A method for producing star-shaped zinc oxide particles, the method including heating a solution containing tetrahydroxozincate ion Zn42\u2212, and diluting the solution containing tetrahydroxozincate ion Zn42\u2212 with a solvent in the course of reaction so that the concentration of zinc ion after the dilution is adjusted to 0. The aspiration chamber has a liquidgas separating structure. The hydraulic, mechanical or electricalelectronic direct timing systems that form the subject of the invention offer minimal resistance and minimal transmission.