Self-Activated Acoustical Swimmer and Functionality Comparison with Equivalent Hydrodynamic Swimmers: Spherical Model at Low Reynolds Number Condition

In this paper, a simple, practical and versatile model has been developed for a self-activated acoustic driven spherical swimmer that its surface may oscillate partially at dipole state (first mode of vibration). Regard to the nonlinear acoustic effects, the net acoustic radiation force exerted on the device is analytically derived and the non-zero states are approved. Considering hydrodynamics effects assuming low Reynolds number operating condition, the effects of active section angle and frequency of operation on the force, velocity and requirement power of swimmer are discussed. It is shown that comparing with many types of artificial and natural living matter swimmers, the swimming velocity of the developed model is satisfactory. The challenge of the random walk due to host medium fluctuations is discussed, and it is shown that the developed model can overcome the ubiquity of the Brownian motion, as well. Due to the simplicity of the developed model which leads to computing the swimmer features (such as force, velocity, etc.) analytically, this study can be considered for development of contact-free precise handling, drug distribution and delivery systems, entrapment technology of active carriers and the self-propulsive controllable devices which are essential in many engineering and medicine applications.