Wang Lu, assistant professor of School of Instrument Science and Technology, Xi 'an Jiaotong University, Deputy Secretary of Party Branch of Institute of Intelligent Sensor and System, winner of national "Postdoctoral Innovative Talent Program", Class A Excellent Youth Talent Program of Xi' an Jiaotong University, A member and administrator of Micro and Nano Manufacturing Technology Branch of Chinese Mechanical Engineering Society. He graduated from the School of Mechanical Engineering of Xi 'an Jiaotong University with a bachelor's degree and doctorate degree under Academician Jiang Zhuangde. During this period, he studied in the National University of Singapore for one year with sponsorship by CSC. His main research interests are energy harvesting and wireless sensing self-supply technology. He is committed to the theoretical analysis, device design and manufacturing, power management of piezoelectric, electromagnetic, triboelectric and other energy harvesting, and the application research of self-powered wireless sensing system.

The applicant has presided over 7 projects, including the NSFC Youth Foundation, National Key R&D Program, Postdoctoral Innovation Talent Support Program, State Key Laboratory Project, State Grid Technology Project, and Shaanxi Provincial Youth Fund, with a total funding of 4.78 million yuan. Published 32 SCI and EI papers in international renowned journals such as Nano Energy (IF=19.069), Applied Energy (IF=11.2), ACS Applied Materials & Interfaces (IF=8.3). Among them, 17 papers with first or corresponding author SCI (1 with high ESI), 21 invention patents (8 have been authorized), Participated 15 international and domestic academic conferences (11 oral reports). He has won the sixth batch of National Postdoctoral Innovative Talents Support Program, Shaanxi Provincial Outstanding Doctoral Dissertation, 2023 MINE Outstanding Young Scientist Award, and top 10 Medical Talents of Xi'an Jiaotong University in 2023.

In the era of the Internet of Things, wireless sensors are widely deployed, battery life is limited, and energy harvesting and self-powered sensing technology are effective and sustainable solutions. The applicant has been engaged in energy harvesting and wireless sensing self-supply technology for a long time, and the main research achievements and academic contributions are as follows:

The piezoelectric vibration, coil magnetic field and cylinder electric field energy harvesting theory and circuit model are established. The high performance and high reliable piezoelectric vibration energy harvester (PVEH) structure design and preparation method, the high current magnetic field discharge protection method and high voltage electric field energy harvesting discharge method are putted forward. The multi-frequency broadband PVEH device, wide current magnetic field energy device and high voltage electric field energy device are developed. The magnetic-electric-vibration energy harvesting problem in grid transmission and transformation monitoring scene are solved.

In the monitoring scenario of power transmission and transformation, the vibration, magnetic field and electric field generated by the operation of the power grid are more stable than the environmental energy such as photovoltaic and wind power. It is necessary to develop high power density PVEH devices to improve the practicability and versatility, and meet the industrial applications as soon as possible. The applicant studied the dynamic theory of PVEH electromechanical coupling, and proposed a two-dimensional equivalent finite element modeling method for the piezoelectric cantilever beam structure and material parameters. Reducing the simulation time greatly reduces the simulation error from 28% to 1.2%. He optimize the design method of PVEH massive structure, analyze the relationship between the bond length and resonance frequency and open circuit voltage, and propose the L-shaped massive low-frequency PVEH structure. Compared with the traditional rectangular mass block PVEH, the mass block length can be increased while the sufficient piezoelectric bond length is maintained, the resonance is reduced and the piezo power output is improved, and the contradiction between the mass block and the piezoelectric layer in the finite volume is solved.

To realize PVEH fixed frequency and extension frequency resonance, he studied the load impedance, additional quality, glue filling, axial and transverse magnetic frequency modulation method, compared the assembly method of piezoelectric double chip, put forward the packaging method of aluminum alloy frame glue insert piezoelectric cantilever, compared with the laminating bonding process, improve the resonance quality factor and long-term stability. The nonlinear vibration extension mechanism such as collision, magnetic coupling and array is studied, and the PVEH double-point limit amplitude design method is proposed to convert the collision force into bending moment under large amplitude, optimize the uniform distribution of piezoelectric layer stress along the beam length. The vibration acceleration range of PVEH is improved from 0.1g to 4g, and the vibration energy harvesting working frequency band is widened.

To improve the efficiency of piezoelectric energy extraction circuit, the modeling and design method of synchronous switching interface circuit are studied, and the adaptive mechanical rectification optimized synchronous charge extraction (M-OSECE) circuit is proposed, and the generating power is 60% more than the traditional standard energy harvesting circuit (SEH). For energy harvesting from the power supply system storage cannot adaptive matching problem, he puts forward the whole system circuit modeling simulation and parameter identification method, optimizes the wide under voltage lock design increases the instantaneous discharge energy, solves the peak power consumption of the node startup system power problem, mastered the PVEH driven WSN power supply system of basic theory and the whole system design method.

Accordingly, 100 / 200 / 300Hz multi-frequency point vibration energy harvesting device for applicable power grid transformer and 3-150Hz wide band vibration energy harvesting device for applicable power grid overhead line are designed. The relevant results and prototypes were used for the acceptance of the State Grid project, and were tested and verified by a third party. The self-supply application verification of the wireless sensor for multi-frequency point vibration energy acquisition was carried out on the site of the 500kV transformer of Guangxi Power Grid.

Relying on the national key RESEARCH and development plan and with the support of China Southern Power Grid, the research on magnetic-electric-vibration multi-source efficient self-energy technology has been carried out. For the magnetic field energy taking of primary current of transmission line, the paper studied the model. The combination and switching of weak starting circuit and strong discharge energy harvesting circuit are proposed. A wide range magnetic field energy harvesting module can obtain 1A start and withstand 100 kA impact, which can output 20W energy harvesting power at the 100A power frequency magnetic field. In view of the high voltage electric field, a low-cost, self-driving and adjustable range of high voltage undervoltage lock discharge circuit is proposed, and the output impedance is reduced through the circuit topology of series transfer and parallel, and the energy harvesting power is increased by more than 5 mW @ 110 kV. The relevant results and prototypes are used for the acceptance of national key R & D plan projects, and are verified by a third party.

(2)Combined with the hybrid vibration energy harvesting and sensing mechanism of piezoelectric, electromagnetic and triboelectricity, an intelligent wireless monitoring system with self-powering self-sensing and self-awakening is proposed, which solves the problem of sustainable wireless monitoring of traffic, power grid and wearable equipment.

Traditional hybrid energy harvesting research only as a power generation function, the applicant explored the hybrid vibration power generation and sensing mechanism, with double T simple beam piezoelectric vibration energy harvester (PVEH) as the basis, as the power supply unit, cleverly designed the contact separation friction nanomogenerator (TENG) to harvest collision energy, and as a vibration acceleration sensing unit, RF, sustainable wireless vibration sensing under vibration excitation, structure both axial force frequency modulation and collision extension function, experiment verified the feasibility of the train sustainable self-supply wireless vibration monitoring application. The results was published in Nano Energy, 2021,80:105555, (IF=19.069), ESI cited 96 times.

Redundant data and large amounts of power consumption limit the application of wearable flexible sensors in sustainable wireless sensing. This study presents a bridge-structured flexible hybrid nanogenerator for self-powered wearable sensors. When obtaining energy from finger bending movement, TENG contact separation mode can trigger the wireless sensor node and harvest the bending angle sensor signal of piezoelectric generator for self-powered wireless human-computer interaction. The work was published in Nano Energy, 2023,112:108504. (IF=19.069) and was cited 34 times.

To realize self-powered intelligent vibration sensing, a three-function hybrid generator is designed to integrate electromagnetic-piezoelectric-triboelectric units into an arched vibration energy harvesting structure. The electromagnetic unit is used for power supply, and two piezoelectric units serve as accelerometers for amplitude and frequency sensing, with broad band decoupling function; the triboelectric unit is used to trigger self-wake wireless sensing nodes, which reduces the power consumption by 94.2%. The application of wireless vibration sensing is validated on automotive engines. The results was published in Applied Energy, 355:122207 (2024). (IF=11.2), was cited 11 times.