Underwater thrust and power generation using flexible piezoelectric composites: an experimental investigation toward self-powered swimmer-sensor platforms

Abstract

Fiber-based flexible piezoelectric composites offer several advantages to use in energy harvesting and biomimetic locomotion. These advantages include ease of application, high power density, effective bending actuation, silent operation over a range of frequencies, and light weight. Piezoelectric materials exhibit the well-known direct and converse piezoelectric effects. The direct piezoelectric effect has received growing attention for low-power generation to use in wireless electronic applications while the converse piezoelectric effect constitutes an alternative to replace the conventional actuators used in biomimetic locomotion. In this paper, underwater thrust and electricity generation are investigated experimentally by focusing on biomimetic structures with macro-fiber composite piezoelectrics. Fish-like bimorph configurations with and without a passive caudal fin (tail) are fabricated and compared. The favorable effect of having a passive caudal fin on the frequency bandwidth is reported. The presence of a passive caudal fin is observed to bring the second bending mode close to the first one, yielding a wideband behavior in thrust generation. The same smart fish configuration is tested for underwater piezoelectric power generation in response to harmonic excitation from its head. Resonant piezohydroelastic actuation is reported to generate milli-newton level hydrodynamic thrust using milli-watt level actuation power input. The average actuation power requirement for generating a mean thrust of 19 mN at 6 Hz using a 10 g piezoelastic fish with a caudal fin is measured as 120 mW. This work also discusses the feasibility of thrust generation using the harvested energy toward enabling self-powered swimmer-sensor platforms with comparisons based on the capacity levels of structural thin-film battery layers as well as harvested solar and vibrational energy.

A Review on Mechanisms for Piezoelectric-Based Energy Harvesters

“…That is why piezoelectric patches are widely used in various optical devices [71], space missions [10], biomedical devices [72], mechanical/civil structures [73], and precise measurement tools [74]. PEHs are preferred because of their flexibility, low electromagnetic interference, high positioning, and high torque-to-volume ratio [75,76]. A PEH is composed of three major components one, the piezoelectric patch that is responsible for converting environmental input (i.e., fluid structure interaction (FSI), biomechanical, vibration, etc.)…”

Numerical verification of the hydrodynamic reconstruction method for contact resonance atomic force microscopy

“…These advantages include: the reduction of van der Waals forces, 1,2 the elimination of capillary forces, 3,4 and the ability to image biological samples in domains that more closely resemble their native environments. 5 Additionally, the ability to accurately predict hydrodynamic forces acting on microstructures will benefit a wide range of applications including: microelectromechanical system (MEMS) design and operation, 6 energy harvesting, [7][8][9] and biomimetic propulsion. [9][10][11] The present work of estimating the hydrodynamic forces acting on cantilevered structures begins with Stokes, who developed the theory to estimate the forces acting on an infinite cylinder oscillating with small amplitude in an incompressible fluid.…”

“…5 Additionally, the ability to accurately predict hydrodynamic forces acting on microstructures will benefit a wide range of applications including: microelectromechanical system (MEMS) design and operation, 6 energy harvesting, [7][8][9] and biomimetic propulsion. [9][10][11] The present work of estimating the hydrodynamic forces acting on cantilevered structures begins with Stokes, who developed the theory to estimate the forces acting on an infinite cylinder oscillating with small amplitude in an incompressible fluid. 12 From this work, one can show that the natural frequency of oscillating structures drops dramatically when moving from air to liquid environments.…”

Ground-induced lift enhancement in a tandem of symmetric flapping wings: Lattice Boltzmann-immersed boundary simulations

“…In fact, such problem shows a lot of practical applications, such as the design of microair vehicles [1][2][3][4][5][6] or the improvement of the performance of underwater energy harvesters [7][8][9]. In the last decade, a lot of works developed aiming at dissecting the dynamics of flapping wings immersed in an unbounded quiescent viscous fluid by considering rigid [10][11][12][13], flexible [14][15][16][17][18][19][20], and even composite [21][22][23] structures.…”