Wearable nanogenerators are of vital importance to portable energy-harvesting and personal electronics. Here we report a method to synthesize a lead zirconate titanate textile in which nanowires are parallel with each other and a procedure to make it into flexible and wearable nanogenerators. The nanogenerator can generate 6 V output voltage and 45 nA output current, which are large enough to power a liquid crystal display and a UV sensor.

Due to the large surface area‐to‐volume ratio and high quality crystal structure, single nanowire (NW)‐based UV sensors exhibit very high on/off ratios between photoresponse current and dark current. Practical applications require a large‐scale and low‐cost integration, compatibility to flexible electronics, as well as reasonably high photoresponse current that can be detected without high‐precision measurement systems. In this paper, NW‐based UV sensors were fabricated in large‐scale by integrating multiple NWs connected in parallel via the contact printing method. Linear scaling of the photoresponse current with the number of NWs is demonstrated. Integrated ZnO NW UV sensors were fabricated on rigid glass and flexible polyester (PET) substrates at the macroscopic scale. The flexible and rigid sensors performed comparably, exhibiting on/off current ratios approximately three orders of magnitude higher than sensors made from polycrystalline ZnO thin films. Under UV irradiance of 4.5 mW cm−2 and 3 V bias, photoresponse currents and on/off current ratios for the rigid and flexible UV sensors reached 12.22 mA and 82 000, and 14.1 mA and 120 000, respectively. This result suggests that lateral integration of semiconductor NWs is an effective approach to large‐scale fabrication of flexible NW sensors that inherit the merits of single‐NW‐based systems with unaffected performance compared to using rigid substrate.

On the basis of a vertically aligned ultralong Pb(Zr 0.52 Ti 0.48 )O 3 (PZT) nanowire array fabricated using electrospinning nanofibers, we developed a new type of integrated nanogenerator (NG) with ultrahigh output voltage of 209 V and current density of 23.5 μA/cm 2 , which are 3.6 times and 2.9 times of the previous record values, respectively. The output electricity can be directly used to stimulate the frog's sciatic nerve and to induce a contraction of a frog's gastrocnemius. The NG can instantaneously power a commercial light-emitting diode (LED) without the energy storage process. KEYWORDS: Nanogenerator, high output, energy harvesting, PZT nanowires, electrospinning H arvesting clean and renewable energy from the environment is an effective method to response the current energy crisis and power wide distributed nano/microdevices. As a novel energy collector, nanogenerator (NG) exhibits a number of features not shared by the traditional generators, that is, the ones based on ocean tide, river falls, and wind, etc. NG fabricated with piezoelectric nanomaterials can convert tiny and irregular environmental mechanical energy to electricity from sources such as air flowing, heart beating, and so on, which are more popular in our living environment compared to the energy source used for traditional generators as mentioned above.1 Moreover, due to its small size the NG can be effectively integrated with the nano/microscale functional devices to form a self-powered system, which has potential applications in the internet of things, national security, biomedical, and industry areas. In order to improve its output, many attempts have been made ranging from altering piezoelectric materials, that is, ZnO, 14 and so on. Among these systems, many of them need an energy storage unit to make them work properly. This energy storage circuit adds much complexity to the self-powered system and hinders its capacity to work in different tough environments. Here, we report a simple approach of fabricating vertically ultralong Pb(Zr 0.52 Ti 0.48 )O 3 (PZT) nanowire arrays from electrospinning fibers to make a high output NG. Benefiting from the ultralong length of vertical nanowires, the fabricated NG has a maximum output peak voltage of 209 V, which is much higher than the past record of 58 V.2 Also, the NG can output a maximum peak current of 53 μA and current density of 23.5 μA/cm 2 , which is 2.9 times of the recent highest value of 8.13 μA/cm 2 . 15 The output power of our NG can be directly used to stimulate the frog's sciatic nerve and induce a contraction of that frog's gastrocnemius. Moreover, the NG can power a commercial light-emitting diode (LED) instantly without energy storage, which is a considerable progress for the development of selfpowered devices.Previous studies have shown that high piezoelectric coefficient of the fabricating material and integrated parallel and serial connection designs are two major factors to effectively increase NG's output. So, we use PZT, which possesses the highest piezo...

A cloth-base wearable triboelectric nanogenerator made of nylon and Dacron fabric was fabricated for harvesting body motion energy. Through the friction between forearm and human body, the generator can turn the mechanical energy of an arm swing into electric energy and power an electroluminescent tubelike lamp easily. The maximum output current and voltage of the generator reach up to 0.2 mA and 2 kV. Furthermore, this generator can be easily folded, kneaded, and cleaned like a common garment.

In this paper, a new kind of 2D piezotronic transistor (PT) with the highest sensitivity till date has been designed and demonstrated, and the 2DPT array with ultrahigh spatial resolution has been developed through assembling ZnO nanoplatelets into ordered nanoplatelet array. As active sensors by directly converting applied mechanical actuations into electrical control signals without applying gate voltage, the ZnO 2DPT array has a great advantage as a fundamental component of piezotronics. The 2DPT array paves the way for a large-scale and integrated production of two terminal vertical transistors, which will contribute to its application in many fields such as human-machine interfacing, smart sensor, and processor systems.

Lead-free BZT-BCT (0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3) nanowires with a high piezoelectric coefficient are synthesized and nanogenerators (NGs) composed of them are successfully developed. The studied in vitro and in vivo biocompatibility of the NGs shows great potential for their application as in vivo power sources.

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A microfiber‐nanowire hybrid structure is the fundamental component for a wearable piezoelectric nanogenerator (PENG) for harvesting body motion energy. Here, a novel approach combining surface coating and plasma etching techniques is reported to enhance the mechanical reliability of Kevlar microfiber‐ZnO nanowires (NWs) hybrid structure that is used for PENG. After treatment, the hybrid structure has dramatically improved high flexibility, robustness, and durability. On the basis of the coupled piezoelectric and semiconducting properties of ZnO, the processed Kevlar fibers covered with ZnO NWs are utilized to fabricate a 2D nanogenerator (2DNG). The open‐circuit voltage and short‐circuit current of the 2DNG are 1.8 mV and 4.8 pA, respectively. Furthermore, the 2DNG is successfully employed to quantitatively detect UV intensity from 0.2 to 1 mW cm−2 as a self‐powered system.