An underwater liquid supply unit includes a first bladder containing a first liquid, a second bladder containing a second liquid, and a third bladder containing a third liquid. The combined volume of the first liquid, second liquid, and third liquid is neutrally buoyant relative to a surrounding medium the liquid supply unit is disposed in (e.g., in seawater). As the first liquid, second liquid, and third liquid are dispensed from the bladders, the bladders may reduce in size in at least one dimension. As the liquids are dispensed, the liquids may be dispensed in a predetermined volumetric ratio based on the density of the liquids to maintain neutral buoyancy of the combined volume of liquid. The underwater liquid supply unit may also include an integrated generator such as a fuel cell, as well as a propeller.

A system and method by which energy from ocean waves is converted into hydrogen, and that hydrogen is used to manifest electrical and mechanical energies by an energy consuming device. A portion of the generated electrical power is communicated to water electrolyzers which produce oxygen and hydrogen from water as gases. At least a portion of the generated hydrogen gas is transferred to a transportation ship via a hose-carrying, remotely operated (or otherwise unmanned) vehicle, and subsequently transferred to an energy-consuming module or infrastructure, where a portion of the hydrogen is consumed in order to manifest a generation of electrical energy, a mechanical motion, and/or a chemical reaction.

A system and method by which energy from ocean waves is converted into hydrogen, and that hydrogen is used to manifest electrical and mechanical energies by an energy consuming device. A portion of the generated electrical power is communicated to water electrolyzers which produce oxygen and hydrogen from water as gases. At least a portion of the generated hydrogen gas is transferred to a transportation ship via a hose-carrying, remotely operated (or otherwise unmanned) vehicle, and subsequently transferred to an energy-consuming module or infrastructure, where a portion of the hydrogen is consumed in order to manifest a generation of electrical energy, a mechanical motion, and/or a chemical reaction.

A quadrotor UAV including ruggedized, integral-battery, load-bearing body, two arms on the load-bearing body, each arm having two rotors, a control module mounted on the load-bearing body, a payload module mounted on the control module, and skids configured as landing gear. The two arms are replaceable with arms having wheels for ground vehicle use, with arms having floats and props for water-surface use, and with arms having pitch-controlled props for underwater use. The control module is configured to operate as an unmanned aerial vehicle, an unmanned ground vehicle, an unmanned (water) surface vehicle, and an unmanned underwater vehicle, depending on the type of arms that are attached.

A quadrotor UAV including ruggedized, integral-battery, load-bearing body, two arms on the load-bearing body, each arm having two rotors, a control module mounted on the load-bearing body, a payload module mounted on the control module, and skids configured as landing gear. The two arms are replaceable with arms having wheels for ground vehicle use, with arms having floats and props for water-surface use, and with arms having pitch-controlled props for underwater use. The control module is configured to operate as an unmanned aerial vehicle, an unmanned ground vehicle, an unmanned (water) surface vehicle, and an unmanned underwater vehicle, depending on the type of arms that are attached.

A biomimetic robotic manta ray includes a head cabin, a central cabin, a pair of pectoral fins and a caudal fin cabin. The pectoral fin includes a crank-rocker mechanism and a bevel gear mechanism. The biomimetic robotic manta ray achieves undulatory propulsion through a coordinated periodic motion of the crank-rocker mechanism. A complex closed motion trail of the tail end of the pectoral fin of the manta ray is traced through the coordination of the bevel gear mechanism and the crank-rocker mechanism. The biomimetic robotic manta ray achieves a combined motion of two vertical undulations superimposed on the pectoral fin of a natural manta ray. The motion trail, which has an important effect on the efficient motion of the manta ray, of the tail end of the pectoral fin is approximately simulated.

A biomimetic robotic manta ray includes a head cabin, a central cabin, a pair of pectoral fins and a caudal fin cabin. The pectoral fin includes a crank-rocker mechanism and a bevel gear mechanism. The biomimetic robotic manta ray achieves undulatory propulsion through a coordinated periodic motion of the crank-rocker mechanism. A complex closed motion trail of the tail end of the pectoral fin of the manta ray is traced through the coordination of the bevel gear mechanism and the crank-rocker mechanism. The biomimetic robotic manta ray achieves a combined motion of two vertical undulations superimposed on the pectoral fin of a natural manta ray. The motion trail, which has an important effect on the efficient motion of the manta ray, of the tail end of the pectoral fin is approximately simulated.

An omnidirectional underwater vehicle includes an open-frame mechanism including a frame with top thrusters at four corners of a top end of the frame; mechanical arms disposed at a front end of the frame; and a rotary holder disposed in the frame and including a motor fixing plate, an upper bearing fixing plate and a lower bearing fixing plate. A cylindrical roller bearing is fixed between the upper bearing fixing plate and the lower bearing fixing plate, and an inner edge of the cylindrical roller bearing is provided with two bearing clip inner plates from top to bottom. A servo motor is fixed on the motor fixing plate, a bottom end of the bearing clip inner plate at the bottom is fixedly connected to a steering gear fixing plate, and a top end of the steering gear fixing plate is provided with fully waterproof steering gears installed with underwater thrusters.

An omnidirectional underwater vehicle includes an open-frame mechanism including a frame with top thrusters at four corners of a top end of the frame; mechanical arms disposed at a front end of the frame; and a rotary holder disposed in the frame and including a motor fixing plate, an upper bearing fixing plate and a lower bearing fixing plate. A cylindrical roller bearing is fixed between the upper bearing fixing plate and the lower bearing fixing plate, and an inner edge of the cylindrical roller bearing is provided with two bearing clip inner plates from top to bottom. A servo motor is fixed on the motor fixing plate, a bottom end of the bearing clip inner plate at the bottom is fixedly connected to a steering gear fixing plate, and a top end of the steering gear fixing plate is provided with fully waterproof steering gears installed with underwater thrusters.

Disclosed are a flexibly-driven small underwater robot and a driving method thereof. The underwater robot provided by the invention comprises a driving module and a propelling module. Two propelling modules are designed at head and tail portions, and the driving module is arranged between the two propelling modules. A rib plate in the driving module comprises a carbon fiber plate matrix and a piezoelectric fiber sheet; and a shape of the carbon fiber plate matrix is optimized by width change and hole digging. The propelling modules comprise a head propelling module and a tail propelling module, and the head propelling module and the tail propelling module are both propelled through a one-way valve. According to the invention, two modes of the pre-compression rib plate are adjusted through the piezoelectric fiber sheet, so that a volume of an internal cavity is changed, and jet propelling is carried out.