable adhesion surface (PCAS). The high output voltage from TENG can eject a microdroplet to a maximum distance of 640 mm (a maximum distance/diameter ratio of 300), while TENG can also manipulate the microdroplet under a thick dielectric layer (2 mm). Meanwhile, water adhesion as well as contact angle of the PCAS changes significantly with a short period of UV treatment and thus it can help to capture the moving microfluidics at the designated position. Moreover, microfluidic patterning with a variety of patterns and arrays on this PCAS can be obtained by using UV imprinting and the combination of TENG and PCAS can achieve an effective self‐powered microfluidic patterning system. Finally, a tunable gripper probe for 3D transport of microdroplets is demonstrated as another application of TENG and PCAS. These smart microfluidic systems based on TENG and PCAS have excellent applicability for many fields, such as drug/cell delivery, controllable chemical reaction for liquid testing, and production of microdroplets. A smart microfluidic system that can realize long distance transport of droplets and precise microfluidic patterning is designed based on triboelectric nanogenerator (TENG) and photocontrollable adhesion surface (PCAS). The high voltage from TENG can eject a microdroplet to a maximum distance of 640 mm. With UV treatment, the PCAS can capture the moving microfluidics at the designated position. [ABSTRACT FROM AUTHOR]

Piezoelectric organic-inorganic lead halide perovskites have recently attracted much attention in the field of optoelectronic devices. However, their piezoelectric properties as a possible way to modulate device performances have rarely been reported. Here, we study experimentally a photodetector based on CH 3 NH 3 PbI 3 (MAPbI 3 ) single crystals, whose performance is effectively modulated via an emerging effect-the piezo-phototronic effect, which is to use the piezoelectric polarization charges to tune the optoelectronic processes at the interface. A piezoelectric coefficient of 10.81 pm/V of the CH 3 NH 3 PbI 3 single crystal is obtained. Under 680 nm laser illumination with a power density of 3.641 mW/cm 2 and at an external bias of 2 V, compared to the case without straining, the light current of the photodetector is enhanced by ∼120% when a 43.48 kPa compressive pressure is applied. The response speed of the photocurrent is 3 and 2 times faster than the cases without applying pressure for the light-on and light-off states, respectively. This work proves that the performance of the photodetector based on MAPbI 3 single crystals can be effectively enhanced by the piezo-phototronic effect, providing a good method for optimizing the performance of future perovskite-based optoelectronic devices.