1 research outputs found
Magnetically actuated artificial microswimmers as mobile microparticle manipulators
Micro-scale swimming robots have been envisaged for many medical applications
such as targeted drug delivery, where the microrobot will be expected to
navigate in a fluid through channels carrying a payload. Alternatively, in many
cases, such a payload does not have to be physically bound to the swimmer, but
may be instead manipulated and steered through the channel by the microrobot.
We investigate this problem of contactless manipulation of a microparticle by
mobile microswimmer in a fluid at low Reynolds number. We consider a model of a
magnetically actuated artificial microswimmer, whose locomotion through a fluid
induces a disturbance velocity field in the fluid, that then acts to propel a
cargo particle in its vicinity. The problem investigated in this paper is
therefore one of coupled locomotion-manipulation of two bodies in a fluid. The
magnetic swimmer's motion is actuated by an externally applied magnetic field
of constant strength but whose direction rotates at a constant rate in a plane.
The swimmer propels itself in the direction perpendicular to this plane if the
frequency associated with the periodic magnetic field is above a critical
frequency. Below this critical frequency, the swimmer tumbles in place without
net locomotion. The coupled fluid-swimmer-cargo particle dynamics are solved
numerically using the method of Stokesian dynamics. The induced motion of the
cargo particle is shown to be controllable. This is achieved by switching the
planes of rotation of the magnetic field and switching frequency of the
magnetic field above and below the critical frequency. While a swimmer with a
specific geometry has been used in the model, the results of this paper are
applicable to swimmers with other geometries and means of propulsion. The
results of this paper show that microswimmers can be utilized as mobile
manipulators of microparticles in a fluid.Comment: 9 pages, 9 figures, To appear in proceedings of the 2019 ASME Dynamic
Systems and Controls Conferenc