Publications

Triboelectric nanogenerators (TENGs) have been widely used in energy harvesting from low-frequency, irregular motions due to their unique characteristics and excellent electromechanical conversion efficiency. Harvesting ocean energy to build a marine Internet of Things (MIoTs) has become an important research field for TENGs. However, the output power density of TENGs must be further enhanced for promoting their practical applications, by effective means such as the coupling of TENGs and electromagnetic generators (EMGs). Herein, we report a triboelectric-electromagnetic hybrid nanogenerator (TEH-NG) for self-powered ocean buoy to harvest water wave energy efficiently for the first time. The buoy consists of a self-engineered wave energy converter for converting wave energy into simple turbomachinery energy through the pressure difference created by the relative motion, and a TEH-NG for converting the turbomachinery energy into electrical energy. The TENG delivers an average output power of 3.40 mW (with power density of 141.7 W m−3), and the EMG achieves an average power of 0.04 W (with power density of 400.0 W m−3). The excellent performance of the TEH-NG makes it a potential candidate for constructing the MIoTs to achieve distributed marine environmental monitoring networks.

A hybridized self-powered textile for simultaneously collecting solar energy and random body motion energy was demonstrated.

The development of industry and of the Internet of Things (IoTs) have brought energy issues and huge challenges to the environment. The emergence of triboelectric nanogenerators (TENGs) has attracted wide attention due to their advantages, such as self-powering, lightweight, and facile fabrication. Similarly to paper and other fiber-based materials, which are biocompatible, biodegradable, environmentally friendly, and are everywhere in daily life, paper-based TENGs (P-TENGs) have shown great potential for various energy harvesting and interactive applications. Here, a detailed summary of P-TENGs with two-dimensional patterns and three-dimensional structures is reported. P-TENGs have the potential to be used in many practical applications, including self-powered sensing devices, human–machine interaction, electrochemistry, and highly efficient energy harvesting devices. This leads to a simple yet effective way for the next generation of energy devices and paper electronics.

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 CH3NH3PbI3(MAPbI3) 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 CH3NH3PbI3 single crystal is obtained. Under 680 nm laser illumination with a power density of 3.641 mW/cm2 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 MAPbI3 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.

Conventional electronic combination lockers are usually constructed with an active password input module, which requires the necessary electrical connections. In this work, a new passive smart electronic password locker based on photoelectric signal conversion is reported. When a ZnS-based mechanoluminescent material is subjected to an external force, the mechanical stimulus is converted into light energy. According to this light-emitting property, we developed an optical signal unit as the password input module of the password locker. Benefiting from the mechanoluminescence properties of the ZnS:Cu and randomly distributable visible light sensor, the electronic password locker key has good concealment and randomness. In addition, the surface coating treatment reduces the risk of fingerprint leakage, thus further improving the security performance of the password locker. This work broadens the application path for ZnS-based mechanoluminescence materials, which provides a novel perspective for practical applications such as a smart home.

A pressure-sensitive matrix (PSM) with a full dynamic-range is shown by Caofeng Pan, Zhong Lin Wang, and co-workers in article number 1605817 to be able to accurately detect and spatially map a pressure profile. A 100 × 100 large-scale PSM gives both electrical and optical signals by itself without application an external power. The device represents a major step toward digital imaging, and the visible display of the pressure distribution covers a large dynamic range.

Equipping wearable electronics with special functions will endow them with more additional values and more comprehensive practical performance. Here, we report an ultraviolet (UV)-protective, self-cleaning, antibacterial, and self-powered all-nanofiber-based triboelectric nanogenerator (TENG) for mechanical energy harvesting and self-powered sensing, which is fabricated with Ag nanowires (NWs)/TPU nanofibers and the TiO2@PAN networks through a facile electrospinning method. Due to the added TiO2 nanoparticles (NPs), the TENG presents excellent UV-protective performance, including the ultraviolet protection factor (UPF) of ∼204, the transmittance of UVA (TUVA) of ∼0.0574%, and the transmittance of UVB (TUVB) ∼0.107%. Furthermore, under solar lighting for 25 min, most surface contamination can be degraded, and the decreased power output would be recovered. Owing to the coupled effects of TiO2 NPs and Ag NWs, the TENG shows excellent antibacterial activity against Staphylococcus aureus. Due to the micro-to-nano hierarchical porous structure, the all-nanofiber-based TENG can serve as self-powered pedometers for detecting and tracking human motion behaviors. As a multifunctional self-powered device, the TENG prompts various applications in the fields of micro/nanopower sources, human movement monitoring, and human-machine interfaces, potentially providing an alternative energy solution and a multifunctional interactive platform for the next-generation wearable electronics.

Objective To analyze the clinical characteristics and screen pathogens and prognosis of anti-N-methyl-D-aspartate receptor(NMDAR) encephalitis in children and so as to improve the diagnosis and treatment of anti-NMDAR encephalitis in children. Methods A retrospective and follow-up analysis of 38 cases of pediatric anti-NMDAR encephalitis was performed, who were admitted to the West China Second University Hospital, Sichuan University from May 2012 to June 2016, and their clinical features, associated pathogen screening, treatment and prognosis were reviewed. Results Those 38 cases included 14 males and 24 females.The age ranged from 1 year and 10 months to 17 years and 6 months.The most common symptoms were psychiatric symptoms (33 cases), and dyskinesias and movement disorders (33 cases), speech disturbances (31 cases). Twenty-four cases (63.2%) received positive pathogenic screening and only one case had right ovarian mature cystic teratoma.Among them, 11 cases had positive mycoplasma pneumonia immunoglobulin M(IgM) antibodies, 10 cases had positive virus screening, and 1 case had toxoplasma gondii IgM antibodies positive, and 2 cases had mix infection.Symptoms of one case were relieved after anti-toxoplasma treatment without immunosuppression treatment, and another case had partial symptom relief after mycoplasma pneumonia treatment.Thirty-seven cases received immunosuppressant therapy(4 cases were treated with glucocorticoid, 12 cases were treated with glucocorticoid combined with immune globulin, 2 cases were treated with glucocorticoid combined with plasma exchange, still 19 cases were treated with glucocorticoid combined with immune globulin and plasma exchange). After follow-up for median 12 months, 3 cases relapsed, 29 cases were fully recovered, 5 cases had mild language impairment, 2 cases had mild memory impairment, and 2 cases had involuntary movement. Conclusions The most common symptoms of the patients were psychiatric symptoms, dyskinesias and movement disorders, and speech disturbances.Children with anti-NMDAR encephalitis had a low incidence of tumors, while various pathogen infections including mycoplasma pneumonia, virus and toxoplasma gondii, which may trigger abnormal immune response of anti-NMDAR encephalitis.Pathogen screening needs to be done for pediatric anti-NMDAR encephalitis and anti-pathogenic treatment may be helpful for disease remission. Key words: Anti-N-methyl-D-aspartate receptor encephalitis; Pathogen; Child

Using a metal−semiconductor−metal back-to-back Schottky contacted ZnO microwire device, we have demonstrated the piezoelectric effect on the output of a photocell. An externally applied strain produces a piezopotential in the microwire, which tunes the effective height of the Schottky barrier (SB) at the local contact, consequently changing the transport characteristics of the device. An equivalent circuit model together with the thermionic emission theory has explained the four kinds of relationships observed between the photocurrent and the applied strain. Our study shows the possibility of maximizing the output of a photocell by controlling strain in the device.

Growth of aligned and uniform α-Fe2O3 nanowire (NW) arrays has been achieved by a vapor–solid process. The experimental conditions, such as type of substrate, local growth and geometrical environment, gas-flow rate, and growth temperature, under which the high density α-Fe2O3 NW arrays can be grown by a vapor–solid route via the tip-growth mechanism have been systematically investigated. The density of the α-Fe2O3 NWs can be enhanced by increasing the concentration of Ni atoms inside the alloy substrate. The synthesized temperature can be as low as 400 °C. Fe3O4 NWs can be produced by converting α-Fe2O3 NWs in a reducing atmosphere at 450 °C. The transformation of phase and structure have been observed by in situ transmission electron microscopy. The magnetic and field-emission properties of the NWs indicate their potential applications in nanodevices.