The present invention provides a hetero-stiffness robotic device with a central body portion having a head end and a tail end. A rigid rotatable head propeller extends from the head end while a flexible rotatable tail propeller extends from the tail end. A head motor positioned in the central body portion rotates the rigid rotatable head propeller and a tail motor positioned in the central body portion rotates the flexible rotatable tail propeller. A controller independently controls a rotational speed of the head motor and the tail motor. The head and tail propellers may have helical shapes. The hetero-stiffness propulsion gives the robotic device a high level of environmental adaptivity over a wide range of viscosities. The device demonstrates advantages in linearity, straightness, bi-directional locomotion ability, and efficiency, which provides a critical competence for moving in low Reynolds number environments.

The present invention provides a hetero-stiffness robotic device with a central body portion having a head end and a tail end. A rigid rotatable head propeller extends from the head end while a flexible rotatable tail propeller extends from the tail end. A head motor positioned in the central body portion rotates the rigid rotatable head propeller and a tail motor positioned in the central body portion rotates the flexible rotatable tail propeller. A controller independently controls a rotational speed of the head motor and the tail motor. The head and tail propellers may have helical shapes. The hetero-stiffness propulsion gives the robotic device a high level of environmental adaptivity over a wide range of viscosities. The device demonstrates advantages in linearity, straightness, bi-directional locomotion ability, and efficiency, which provides a critical competence for moving in low Reynolds number environments.

The invention relates to a fluid pump, in particular to a liquid pump having a rotor with at last one rotor blade for conveying the fluid, the rotor being variable with respect to its diameter between a first, compressed state and a second expanded state. In order to produce a simple compressibility and expandability of the rotor of the pump, it is provided according to the invention that at least one rotor blade is deformable between a first state which it assumes in the compressed state of the rotor and a second state which it assumes in the expanded state of the rotor by means of a fluid counterpressure during a rotation of the rotor during pump operation.

The invention relates to a fluid pump, in particular to a liquid pump having a rotor with at last one rotor blade for conveying the fluid, the rotor being variable with respect to its diameter between a first, compressed state and a second expanded state. In order to produce a simple compressibility and expandability of the rotor of the pump, it is provided according to the invention that at least one rotor blade is deformable between a first state which it assumes in the compressed state of the rotor and a second state which it assumes in the expanded state of the rotor by means of a fluid counterpressure during a rotation of the rotor during pump operation.

A vessel is provided herein which comprises a primary hull and at least two hull members capable of being deployed from or retracted into tunnels or underneath overhangs in the primary hull. In various embodiments, the vessel comprises a means for controllably deploying and retracting the hull members. These members may further comprise a propulsion means capable of propelling the vessel. In other embodiments the vessel comprises a failsafe mode allowing the hull members to fully retract into the vessel during times of destress. In various embodiments, the vessel is a landing craft capable of loading and unloading cargo without the burden of an overhang cross beam.

A vessel is provided herein which comprises a primary hull and at least two hull members capable of being deployed from or retracted into tunnels or underneath overhangs in the primary hull. In various embodiments, the vessel comprises a means for controllably deploying and retracting the hull members. These members may further comprise a propulsion means capable of propelling the vessel. In other embodiments the vessel comprises a failsafe mode allowing the hull members to fully retract into the vessel during times of destress. In various embodiments, the vessel is a landing craft capable of loading and unloading cargo without the burden of an overhang cross beam.

A peddle-actuated water propulsion device includes a seat with lower body harness, a support tube, a pair of crank-type pedals, and a propeller within a protective screen guard. The pedals are in mechanical communication with the propeller. The propeller is configured to accept a plurality of differently sized blades and may be positioned at a user-selected angle.

A peddle-actuated water propulsion device includes a seat with lower body harness, a support tube, a pair of crank-type pedals, and a propeller within a protective screen guard. The pedals are in mechanical communication with the propeller. The propeller is configured to accept a plurality of differently sized blades and may be positioned at a user-selected angle.

A human driven water propulsion apparatus includes a propeller and a human powered drive coupled to the propeller for driving the propeller. The propeller and human powered drive are connected to and supported by a chassis. Foot pedals are slidably engaged with the helical drive shafts. The helical drive shafts are connected to the propeller through one-way clutches and a gear train such that the propeller is driven by the helical drive shafts when driven by the pedals. In a watercraft application, the chassis is rotatably mounted for rotation between a first position where the propeller is faced in a forward direction and a second position where the propeller is faced in a rearward direction. In a swimmer application, a seat is attached to the chassis by a seat post and straps secure the seat to a user.