Brennan T. Phillips

Soft Robotic Grippers for Biological Sampling on Deep Reefs.

Abstract This article presents the development of an underwater gripper that utilizes soft robotics technology to delicately manipulate and sample fragile species on the deep reef. Existing solutions for deep sea robotic manipulation have historically been driven by the oil industry, resulting in destructive interactions with undersea life. Soft material robotics relies on compliant materials that are inherently impedance matched to natural environments and to soft or fragile organisms. We demonstrate design principles for soft robot end effectors, bench-top characterization of their grasping performance, and conclude by describing in situ testing at mesophotic depths. The result is the first use of soft robotics in the deep sea for the nondestructive sampling of benthic fauna.

Deep-sea hydrothermal vents as natural egg-case incubators at the Galapagos Rift

The discovery of deep-sea hydrothermal vents in 1977 challenged our views of ecosystem functioning and yet, the research conducted at these extreme and logistically challenging environments still continues to reveal unique biological processes. Here, we report for the first time, a unique behavior where the deep-sea skate, Bathyraja spinosissima, appears to be actively using the elevated temperature of a hydrothermal vent environment to naturally “incubate” developing egg-cases. We hypothesize that this behavior is directly targeted to accelerate embryo development time given that deep-sea skates have some of the longest egg incubation times reported for the animal kingdom. Similar egg incubating behavior, where eggs are incubated in volcanically heated nesting grounds, have been recorded in Cretaceous sauropod dinosaurs and the rare avian megapode. To our knowledge, this is the first time incubating behavior using a volcanic source is recorded for the marine environment.

Shipboard design and fabrication of custom 3D-printed soft robotic manipulators for the investigation of delicate deep-sea organisms

Soft robotics is an emerging technology that has shown considerable promise in deep-sea marine biological applications. It is particularly useful in facilitating delicate interactions with fragile marine organisms. This study describes the shipboard design, 3D printing and integration of custom soft robotic manipulators for investigating and interacting with deep-sea organisms. Soft robotics manipulators were tested down to 2224m via a Remotely-Operated Vehicle (ROV) in the Phoenix Islands Protected Area (PIPA) and facilitated the study of a diverse suite of soft-bodied and fragile marine life. Instantaneous feedback from the ROV pilots and biologists allowed for rapid re-design, such as adding “fingernails”, and re-fabrication of soft manipulators at sea. These were then used to successfully grasp fragile deep-sea animals, such as goniasterids and holothurians, which have historically been difficult to collect undamaged via rigid mechanical arms and suction samplers. As scientific expeditions to remote parts of the world are costly and lengthy to plan, on-the-fly soft robot actuator printing offers a real-time solution to better understand and interact with delicate deep-sea environments, soft-bodied, brittle, and otherwise fragile organisms. This also offers a less invasive means of interacting with slow-growing deep marine organisms, some of which can be up to 18,000 years old.

In situ observations of the Meso-Bathypelagic Scyphozoan, Deepstaria enigmatica (Semaeostomeae: Ulmaridae)

ABSTRACT Deepstaria enigmatica (Semaeostomeae: Ulmaridae) is one of the largest and most mysterious invertebrate predators of the deep sea. Humans have encountered this jellyfish on only a few occasions and many questions related to its biology, distribution, diet, environmental tolerances, and behavior remain unanswered. In the 45 years since its formal description, there have been few recorded observations of D. enigmatica, due to the challenging nature of encountering these delicate soft-bodied organisms. Members of Deepstaria, which comprises two described species, D. enigmatica and D. reticulum, reside in the meso-bathypelagic region of the worlds oceans, at depths ranging from ∼600 to 1750 m. Here we report observations of a large D. enigmatica (68.3 cm length × 55.7 cm diameter) using a custom color high-definition low-light imaging system mounted on a scientific remotely operated vehicle (ROV). Observations were made of a specimen capturing or “bagging” prey, and we report on the kinetics of the closing motion of its membranelike umbrella. In the same area, we also noted a Deepstaria “jelly-fall” carcass with a high density of crustaceans feeding on its tissue and surrounding the carcass. These observations provide direct evidence of singular Deepstaria carcasses acting as jelly falls, which only recently have been reported to be a significant food source in the deep sea.

A Dexterous, Glove-Based Teleoperable Low-Power Soft Robotic Arm for Delicate Deep-Sea Biological Exploration

Modern marine biologists seeking to study or interact with deep-sea organisms are confronted with few options beyond industrial robotic arms, claws, and suction samplers. This limits biological interactions to a subset of “rugged” and mostly immotile fauna. As the deep sea is one of the most biologically diverse and least studied ecosystems on the planet, there is much room for innovation in facilitating delicate interactions with a multitude of organisms. The biodiversity and physiology of shallow marine systems, such as coral reefs, are common study targets due to the easier nature of access; SCUBA diving allows for in situ delicate human interactions. Beyond the range of technical SCUBA (~150 m), the ability to achieve the same level of human dexterity using robotic systems becomes critically important. The deep ocean is navigated primarily by manned submersibles or remotely operated vehicles, which currently offer few options for delicate manipulation. Here we present results in developing a soft robotic manipulator for deep-sea biological sampling. This low-power glove-controlled soft robot was designed with the future marine biologist in mind, where science can be conducted at a comparable or better means than via a human diver and at depths well beyond the limits of SCUBA. The technology relies on compliant materials that are matched with the soft and fragile nature of marine organisms, and uses seawater as the working fluid. Actuators are driven by a custom proportional-control hydraulic engine that requires less than 50 W of electrical power, making it suitable for battery-powered operation. A wearable glove master allows for intuitive control of the arm. The manipulator system has been successfully operated in depths exceeding 2300 m (3500 psi) and has been field-tested onboard a manned submersible and unmanned remotely operated vehicles. The design, development, testing, and field trials of the soft manipulator is placed in context with existing systems and we offer suggestions for future work based on these findings.

Rotary-actuated folding polyhedrons for midwater investigation of delicate marine organisms

A robot end effector uses one rotary actuator to fold the net of a dodecahedron, completely surrounding delicate mid-water organisms. Self-folding polyhedra have emerged as a viable design strategy for a wide range of applications, with advances largely made through modeling and experimentation at the micro- and millimeter scale. Translating these concepts to larger scales for practical purposes is an obvious next step; however, the size, weight, and method of actuation present a new set of problems to overcome. We have developed large-scale folding polyhedra to rapidly and noninvasively enclose marine organisms in the water column. The design is based on an axisymmetric dodecahedron net that is folded by an external assembly linkage. Requiring only a single rotary actuator to fold, the device is suited for remote operation onboard underwater vehicles and has been field-tested to encapsulate a variety of delicate deep-sea organisms. Our work validates the use of self-folding polyhedra for marine biological applications that require minimal actuation to achieve complex motion. The device was tested to 700 m, but the system was designed to withstand full ocean depth (11 km) pressures. We envision broader terrestrial applications of rotary-actuated folding polyhedra, ranging from large-scale deployable habitats and satellite solar arrays to small-scale functional origami microelectromechanical systems.