Organisms travelling in water always exploit some degree of body-shape variations to propel themselves; this may occur in the form of flapping of fins, beating of tails or whole-body ondulatory motions. First systematic observation of the relationship between body kinematics and thrust production were reported for fish and jellyfish and more recently various contribution have addressed the role of body-shape changes in the unsteady propulsion within a rigorous mathematical frame.Less studied, but of greater interest for the soft robotics community, is the case of those organisms which alter their body via volumetric pulsations or iso-volumetric cross sectional modifications. This is the case of squids and octopuses which, being for the most part devoid of prominent rigid parts, can perform extensive inflation and deflation of their bodies. We will discuss how organisms which subject themselves to volume collapse during translation can benefit from burst of speeds. This is achieved by exploiting not only the expulsion of mass from their body, but also from the recovery of kinetic energy, otherwise dissipated by viscosity, via the variation of added mass. This phenomenon has important implications in the design and control of soft-bodied underwater vehicles and marine energy harvesting devices.
|Publication status||Published - 1 Apr 2016|
|Event||Soft Robotics Week 2016: Trends, Applications and Challenges of Soft Robots - Grand Hotel Palazzo, Livorno, Italy|
Duration: 25 Apr 2016 → 30 Apr 2016
|Workshop||Soft Robotics Week 2016|
|Period||25/04/16 → 30/04/16|