Prof. Kai Wang
Prof. Kai Wang

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Prof. Kai Wang(Link)

Qingdao University/College of Electrical Engineering


Brief introduction:


Graduate from Dalian University of Technology in College of Electrical Engineering,The applicant is employed as a member of the Component Professional Committee of the Chinese Power Supply Society and a member of the Shandong Electronic Ceramics Committee, a distinguished professor of the school, a dean of the electrical engineering department, a core member of the National and Local Joint Engineering Research Center for Intelligent Power Integration Technology of Electric Vehicles (Qingdao), Shandong Deputy Director of Provincial New Energy Automobile Electrical and Electronic Engineering Technology Research Center, Deputy Director of Qingdao Intelligent Electrical Appliances and Intelligent System Engineering Laboratory, and master's supervisor. The first author of the applicant published an academic monograph-supercapacitors and their applications in energy storage systems (Machinery Industry Press, 2019, CIP (2019) No. 276376). Outstanding reviewer of the Proceedings of the Chinese Society of Electrical Engineering and Applied Energy in 2019. The applicant has published more than 20 SCI research papers, which have been cited more than 900 times, and 6 ESI highly cited papers.


Speech Title: Application of Piezoelectric Nanogenerator in 3D Dynamic Sensing and Human-computer Interaction


Abstract: 

In recent years, with the development of intelligent processes, more and more researches have been conducted on flexible wearable devices and sensing devices. However, the signal acquisition and processing in a flexible environment have the disadvantages of low signal acquisition resolution, poor environmental adaptability, and narrow information flow. In order to improve the flexibility and performance of the sensing system, a self-powered piezoelectric nanogenerator was used to perform attitude tracking in high-resolution array signal sensing and human-machine interaction, and the interference mechanism and correction measures of the electrode signal were explored.

Polyvinylidene difluoride (PVDF) piezoelectric nanogenerators were prepared using high-voltage electrostatic spinning technology. The piezoelectric effect and sensing principle, pyroelectric effect and sensing principle of PVDF film were analyzed, and the finite element model of sensor and its equivalent circuit model were established. The flexible board made of polyimide film is used as the contact layer to realize multi-site signal sensing. Through the analysis of the piezoelectric and thermoelectric characteristics of the nanogenerator, the linear working area and the limit working state of the sensor are obtained. By establishing the mapping relationship between the piezoelectric /thermoelectric signals, the piezoelectric component and the thermoelectric component can be effectively extracted from the composite signal. Through the analysis of the signal response period and recovery period, the correction and decoupling of the composite signal are realized. The sensor electrode synchronization and signal interference tests were carried out, and the sensing errors caused by the sensor structure were analyzed. The prepared PVDF flexible multi-site tactile/thermal sensor can map external pressure/thermal radiation stimuli to output voltage/current signals, and dynamically observe the response distribution on the three-dimensional interface. It realizes image perception and dynamic target tracking, and records the two-dimensional trajectory of the tracked target at the same time. Human-machine interaction testing based on flexible sensors was carried out to realize human-machine motion recognition and tracking. Through the feedback control of the closed-loop system, the equivalent behavior trigger of the capacitive touch sensor and the flexible sensor of the intelligent robot is realized. The sensing error of the flexible sensor and the robot Hall rotation position sensor is small, and the remote signal feedback and behavior control of the intelligent robot are realized through wireless transmission equipment. The prepared flexible sensor has potential applications in the internet of things, health status detection and intelligent auxiliary equipment.