Advantages of electrostatic micromotor and its application to medical instruments

In this paper, electrostatic micromotor and conventional electromagnetic micromotor are compared. According to their different operation principles, the paper firstly analyzes the scaling effect of driving forces. Characteristic dimension L represents the linear scale of the micromotors. Electromagnetic driving force is proportional to high-order power of characteristic dimension L whereas electrostatic driving force is not. So, in micro domain, the effect of electrostatic force is larger than that of electromagnetic force, which makes electrostatic micromotor more competitive against electromagnetic alternative in MEMS. In assessing the performance of the micromotor, the power per unit volume and efficiency are the two most important criteria. Hence, the paper further compares the two kinds of micromotors from these two aspects. The results indicate that electrostatic micromotor has higher power per unit volume and efficiency, moreover, its structure is simple, it can be made sufficiently small. For those advantages of electrostatic micromotor, the paper finally discusses its application to medical instruments.