Abstract
Micromotors show many advantages in practical applications, including small size, large push-to-weight ratio, and low power consumption. Micromotors have been widely used in a variety of applications, including cell manipulation, payload delivery, and removal of toxic components. Among them, bubble-driven micromotors have received great attention due to their large driving force and high speed. The driving force of the bubble-driven micromotor movement comes from the four stages of the life cycle of the bubble: nucleation, growth, slip, and ejection. At present, investigators are still unclear about the driving mechanism of the bubble-driven micromotors, the source of the driving force being still especially controversial. In response to this problem, this paper combines the mass transfer model, hydrodynamic theory, and numerical simulation to explain the driving force generated by the various stages of the life-cycle of the bubble. A mass transfer model was used to calculate the driving force of the motor contributed by the bubble nucleation and slip stage. Based on equilibrium of force and conservation of energy, a theoretical model of the driving force of the tubular micromotor in the growth and ejection stage of the bubble was established. The results show that the driving force contributed by the bubble in the nucleation and the slip stage is rather small. However, the stage of bubble growth and ejection provide most of the driving force. On further evaluating the effect of the bubble driving force on the motor speed, it was found that the growth stage plays a major role in the motion of the bubble-driven micromotor. The micromotor velocity based on the driving forces of the full life-cycle of bubbles agrees well with the experimental results.
Highlights
Micromotors are micro-scale structures that exhibit many advantages in practical applications, including small size, large thrust-to-weight ratio, and low power consumption [1]
The dynamical behavior of the bubble plays a crucial role throughout the movement of the bubble-driven tubular micromotor
In this paper, based on the unclear problem of the driving mechanism of the bubble-driven micromotor, the theoretical model of the driving force of the motor in different stages was established by using mass transfer model, hydrodynamic theory, and numerical simulation
Summary
Micromotors are micro-scale structures that exhibit many advantages in practical applications, including small size, large thrust-to-weight ratio, and low power consumption [1]. The life cycle of bubble dynamics includes four stages, namely the nucleation, growth, slip, and ejection within the motor [14,15]. Fomin’s group [20] proposed that both bubble growth and ejection produced driving forces and established the corresponding theoretical models for prediction. The paper further proposed a model of driving force based on the tubular micromotor of the full life cycle of the bubble. In the slip stage of the bubble, the mass transfer model was used to establish the driving force of the motor. The driving force models of bubble nucleation, growth, slip, and ejection are established respectively, and the influence of bubble driving force on the motor motion is further evaluated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
