The RAD Sampler: Rotary-actuated folding polyhedrons for midwater investigation of delicate marine 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 polyhedral to rapidly and noninvasively enclose marine organisms in the water column. The Rotary Actuated Dodecahedron, or RAD Sampler, is a 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. The device was field-tested to 700 m, but the system was designed to withstand full ocean depth (11 km) pressures. Our work validates the use of self-folding polyhedra for marine biological applications that require minimal actuation to achieve complex motion. 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. This presentation will review the RAD Sampler design and testing phases and will present future directions in which this technology is enabling us to explore midwater biodiversity.