  In this paper we study the self-propulsion of a triangular micro-robot (or
triangle-robot) which consists of three spheres connected by three rods; the
rods' lengths are changing independently and periodically. Using the asymptotic
procedure containing the two-timing method and distinguished limit arguments,
we obtain analytic expressions for self-propulsion velocity the angular
velocity. Our calculations show that a triangle-robot rotates with constant
angular velocity around its centroid, while the centroid moves in a circle. The
important special case of zero angular velocity represents rectilinear
translational self-propulsion with constant velocity.
