Contactless magnetic couplings for microfluidic devices and nautical propulsion

A device for moving a fluid with magnetic gear, comprising:

• a first shaft that is configured to be rotatable;
• two first balls each having a shape of a first sphere, respectively fixed to the first shaft through a center of each first sphere, each of the first balls having a first magnetic dipole in a direction orthogonal to the first shaft and a center of each of the first magnetic dipoles coincides with the center of the corresponding first sphere through which the first shaft penetrates;
• a second shaft that is freely rotatable and that is disposed in parallel with the first shaft;
• and
• a second ball having a shape of a second sphere, fixed to the second shaft through a center of the second sphere of the second ball, the second ball having a second magnetic dipole in a direction orthogonal to the second shaft with a center of the second magnetic dipole coinciding with the center of the second sphere through which the second shaft penetrates,
• wherein the respective centers of the two first balls and the center of the second ball are arranged so as to form an isosceles triangle with a vertex angle being defined about the center of the second ball and satisfying
• ψ
• =
• 2
• ⁢
• arcsin
• ⁡
• (
• 1
• 3
• )
• ≈
• 70.53
• ⁢
• °
• and so that the two first balls and the second ball form a contactless magnetic gear, transmitting a rotational force of the first shaft to the second shaft, and
• wherein at least one of the second shaft and the second ball is physically connected to a blade structure that is placed in a passage of the fluid so that when the first shaft is rotated by an external driving force, the resulting rotation of the second shaft moves the fluid by said blade structure.