Optimization of P-type poly-Si thermoelectric films design

Abstract

In this study, a polycrystalline silicon (poly-Si) film layer for micro thermoelectric generators (TEGs) was optimized by using Taguchi methods. An experimental plan using an orthogonal array L 9 (3 4 ) is described. The fabrication process of the thermoelectric poly-Si films layer is presented in detail. The P-type poly-Si films were fabricated on a tetra ethoxy silane (TEOS) layer with a supporting Si wafer. The thermoelectric properties, Seebeck coefficient and electrical conductivity were measured, including the transport properties such as the hall coefficient, hall mobility and carrier concentration. The design parameters were optimized based on the experimental results. Using the optimum values, a p-type poly-Si films layer was fabricated and its power factor was measured. The measured power factor was 541 μWm -1 K -2 , which was better than the predicted value of 221 μWm -1 K -2 .

Influence of Assembly Tolerance on Dynamic Characteristics of Motor Rotation Assembly

“…Furthermore, the rotor has a significant impact on the stiffness of the motor. If the rotor is assembled poorly on the spindle, the stiffness of the motor would fall behind expectation, the insufficient stiffness of the motor during high speed rotation will lead to its natural frequency falling within the range of operating frequencies [3]. This will cause the motor rotation assembly to produce resonance and fail to reach the highest rotation speed, even would reduce the service life of the motor.…”

Study on a Modifying Method of Finite Element Model for Analyzing the Shaft Rotation System

“…However, the machine assembly's operation tends to be steady after it exceeds this speed [2]. The critical speed of the shaft rotation system is obviously affected by these factors including the rotor's dimensions, the materials, the stiffness of bearings and the coupling [3,4]. Therefore, to avoid the resonance caused by the critical speed, an important research into the correct identification of critical speed and the dynamic parameters to ensure a safe speed range is necessary.…”