Electrowetting display (EWD) is one of the latest and most promising reflective displays. However, some defects are easily caused in a driving process. For example, the aperture ratio of pixels can be reduced due to oil splitting, and the grayscale cannot be stabilized due to charge trapping. These defects can be effectively solved by designing driving waveforms for EWDs. So, a power function driving waveform was proposed in this paper, which consisted of an oil splitting suppression stage, a direct current (DC) driving stage and an oil stabilization stage. Firstly, the relationships among luminance values, power constants and driving time were measured. An optimal oil splitting suppression stage was obtained, which could effectively inhibit oil splitting. Then, the response time could be reduced by a DC voltage in the DC driving stage. Finally, a voltage slope was tested during the oil stabilization stage, which was used to counteract voltage created by the charge trapping. The experimental results showed that compared with a linear function waveform, the response time could be shortened by 16.1%, and the luminance value could be increased by 3.8%. The aperture ratio and oil stability of EWD can be effectively improved by these findings, thereby increasing its potential application in the display field.

In order to solve the optimization problem of the disk magnetic coupler, the two optimization schemes, the orthogonal test and multiobjective genetic algorithm, were used to optimize the disk magnetic coupler to maximize the magnetic torque while reducing the eddy current loss, and then the correctness of the optimization results was verified by electromagnetic simulation experiments. The eddy current loss and magnetic torque of the optimized disk magnetic coupler were normalized by using the comprehensive evaluation function. After orthogonal test and multiobjective genetic algorithm optimization, the comprehensive evaluation value of the disk magnetic coupler increased by 2.43 times and 3.30 times, respectively, and the optimization effect of multiobjective genetic algorithm is more significant. The relative errors between theoretical and simulated values of the maximum magnetic torque and eddy current loss by multiobjective genetic algorithm are 2.22%–4.72% and 1.13%–6.41%, respectively, suggesting that the optimization method is feasible. The research results show that the multiobjective genetic algorithm optimization can significantly improve the performance of magnetic disk coupler, which can provide theoretical and technical basis for the design of disk magnetic coupler.

To enhance the comprehensive thermal-hydraulic performance of microchannel heat sinks (MCHS), this work proposed a novel open-type MCHS integrated with front triangular ribs and secondary channels. Firstly, numerical computations were carried out to compare the flow and heat transfer characteristics of seven distinct MCHS configurations, and identify the optimal hybrid geometry consisting of an open microchannel fitted with integrated front triangular ribs and secondary channels. Secondly, the effects of H₁ (height of open front triangular ribs) and H₂ (height of open secondary channels) on the thermal-hydraulic performance of the MCHS were systematically analyzed. The results revealed that the composite open MCHS obtained its peak performance evaluation criterion (PEC) value at H₁ = 0.15 mm and H₂ = 0.25 mm from separate single-factor parametric analyses for H₁ and H₂, at a mass flow rate of 0.9 g/s. Finally, a surrogate model correlating three structural parameters (H₁, H₂, W_w) with the optimization objective (PEC) was established based on orthogonal test data. This surrogate model was coupled with a genetic algorithm to perform global parameter optimization to maximize PEC. Relative to the original design and the reference geometry in other literature, the optimized design achieved maximum reductions of 15.3% in thermal resistance and 70.9% in pumping power, accompanied by a 55.7% improvement in PEC. This research provides theoretical support for the structural design of high-heat-flux microchannel cooling devices.