This paper presents a novel passive control levitation system, termed electrostatic pneumatic hybrid levitation (EPHL), which primarily combines electrostatic attraction and compressed-air repulsion forces to create a new type of levitation system. During the levitation process, a pre-located disk was exposed to an electric field, resulting in charge polarization, which causes the electrostatic attraction force. Next, regulated compressed air was entered into the gap between the electrodes and the object, creating an air repulsion force. The EPHL system allows for adjusting the levitation gap by varying the compressed air pressure or the voltage applied to the electrodes. Furthermore, the EPHL system is capable of measuring the electrostatic force indirectly by placing the system similar to an air bearing and adding some mass. Moreover, the effect of air humidity on polarization time constant and electrostatic force was evaluated in the range of 21-29 RH. To investigate the affecting parameters (voltage and pressure), an experimental design based on response surface methodology (RSM) was conducted. The analysis of variance (ANOVA) revealed that both main parameters had a significant effect on the levitation gap, but not their squares or interaction. Besides, numerical simulation was carried out, and the results indicated good agreement between the simulation and the experiments. Experiments determined the maximum levitation gap and electrostatic force to be 320 mu m and 350 mN, respectively.
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