Electrostatic levitation under the single-axis feedback control condition

Abstract

An electrostatic levitator with a single-axis feedback control system was developed on the basis of electric field analysis and optimum design for levitation electrodes. In order to realize the stable levitation of various types of materials such as metals, inorganic materials and polymers, we made both experimental and theoretical investigations to solve the four key problems of electric field optimization, sample position detecting, sample charging control and levitation voltage minimization. Under the capacitive induction charging condition, a sample with the size of 2.6-4.5 mm usually bears positive charges amounting to 10 −9 Coulomb. Because the single-axis feedback control system responds quickly, it takes the levitated sample only 0.1 s from leaving the bottom electrode until attaining a stable levitation in the upright direction. The levitated sample displays satisfactory levitation stability in both the upright and the horizontal directions owing to the constraining force produced by spherical electrodes. electrostatic levitation, containerless processing, feedback control, space science PACS: 41.20.Cv, 61.25.Mv, 81.30.Fb

1D and 3D co-simulation and self-adaptive position control of electrostatic levitation in China’s Space Station

“…System dynamics simulation tools such as Simulink are usually used for modeling one dimensional (1D) complex control systems 11 , 19 due to the short computing time. Considering the lack of accuracy in 1D system model when estimating the electrostatic force between charged samples and high voltage electrodes 20 , 21 , performing a three dimensional (3D) electrostatic simulation to obtain an accurate electrical force could significantly improve the overall accuracy of 1D system model. Therefore, a coupled 1D and 3D co-simulation approach is very attractive considering their complementary advantages and is to be implemented in the present work.…”

Thermophysical properties and eutectic growth of electrostatically levitated and substantially undercooled liquid Zr91.2Si8.8 alloy

“…A sample of about 50 mg in weight was levitated in a high vacuum environment (∼10 −5 Pa) using electrostatic force via a feedback control system. The details of our ESL facility were described elsewhere [20]. The levitated sample was then heated by a continuous wave SPI SP300 fiber laser with the wavelength of 1070 nm, and cooled by turning off the laser power.…”

“…However, due to the physico-chemical contamination from container walls, it cannot extend the temperature range of properties to substantially undercooled regions by conventional methods. Containerless processing by electrostatic levitation (ESL) not only eliminates the heterogeneous nucleation from the container walls, but also exerts negligible disturbance to levitated liquid metal [18][19][20]. Therefore, it is very suitable for investigating the thermophysical properties and rapid eutectic growth of undercooled liquid alloy [21,22].…”

Electrostatic Levitation of Plant Seeds and Flower Buds

“…To investigate the containerless levitation process of plants in the electrostatic field, several kinds of seeds and flower buds are chosen to perform the experiments with an electrostatic levitator. [14] As shown in Fig. 1, the levitator consists of a top electrode plus a bottom electrode separated by a distance of ∼10 mm, which can produce an appropriate electrostatic field for levitation.…”