Publications

High-quality ultra-long alloyed CdS(x)Se(1)(-)(x) (0 < or = x < or = 1) whiskers were obtained by a simple thermal evaporation route. The near band-edge emission in these whiskers can be effectively guided at the sub-millimeter scale under continuous-wave laser excitation. As good optical waveguide cavities, the whiskers exhibit stimulated emissions under pulsed light excitation at room temperature for all compositions 0 < or = x < or = 1. The spectral positions of the sharp emission lines of the whiskers were tuned by their compositions, covering the spectral range from green to red.

Abstract The triboelectric nanogenerator (TENG) holds significant potential for applications in energy harvesting and environment monitoring. However, a notable challenge lies in developing a combined system capable of efficiently harvesting energy and providing real‐time self‐powered sensing. Here, a combined wind energy harvesting and speed sensing (EHSS) system is constructed based on a noncontact electricity‐induced constant‐voltage TENG (EICV‐TENG) that achieves constant output by coupling two different phases and incorporates a parasitic sensing module in a single phase. Through the optimization of system integration, the EICV‐TENG achieves a current density of 28.7 mA m −2 and an average power density of 0.26 W m −2 Hz −1 . With an optimal power management, the energy output efficiency of the EICV‐TENG reaches up to 96%. And EICV‐TENG can stably power 32 commercial hygrothermographs connected in parallel with the PMC at a wind speed of 7 m s −1 . In addition, the EHSS system demonstrates excellent real‐time sensing performance based on the correlation between the peak number of pulse output in a single phase and wind speeds. This work contributes to the advancement of TENG technology for a combined energy harvesting and self‐powered sensing system in the context of the Internet of Things (IoTs).

Abstract With the rapid development of transportation technology, people's lives are becoming more and more convenient, but the popularity of high speed transportation also increases the probability of emergencies. Therefore, it is necessary to conduct real‐time and accurate monitoring on transportation conditions to reduce the occurrence of emergencies. For possibly emergencies in other circumstances (e.g., meteorological disasters, geological disasters, and maritime disasters), emergency management is also critical to ensure the security of people and property. Prediction and early‐warning can help to detect abnormal situations and take measures, prior to potential risks. The basis of real‐time and effective transportation monitoring and emergency management requires a continuous and stable power supply for randomly distributed sensors and actuators. Triboelectric nanogenerators (TENGs) have been extensively investigated in different transportation circumstances to harvest the surrounding energy and drive distributed sensors for self‐powered wireless monitoring. This article surveys the research progress in TENGs in road transportation, bridge transportation, railway transportation, and maritime transportation, and related surrounding emergency management. Representative applications and the main achievements are summarized for these different application scenarios. A perspective on TENG research is given, and the remaining challenges facing TENGs in transportation and emergency management are discussed, along with potential solutions.

One-dimensional semiconductors with wurtzite structure, such as GaN, ZnO and CdS nano/microwires, exhibit superior semiconductor, piezoelectric and mechanical properties, making them excellent candidates for novel electronic, opto-electronic devices and integrated systems. More importantly, the coupling between piezoelectric polarization and semiconductor properties (including electric transport and photoexcitation) gives rise to unique and unprecedented physical characteristics and has led to emerging fields of piezotronics and piezo-phototronics. On the basis of the extensive studies in c-axis semiconductor nano/microwires, piezotronics and piezo-phototronics based on a-axis nano/microwires have further been explored and demonstrated recently. We review both the fundamental progresses and developed applications of piezotronics and piezo-phototronics based on a-axis nano/microwires, which further improve the theoretical framework and expand the practical applications of piezotronics and piezo-phototronics in functional nanodevices and nanosystems.

A highly-efficient, lightweight, flexible, piezoelectric lead zirconate titanate (PZT) thin-film nanogenerator is demonstrated by employing the laser lift-off transfer technique and a lateral electrode structure. As reported by K. J. Lee and co-workers on page 2514, this large-area PZT thin-film nanogenerator can convert to the highest output performance from a slight mechanical deformation and provides the feasibility of fully flexible self-powered electronics.

Next Generation EO/IR focal plane arrays using nanostructure materials are being developed for a variety of Defense Applications including Unattended Ground Sensor Applications. These include ZnO nanowires that have demonstrated large signal to noise ratio as a wide band gap nanostructure material in the UV band. Similarly, the work is under way using Carbon Nanotubes (CNT) for a high speed detector and focal plane array as bolometer for IR bands of interest, which can be implemented for the unattended ground sensor applications. In this paper, we will discuss the sensor design and model predicting performance of an EO/IR focal plane array that can cover the UV to IR bands of interest. The model can provide a robust means for comparing performance of the EO/IR FPA's and Sensors that can operate in the UV, Visible-NIR (0.4-1.8μ), SWIR (2.0-2.5μ), MWIR (3-5μ), and LWIR bands (8-14μ). This model can be used as a tool for predicting performance of nanostructure arrays under development. We will also discuss our results on growth and characterization of ZnO nanowires and CNT's for the next generation sensor applications.

Recently, some scholars suggested that it is important to keep a stablehemodynamic state and prevent the stress responses in geriatric patients undergoing total hip replacement (THR). We conducted this randomized prospective study to observe anesthetic potency of unilateral spinal anesthesia and stress response to it in geriatric patients during THR. We compared the effect of unilateral spinal and bilateral spinal on inhibition of stress response through measuring Norepinephrine (NE), epinephrine (E) and cortisol (CORT). Plasma concentrations of NE, E and CORT were determined in blood samples using ELISA (enzyme-linked immunosorbent assays) at three time points: To (prior to anesthesia) T1 (at the time point of skin closure), T2 (twenty-four hours after the operation). Sixty patients were randomly divided into two groups: group A (unilateral spinal anesthesia) and group B (conventional bilateral spinal anesthesia). 7.5tymg of hypobaric bupivacaine were injected into subarachnoid cavity at group A and 12mg hypobaric bupivacaine were given at group B. The onset time of sensory and motor block, loss of pinprick sensation, degree of motor block, regression of sensory and motor blocks and hemodynamic changes were also recorded. These data were used to evaluate anesthetic potency of spinal anesthesia. The results of this experiment show that unilateral spinal anesthesia can provide restriction of sensory and motor block, minimize the incidence of hypotension and prevent the stress responses undergoing THR. It is optimal anesthesia procedure for geriatric patients by rapid subarachnoid injection of small doses of bupivacaine.

A harmonic-resonator-based triboelectric nanogenerator (TENG) is presented as a sustainable power source and an active vibration sensor. It can effectively respond to vibration frequencies ranging from 2 to 200 Hz with a considerably wide working bandwidth of 13.4 Hz. This work not only presents a new principle in the field of vibration energy harvesting but also greatly expands the applicability of TENGs. 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.

The operation cost of an intelligent high-speed train system is greatly increased by the enormous energy demand of large-scale signal and sensor networks. However, the wind energy generated by high-speed trains is completely neglected. Herein, a wind-energy-harvesting device, which is based on an elastic rotation triboelectric nanogenerator (ER-TENG), is fabricated to harvest the wind energy generated by high-speed moving trains and power the relevant signal and sensing devices. Due to the significant decrease in friction force resulting from reasonable material selection and elastic structure design, the energy-harvesting efficiency of an ER-TENG is doubled and the durability is increased by 4 times compared to the same characteristics of a conventional rotation sliding triboelectric nanogenerator (RS-TENG). Our findings not only provide an in situ energy-harvesting pattern for an intelligent high-speed rail system by recovering the otherwise wasted wind energy generated by high-speed trains but also offer a potential strategy for large-scale wind energy harvesting by TENGs.

Triboelectric nanogenerator (TENG) has been proven to be efficient for harvesting water wave energy, which is one of the most promising renewable energy sources. In this work, a TENG with a silicone rubber/carbon black composite electrode was designed for converting the water wave energy into electricity. The silicone-based electrode with a soft texture provides a better contact with the dielectric film. Furthermore, a spring structure is introduced to transform low-frequency water wave motions into high-frequency vibrations. They together improve the output performance and efficiency of TENG. The output performances of TENGs are further enhanced by optimizing the triboelectric material pair and tribo-surface area. A spring-assisted TENG device with the segmented silicone rubber-based electrode structure was sealed into a waterproof box, which delivers a maximum power density of 2.40 W m–3, as triggered by the water waves. The present work provides a new strategy for fabricating high-performance TENG devices by coupling flexible electrodes and spring structure for harvesting water wave energy.