Study Of Nonlinear And Complex System On Nanopiezotronic

Many materials can output electric signal under externally applied strain,which behaviors are used by piezoelectric effect.Since Zhonglin Wang academician has ingeniously invented “nanogenerator” by applying ZnO nanoscale in 2006,the studies in nanomaterials and nanodevices,which both combine piezoelectric and semiconductor properties,have been a hot topic in the area of nanotechnology.Based on numerous experimental and theoretical researches,Wang Zhonglin created a new branch named piezotronics in nanotechnology.Piezotronics is used to adjust the transport characteristics of carrier,and changes electrical properties of piezoelectric semiconductor material by externally applied strain.These coupling effects between force and electricity and even optical excitation have great potential application value in nanobots and man-machine interactive system.Meanwhile,some new physical and chemical behaviors such as the nonlinear junction area modulation in piezoelectric semiconductor,higher conversion efficiency of surface piezoelectric electric field in nanoenergy package,can be explained using the nonlinear characteristics of piezoelectric charge.Bases on the novel piezoelectric semiconductor device and its nonlinear current-voltage characteristics,this paper originally introduces piezoelectric semiconductor device to design chaotic circuit,and uses nonlinear dynamical theory to study piezotronic transistor(chaotic)circuits.This study not only widens the application of the nonlinear and complex science,but it also provides a new research platform for the nonlinear and complex science.Furthermore,the nonlinear and complex science also provides a new thought for nanotechnology to further design high-sensitive devices.This paper,on the one hand,mainly discusses the chaotic circuit design using novel piezotronic devices,and presents the basic feature of the piezotronic transistor circuit.On the other hand,this paper also presents a possible attempt by applying the theory and methods of complex network to piezotronic flexible sensor network.In the first chapter,we briefly review the background and development of the nonlinear science and complex system,and introduce nonlinear chaotic circuit and complex network dynamics to study piezotronic.Meanwhile,we also review the development of piezoelectric devices and its latest progress in different areas.The discussion of theory framework,modeling and simulation of piezoelectric nonadevices based on classical semiconductor device physics is also presented.Chapter 2 discusses several typical chaotic circuits in nonlinear dynamics,and focuses main attentions on Chua's circuit,which comprises one important nonlinear resistance named Chua's diode to exhibit nonlinear dynamic behaviors,such as period and chaos.Then,replacing Chua's diode with piezotronic transistor in Chua's circuit,which current-voltage characteristics are reasonably reduced,we numerically analyze the circuit's working states by adjusting externally applied strain.Some complex dynamic behaviors such as double scroll chaotic attractor,single scroll chaotic attractor and various kinds of periodic state can be observed.Furthermore,the output signals of the piezotronic transistor circuit can be switched by periodically varying the externally applied strain,which can be used to tune/control nonlinear circuit states.Chapter 3 discusses the research background and the development of the complex network.Taking Kuramoto phase oscillator as an example,lots of different synchronization behaviors in the complex network,such as explosive synchronization,travelling wave and chimera are introduced.Considering that the exchange of communication and information in the piezotronic transistor sensor networks has potential correlation with the synchronization in complex network,we explore the travelling wave using bidirectional positive and negative coupling Kuramoto model.We mainly discuss the travelling wave in complex network,and find the condition behaving travelling wave in this system.Some further insights are given from the point of coupling effects.Finally,the dynamics in critical phase transition point are presented.