Abstract: A vibration-powered device adapted for flotation and propulsion on an upper surface in a liquid. The device having a body with a top side adapted to be at least partially disposed above the surface of the liquid, and a bottom side adapted to be at least partially submerged below the surface of the liquid. A vibration mechanism is disposed in the body. A propulsion fin is connected to the body. The fin includes a top side adapted to be disposed at least partially above the liquid surface, a bottom side adapted to be disposed at least partially below the surface. The vibration mechanism is adapted to oscillate the free distal end of the propulsion fin upward and downward.

Abstract: In one embodiment there is provided a shaft collar having a two component structure defined by a first component having a central bore for receipt of a shaft or axle and a second component positioned partially within the first component. The second component also having a relatively harder stiffness than the first component. The second component further includes a pair of opposing ribs positioned within the first component and about the central bore and a pair of C-shaped caps separately positioned against upper and lower ends of the pair of ribs and wherein the pair of opposing ribs have a height such that the at least a portion of the pair of C-shaped caps protrude from the upper and lower faces of the first component.

Abstract: A vibration-powered device adapted for flotation and propulsion on an upper surface in a liquid. The device having a body with a top side adapted to be at least partially disposed above the surface of the liquid, and a bottom side adapted to be at least partially submerged below the surface of the liquid. A vibration mechanism is disposed in the body. A propulsion fin is connected to the body. The fin includes a top side adapted to be disposed at least partially above the liquid surface, a bottom side adapted to be disposed at least partially below the surface. The vibration mechanism is adapted to oscillate the free distal end of the propulsion fin upward and downward.

Abstract: A vibration-powered device adapted for flotation and propulsion on an upper surface in a liquid. The device having a body with a top side adapted to be at least partially disposed above the surface of the liquid, and a bottom side adapted to be at least partially submerged below the surface of the liquid. A vibration mechanism is disposed in the body. A propulsion fin is connected to the body. The fin includes a top side adapted to be disposed at least partially above the liquid surface, a bottom side adapted to be disposed at least partially below the surface. The vibration mechanism is adapted to oscillate the free distal end of the propulsion fin upward and downward.

Abstract: In one embodiment there is provided a shaft collar having a two component structure defined by a first component having a central bore for receipt of a shaft or axle and a second component positioned partially within the first component. The second component also having a relatively harder stiffness than the first component. The second component further includes a pair of opposing ribs positioned within the first component and about the central bore and a pair of C-shaped caps separately positioned against upper and lower ends of the pair of ribs and wherein the pair of opposing ribs have a height such that the at least a portion of the pair of C-shaped caps protrude from the upper and lower faces of the first component.

Abstract: A playset system for autonomous devices includes a communal area including a substantially horizontal and substantially planar area bounded by a plurality of side walls, a plurality of connectors, and a plurality of ports. Each port is disposed in a side wall, each port is situated adjacent to one of the connectors, and each port includes a gate adapted to open and close, to impede movement of the autonomous devices when closed, and to allow passage of the autonomous devices when open.