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In recent years, multi-axis robots are indispensable in automated factories due to the rapid development of Industry 4.0. Many related processes were required to have the increasing demand for accuracy, reproducibility, and abnormal detection. The monitoring function and immediate feedback for correction is more and more important. This present study integrated a highly sensitive lithium niobate (LiNbO3) vibration sensor as a sensor node (SN) and architecture of wireless mesh network (WMN) to develop a monitoring system (MS) for the robotic arm. The advantages of the thin-film LiNbO3 piezoelectric sensor were low-cost, high-sensitivity and good electrical compatibility. The experimental results obtained from the vibration platform show that the sensitivity achieved 50 mV/g and the reaction time within 1 ms. The results of on-site testing indicated that the SN could be configured on the relevant equipment quickly and detect the abnormal vibration in specific equipment effectively. Each SN could be used more than 10 h at the 80 Hz transmission rate under WMN architecture and the loss rate of transmission was less than 0.01% within 20 m.

We report the growth of high-quality AlN films on graphene. The graphene films were synthesized by CVD and then transferred onto silicon substrates. Epitaxial aluminum nitride films were deposited by DC magnetron sputtering on both graphene as an intermediate layer and silicon as a substrate. The structural characteristics of the AlN films and graphene were investigated. Highly c-axis-oriented AlN crystal structures are investigated based on the XRDpatterns observations.

The purpose of this study is to obtain the optimal operating condition in order to find the maximum supercritical CO2 heat extraction in the enhanced geothermal system (EGS). In this study, the heat transfer model conjugated with the Brinkman model is used to evaluate the thermal behavior in the reservoir of the EGS. This numerical model is validated by experiment. Optimization is processed based on the Nelder-Mead approach. The optimal operating conditions are proposed with different pressure, porosity. This study will build the optimal platform of heat source of geothermal power plant.

The purpose of this study is to find the heat transfer phenomena of CO2-EGS in the reservoir. The heat transfer model conjugated with the Brinkman model is used. This numerical model is validated by the experiment of supercritical CO2. The heat transfer coefficient of experiment is derived from the thermal resistance method of comparison between numerical model and experiment. Further, the heat transfer coefficients with different operating conditions are build in this study. This study will provide the better combination of operating conditions for the improved heat extraction.

Micro-actuator has applied on the microrobotics, microfluidics et al. widely. In general, to obtain the maximum output force is the designed requirement of electro-thermal actuator. However, the displacement for the force output will result in the stress concentration. The important issue is to reduce the failure of the electro-thermal actuator resulted from the stress concentration. This paper proposes an optimal process that involves using the finite element method and genetic algorithm to maximize the displacement and output force and minimize the stress concentration for enhancing the performance of an electro-thermal micro-actuator. The results were validated by comparing the simulated results of a previous study. Geometric design parameters were used for determining the displacement, output force, and stress concentration. The optimal design was proved to increase the life expectancy of micro-actuator.

The present study is intended to develop and test a cost-effective and efficient printing method for fabricating flexible metamaterial film with high electromagnetic wave absorptivity. The film can be easily applied to the surfaces with curved aspects. Firstly, numerical parametric study of the absorption characteristics of the film is performed for the range of frequency varying from 2.0 to 9.0 GHz based on commercial software package. Secondly, the flexible metamaterial films are fabricated, and experiments are conducted. The flexible metamaterial film consists of a flexible dielectric film made of polyimide (PI) and an array of split-ring resonators. The split-ring resonators of different geometric dimensions are fabricated on the PI film surface by using a silver nanoparticles ink jet printer. The performance of the flexible structure is then measured and dependence of operation frequency with higher absorptivity on the dimensions of the split-ring resonators is investigated. A comparison between the numerical and experimental data shows that the numerical predictions of the operation frequency with higher absorptivity closely agree with the experimental data.

A flexible proximity sensor fully fabricated by inkjet printing is proposed in this paper. The flexible proximity sensor is composed of a ZnO layer sandwiched in between a flexible aluminum sheet and a web-shaped top electrode layer. The flexible aluminum sheet serves as the bottom electrode. The material of the top electrode layer is nano silver. Both the ZnO and top electrode layers are deposited by inkjet printing. The fully inkjet printing process possesses the advantages of direct patterning and low-cost. It does not require photolithography and etching processes since the pattern is directly printed on the flexible aluminum sheet. The prototype demonstrates that the presented flexible sensor is sensitive to the human body. It may be applied to proximity sensing or thermal eradiation sensing.

The design of a micro multi-channel heat sink to achieve the minimum thermal resistance is the purpose of this study. The numerical package is employed by using the genetic algorithm to process the heat dissipation optimization of the micro multi-channel heat sink (the genetic algorithm employs the numerical package). The variables of this optimal design include channel number, channel aspect ratio and the ratio of channel width to pitch, as well as considering the weight of this micro channel heat sink in the optimal design process. Therefore, this optimization is a multi-objective function design. The results show that the thermal resistance is decreased as 0.144 W/K, and the weight of this micro channel heat sink can be decreased, individually or simultaneously.

The waste heat generated by high power LEDs is hardly effectively dissipated, therefore, it results in a serious problem in the luminous efficiency. The most important issue of the LED research is to find a potential design of heat removal and solve the problem of LED over-heating. The purpose of this study is to design the LEDs combined with the cooling module of the aluminum-acetone flat plate heat pipe by the experiment for the high efficiency of heat removal. The aluminum-acetone flat plate heat pipe is innovative proposed by our team. The high power LEDs with and without heat pipe cooling module is compared. The heat removal efficiency of the cooling module of the aluminum-acetone flat plate heat pipe reaches 77% and drops the junction temperature of LED about 36 °C. The cooling module of the aluminum-acetone flat plate heat pipe has proven to be effective in solving the heat concentration problems associated with the LED chips. In short, the phase change cooling module will apply on the electronic component of high heat concentration for more effective cooling method.