In accordance with at least one aspect of this disclosure, a crustacean trap can include a cage configured to trap one or more crustaceans, and a propulsion system connected to the cage and configured to provide propulsion to the cage. In certain embodiments, the trap can include a controller configured to control the propulsion system to autonomously pilot the trap.

An underwater energy harvesting drone has a primary hull to be submersibly received in ocean water and a plurality of thermoelectric modules, each module of said plurality of thermoelectric modules having a first operational interface in thermal contact with the primary hull. A thermal transfer element is in contact with a second operational interface on the plurality of thermoelectric modules and an electrical power storage device is connected to the plurality of thermoelectric modules. Positioning of the submersible primary hull to create a thermal gradient between the primary hull and the thermal transfer element induces electrical power generation by the thermoelectric modules thereby charging the electrical power storage device.

An underwater energy harvesting drone has a primary hull to be submersibly received in ocean water and a plurality of thermoelectric modules, each module of said plurality of thermoelectric modules having a first operational interface in thermal contact with the primary hull. A thermal transfer element is in contact with a second operational interface on the plurality of thermoelectric modules and an electrical power storage device is connected to the plurality of thermoelectric modules. Positioning of the submersible primary hull to create a thermal gradient between the primary hull and the thermal transfer element induces electrical power generation by the thermoelectric modules thereby charging the electrical power storage device.

An unmanned vehicle including a vehicle body, a propulsion system, a maneuvering system, a vehicle control system, a buoyancy control system, a sensor system, and at least one power supply is disclosed. The propulsion system, maneuvering system, vehicle control system, buoyancy control system, sensor system, and power supply are carried by the vehicle body. The sensor system includes a sensor adapted to detect an item of interest and provide an item of interest signal to the vehicle control system. The vehicle control system is adapted to receive the item of interest signal, identify an item of interest classification and provide a classification signal. The classification signal is determined by the item of interest classification and is utilized by the propulsion system, maneuvering system, vehicle control system, or buoyancy control system to avoid physical, electrical, acoustic, or thermal detection of the unmanned vehicle by the item of interest.

A system of connectable aerial vehicles. The system includes a plurality of aerial vehicles that each include a platform, one or more rotors operatively connected to the platform, and a power source that supplies power to the one or more rotors. The plurality of aerial vehicles are configured to operate in air, and operate in water while connected to form a floating platform. The floating platform is configured to support an object with at least a portion of each of the plurality of aerial vehicles configured to form a segment of the floating platform.

A submergible aerial vehicle with one or more rotors, a body operatively connected to the one or more rotors, and a platform operatively connected to the body. The vehicle is configured to operate with one or more additional vehicles such that the platform of each vehicle connects together and forms a segment of an enlarged floating platform. The enlarged platform is configured to support an object above the water. The body includes a cavity that is able to be at least partially filled with fluid. The cavity causes the submergible aerial vehicle to be at least partially submerged in a body of water.

A submergible aerial vehicle with one or more rotors, a body operatively connected to the one or more rotors, and a platform operatively connected to the body. The vehicle is configured to operate with one or more additional vehicles such that the platform of each vehicle connects together and forms a segment of an enlarged floating platform. The enlarged platform is configured to support an object above the water. The body includes a cavity that is able to be at least partially filled with fluid. The cavity causes the submergible aerial vehicle to be at least partially submerged in a body of water.

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.

Underwater Deployable Structures (UDSs) capable of achieving inflation via mechanical pumps, moisture-activated expanding foams, water swelling material, or a hybrid of a mechanical pump and water swelling material. Moisture expanding foams begin as polyurethane-based resins of low viscosity, and react in the presence of water to become solid foam. In their final forms, the foams exist as open- or closed-cell, and vary in strength, elasticity, and rigidity. Water swelling material is also disclosed wherein the water swelling material is capable of achieving expansion numerous (e.g., up to about 250) times its initial volume when in contact with water and can shrink back to its initial volume upon dehydration, making the UDSs reusable. A mechanical pump may optionally be used to assist in initial inflation until the water swelling material reaches full expansion.