Recently, polymer materials have been at the forefront of other materials in building high-performance flexible electronic skin (e-skin) devices due to conspicuous advantages including excellent mechanical flexibility, good compatibility, and high plasticity. However, most research works just paid considerable attention and effort to the design, construction, and possible application of e-skins that reproduce the tactile perception of the human skin sensory system.Compared with tactile sensing devices, e-skins that aim to imitate the noncontact sensing features in the sensory system of human skin tend to avoid undesired issues such as bacteria spreading and mechanical wear. To further promote the development of e-skins to the human skin sensory system where tactile perception and non-contact sensing complement each other, significant progress and advances have been achieved in the field of polymer materials enabled e-skins for both tactile perception and non-contact sensing applications.In this review, the latest progress in polymer material-based e-skins with regard to tactile, non-contact sensing capabilities and their practical applications are introduced. The fabrication strategies of polymer materials and their role in building high-performance e-skins for tactile and non-contact sensing are highlighted. Furthermore, we also review the research works that integrated the polymer-based tactile and non-contact e-skins into robots and prostheses, smart gloves, and VR/AR devices and addressed some representative problems to demonstrate their suitability in practical applications in human-machine interactions. Finally, the current challenges in the construction of high-performance tactile and non-contact e-skins are highlighted and promising properties in this direction, by taking advantage of the polymer materials, are outlined.

The pressure resonance problem impelled by hydraulic pulsation power in piping networks is studied in this thesis. Through theoretical analyzing and computer simulating to the flow variation of multi-pulse sources accumulation, two concepts: the variable initial angle by equal probability and flow pulsation rare, are introduced. Some useful conclusions are also obtained. Most of piping networks vibration in engineering is aroused by the medium pressure pulsation. Destructive violent vibration is set off by the simulation of pressure pulsation when resonant occurred. In order to reduce the vibration, it is important to restrain pressure pulsation and to avoid the resonance areas determined by piping networks construction. On the basis of the optimized approximate model to meet the need of the practical engineering and fluidic network theory, this thesis is mainly concerned with the natural frequency of internal liquid vibration in pipelines. In this thesis a no-damping piping mathematics model as well as the transfer matrix method is employed, and the computer simulation is used in theoretical researching. The simulation software of pressure fluctuation for the complex fluidic transmission systems is developed. The effects of every structure parameters of simulated hydraulic pipelines on the pressure pulsation performance are analyzed in details by using the software which makes us modify some structure parameters efficiently so as to optimize structure, evade resonant, reduce the amplitude of pressure pulsation and avoid fluid resonance. The experiments verify the conclusion of the computer simulation and show that the software is easy to be widely used in the dynamic optimum design of fluid transmission systems.

In this paper, an applied classic control theory is adopted for the dynamics analysis for the electro-hydraulic servo drive device in which lower-powered integrative base on Matlab. The concrete measures are carried out to improve the dynamics of the system.

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