Nature in Engineering for Monitoring the Oceans (NEMO): An isopycnal soft bodied approach for deep diving autonomous underwater vehicles

Taking inspiration from nature the NEMOdeep vehicle described in this paper is being developed as a laboratory demonstrator to showcase potential technologies to achieve small deep diving autonomous underwater vehicles. The design of the vehicle is a hybrid of conventional AUV components with engineered analogues of marine animal organs. The internal structure is comprised of a spine, ribs and sternum, which support a hydrodynamic fairing or `skin´. The `brain´ and actuators are developed using pressure tolerant electronics, negating the need for pressure vessels. The pressure tolerant electronics are surrounded by light mineral oil which transmits the hydrostatic pressure uniformly to the components while also providing buoyancy. The internal fluid is more compressible than seawater and the batteries and internal structure are less compressible than seawater: a `Buoyancy/Compressibility´ organ is being developed to passively maintain neutral buoyancy over the 0 to 6000m depth range.