BEGIN:VCALENDAR VERSION:2.0 PRODID:-//wp-events-plugin.com//7.2.3.1//EN TZID:Europe/Paris X-WR-TIMEZONE:Europe/Paris BEGIN:VEVENT UID:6730@i2m.univ-amu.fr DTSTART;TZID=Europe/Paris:20200610T150000 DTEND;TZID=Europe/Paris:20200610T160000 DTSTAMP:20241120T201950Z URL:https://www.i2m.univ-amu.fr/evenements/bio-inspired-actuation-and-aqua tic-locomotion-using-piezoelectric-materials/ SUMMARY: (Georgia Institute of Technology\, USA): Bio-inspired actuation an d aquatic locomotion using piezoelectric materials DESCRIPTION:: This talk reviews our efforts over the past decade on bio-ins pired piezoelectric actuation and hydrodynamic thrust generation for aquat ic locomotion using fiber-based piezoelectric structures with interdigitat ed electrodes\, namely Macro-Fiber Composite (MFC) structures. Most piezoe lectric materials offer large actuation force but small deformation\, requ iring additional mechanisms for motion amplification. However\, MFCs inher ently strike a balance between the actuation force and deformation capabil ities\, offering high performance\, ease of fabrication\, geometric scalab ility\, robustness\, and silent operation. We describe three generations o f our relevant research\, starting with resonant mean thrust characterizat ion for a bimorph MFC fin in a quiescent water for the first bending mode\ , enabled by out-of-phase actuation of two vacuum-bonded MFC laminates. Th e effect of a passive fin extension on the thrust resultant is also discus sed over a wide frequency range covering the resonant dynamics. The second generation efforts include the first untethered piezoelectric swimmer in the literature\, with thrust levels similar to those of biological fish wi th similar dimensions. Distributed-parameter electromechanical model of th e piezoelectric fin is coupled with semi-empirical hydrodynamic loads from Morison’s equation for fins with different length-to-width aspect ratio s\, to identify inertia and drag coefficients. Vibration response is coupl ed with Lighthill’s equation for simple estimates of the mean thrust\, c onfirmed with experimental measurements. The third generation concept cont ains a streamlined untethered swimmer with 3D printed components\, tested both in a quiescent water and under imposed flow. Our early efforts toward actuation with multiple MFCs for 3D thrust vectoring are also discussed. Since piezoelectricity is reversible\, the multifunctional concept of usin g the swimmer as an energy harvester is summarized to generate electricity from underwater base excitation and vortex-induced vibrations. Modeling a nd analysis of nonlinear structural dynamics of MFC fins under large defor mations due to counteracting geometric and material nonlinearities are bri efly addressed.\nProf. Dr. Alper Erturk\, Georgia Institute of Technology\ , USA\nWoodruff Professor of Mechanical Engineering // Smart Structures an d Dynamical Systems Laboratory // G. W. Woodruff School of Mechanical Engi neering CATEGORIES:Interdisciplinary online seminar series on Biolocomotion END:VEVENT BEGIN:VTIMEZONE TZID:Europe/Paris X-LIC-LOCATION:Europe/Paris BEGIN:DAYLIGHT DTSTART:20200329T030000 TZOFFSETFROM:+0100 TZOFFSETTO:+0200 TZNAME:CEST END:DAYLIGHT END:VTIMEZONE END:VCALENDAR