A mobile robot generally including a first suction module, a second suction module and a hinge assembly pivotably connecting the suction modules together. Each of the suction modules includes a support frame defining a vacuum chamber and a vacuum unit supported on the support frame and communicating with the vacuum chamber. The vacuum unit includes a rotating impeller and an exhaust cowling surrounding the impeller. The impeller has an axis of rotation and is adapted to draw air from the vacuum chamber into the impeller in a direction generally parallel to the impeller axis of rotation and to discharge the drawn air in a direction substantially perpendicular to the impeller axis of rotation. The exhaust cowling is adapted to redirect the discharged air, whereby a thrusting force is applied to the support frame in a direction opposite of the direction of the drawn air from the vacuum chamber.