Fish-Like Self Propulsion Using Flexible Piezoelectric Composites

2012 ◽  
Author(s):  
Lejun Cen ◽  
Alper Erturk
Keyword(s):  
Smart Materials ◽  
Electromechanical Coupling ◽  
High Efficiency ◽  
Fiber Composite ◽  
Actuation Voltage ◽  
Robotic Fish ◽  
Circuit Board ◽  
Modeling Framework ◽  
Actuator Dynamics ◽  
Body Theory

The capacity of humankind to mimic fish-like locomotion for engineering applications depends mainly on the availability of suitable actuators. Researchers have recently focused on developing robotic fish using smart materials, particularly Ionic Polymer-Metal Composites (IPMCs), as a compliant, noise-free, and scalable alternative to conventional motor-based propulsion systems. In this paper, we investigate fish-like self propulsion using flexible bimorphs made of Macro-Fiber Composite (MFC) piezoelectric laminates. Similar to IPMCs, MFCs also exhibit high efficiency in size, energy consumption, and noise reduction. In addition, MFCs offer large dynamic forces in bending actuation, strong electromechanical coupling as well as both low-frequency and high-frequency performance capabilities. The experimental component of the presented work focuses on the characterization of an MFC bimorph propulsor for thrust generation in a quiescent fluid as well as the development of a preliminary robotic fish prototype incorporating a microcontroller and a printed-circuit-board (PCB) amplifier to generate high actuation voltage for battery-powered free locomotion. From the theoretical standpoint, a reliable modeling framework that couples the actuator dynamics, hydroelasticity, and fish locomotion theory is essential to both design and control of robotic fish. Therefore, a distributed-parameter electroelastic model with fluid effects and actuator dynamics is coupled with the elongated body theory. Both in-air and underwater experiments are performed to verify the incorporation of hydrodynamic effects in the linear actuation regime. For electroelastically nonlinear actuation levels, experimentally obtained underwater vibration response is coupled with the elongated body theory to predict the thrust output. Experiments are conducted to validate the electrohydroelastic modeling approach employed in this work and to characterize the performance of an MFC bimorph propulsor. Finally, a battery-powered preliminary robotic fish prototype is developed and tested in free locomotion.

scholarly journals Simulation Analysis of Bionic Robot Fish Based on MFC Materials

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Chengguang Zhang
Keyword(s):  
Smart Materials ◽  
Electromechanical Coupling ◽  
Mechanical Load ◽  
Fiber Composite ◽  
Smart Material ◽  
Robotic Fish ◽  
Electromechanical Coupling Coefficient ◽  
Control Analysis ◽  
Underwater Robots ◽  
New Type

With the development of marine resources, research on underwater robots has received unprecedented attention. The discovery and application of new smart materials provide new ideas for the research of underwater robots, which can overcome the issues of traditional underwater robots and optimize their design. A macro fiber composite (MFC) is a new type of piezoelectric fiber composite that combines actuators and sensors. The material has excellent deflection, good flexibility, and a high electromechanical coupling coefficient. Bionic mechatronics design is an effective way to innovate mechatronics in the future and can significantly improve mechatronics system performance. As an important issue for the design of bionic mechatronics, it is necessary to make robots as soft as natural organisms to achieve similar biological movement with both higher efficiency and performance. Compared with traditional rigid robots, the design and control of a soft robotic fish are difficult because the coupling between the flexible structure and the surrounding environment should be considered, which is difficult to solve due to the large deformation and coupling dynamics. In this paper, an MFC smart material is applied as an actuator in the design of bionic robotic fish. Combined with the piezoelectric constitutive and elastic constitutive equations of the MFC material, the voltage-drive signal is converted to a mechanical load applied to the MFC actuator, which makes the MFC material deform and drives the movement of the robotic fish. The characteristics of caudal fin motion during the swimming process of the bionic robotic fish were analyzed by an acoustic-solid coupling analysis method. The motion control analysis of the bionic robotic fish was carried out by changing the applied driving signal. Through numerical analysis, a new type of soft robotic fish was designed, and the feasibility of using an MFC smart material for underwater bionic robotic fish actuators was verified. The new soft robotic fish was successfully developed to achieve high performance.

Dynamic Modeling of Robotic Fish Caudal Fin With Electrorheological Fluid-Enabled Tunable Stiffness

2015 ◽  
Author(s):  
Sanaz Bazaz Behbahani ◽  
Xiaobo Tan
Keyword(s):  
Equations Of Motion ◽  
Electrorheological Fluid ◽  
Robotic Fish ◽  
Dynamic Equations ◽  
The Finite Element Method ◽  
Modeling Framework ◽  
Caudal Fin ◽  
Body Theory ◽  
Tunable Stiffness ◽  
Er Fluid

In this study, we investigate the modeling framework for a robotic fish actuated by a flexible caudal fin, which is filled with electrorheological (ER) fluid and thus enables tunable stiffness. This feature can be used in optimizing the robotic fish speed or maneuverability in different operating regimes. The robotic fish is assumed to be anchored and the flexible tail undergoes undulation activated by a servomotor at the base. Lighthill’s large-amplitude elongated-body theory is used to calculate the hydrodynamic force on the caudal fin, and Hamilton’s principle is used to derive the dynamic equations of motion of the caudal fin. The dynamic equations are then discritized using the finite element method, to obtain an approximate numerical solution. In particular, simulation is conducted to understand the influence of the applied electric field on the stiffness and thrust performance of the caudal fin.

Underwater Dynamic Actuation of Macro-Fiber Composite Flaps With Different Aspect Ratios: Electrohydroelastic Modeling, Testing, and Characterization

2014 ◽  
Author(s):  
Shima Shahab ◽  
Alper Erturk
Keyword(s):  
Electromechanical Coupling ◽  
Fiber Composite ◽  
Actuation Voltage ◽  
Metal Composite ◽  
Actuation Frequency ◽  
Aspect Ratios ◽  
Current Consumption ◽  
Macro Fiber Composite ◽  
Tip Velocity ◽  
Hydrodynamic Function

Macro-fiber composite (MFC) actuators offer simple and scalable design, robustness, noiseless performance, strong electromechanical coupling, and particularly a balance between the actuation force and deformation capabilities, which is essential to effective and agile biomimetic locomotion. Recent efforts in our lab have shown that MFC bimorphs with polyester electrode sheets can successfully be employed for fish-like aquatic locomotion in both tethered and untethered operation. MFC swimmers can outperform other smart material-based counterparts, such as the compliant ionic polymer-metal composite based swimmers, in terms of swimming speed per body length. Cantilevered flaps made of MFC bimorphs with different aspect ratios can be employed for underwater actuation, sensing, and power generation, among other aquatic applications of direct and converse piezoelectric effects. In an effort to develop linearized electrohydroelastic models for such cantilevers, the present work investigates MFC bimorphs with three different aspect ratios. The MFCs used in this study use the 33-mode of piezoelectricity with interdigitated electrodes. Underwater dynamic actuation frequency response functions (FRFs) of the MFCs are defined as the tip velocity per actuation voltage (tip velocity FRF) and current consumption per actuation voltage (admittance FRF). The tip velocity and admittance FRFs are modeled analytically for in-air actuation and validated experimentally for all aspect ratios. Underwater tip velocity and admittance FRFs are then derived by combining their in-air counterparts with corrected hydrodynamic functions. The corrected hydrodynamic functions are also identified from aluminum cantilevers of similar aspect ratios. Both tip vibration and current consumption per voltage input are explored. The failure of Sader’s hydrodynamic function for low length-to-width aspect ratios is shown. Very good correlation is observed between model simulations and experimental measurements using aspect ratio-dependent, corrected hydrodynamic function.

scholarly journals Coupling of experimentally validated electroelastic dynamics and mixing rules formulation for macro-fiber composite piezoelectric structures

2016 ◽  
Vol 28 (12) ◽  
pp. 1575-1588 ◽  
Author(s):  
Shima Shahab ◽  
Alper Erturk
Keyword(s):  
Power Generation ◽  
Composite Structures ◽  
Electromechanical Coupling ◽  
Fiber Composite ◽  
Rectangular Cross Section ◽  
Mixing Rules ◽  
Modeling Framework ◽  
Interdigitated Electrodes ◽  
Macro Fiber Composite ◽  
Piezoelectric Structures

Piezoelectric structures have been used in a variety of applications ranging from vibration control and sensing to morphing and energy harvesting. In order to employ the effective 33-mode of piezoelectricity, interdigitated electrodes have been used in the design of macro-fiber composites which employ piezoelectric fibers with rectangular cross section. In this article, we present an investigation of the two-way electroelastic coupling (in the sense of direct and converse piezoelectric effects) in bimorph cantilevers that employ interdigitated electrodes for 33-mode operation. A distributed-parameter electroelastic modeling framework is developed for the elastodynamic scenarios of piezoelectric power generation and dynamic actuation. Mixing rules (i.e. rule of mixtures) formulation is employed to evaluate the equivalent and homogenized properties of macro-fiber composite structures. The electroelastic and dielectric properties of a representative volume element (piezoelectric fiber and epoxy matrix) between two neighboring interdigitated electrodes are then coupled with the global electro-elastodynamics based on the Euler–Bernoulli kinematics accounting for two-way electromechanical coupling. Various macro-fiber composite bimorph cantilevers with different widths are tested for resonant dynamic actuation and power generation with resistive shunt damping. Excellent agreement is reported between the measured electroelastic frequency response and predictions of the analytical framework that bridges the continuum electro-elastodynamics and mixing rules formulation.

Bio-Inspired Robotic Fish Propelled by Multiple Artificial Fins

2016 ◽  
Author(s):  
Piqi Hou ◽  
Zhihang Ye ◽  
Zheng Chen
Keyword(s):  
Smart Materials ◽  
Robotic Fish ◽  
Circuit Board ◽  
Metal Composite ◽  
Ionic Polymer ◽  
Pectoral Fins ◽  
Polymer Metal ◽  
Programmable Circuit ◽  
Robot Fish ◽  
Biomimetic Robotic Fish

With advances in actuation and sensing, smart materials has drawn a growing attention from researchers in under water robotic fish. In this paper, a compact, noiseless, and untethered biomimetic robotic fish propelled by Ionic Polymer-Metal Composite (IPMC) actuators is developed. The robot fish employs two pectoral fins to generate steering and one caudal fin to generate main propulsion. A passive plastic fin is attached to the IPMC beam to enhance propulsion. With multiple IPMC fins, the fish is capable of 2D maneuvering. One small size programmable circuit board is designed for the 2D controllable fish. The Experimental results have shown that the forward-swimming speed can reach up to 1cm/sec and the both left-turning and right turning speed can reach up to 2 rad/sec.

Hybrid Actuation in Coupled Ionic / Conducting Polymer Devices

2003 ◽  
Vol 785 ◽  
Author(s):  
Matthew D. Bennett ◽  
Donald J. Leo
Keyword(s):  
Conducting Polymer ◽  
Smart Materials ◽  
Electromechanical Coupling ◽  
Performance Metrics ◽  
Polymer Membrane ◽  
Low Frequencies ◽  
Ionic Polymer ◽  
Polymer Actuators ◽  
Ionic Conducting ◽  
Initial Results

ABSTRACTIonic polymer membrane actuators represent a relatively new and exciting entry into the field of smart materials. Several key limitations of these transducers have prevented them from experiencing widespread use, however. For example, the bandwidth of these devices is limited at very low frequencies by characteristic relaxation and at high frequencies by the low elastic modulus of the polymer. In this paper, an overview of the initial results of work with hybrid ionic / conducting polymer actuators is presented. These hybrid actuators are devices that combine the electromechanical coupling of ionic polymer actuators and conducting polymer actuators into one coupled device. Initial results show that these hybrid devices have the potential to offer marked advantages over traditional ionic polymer membrane transducers, including increased stress and strain generation and higher actuation bandwidth. Details of the preparation of these devices and performance metrics are presented and comparisons to baseline materials are made.

scholarly journals Mobile-Phone Antenna Array with Diamond-Ring Slot Elements for 5G Massive MIMO Systems

Electronics ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 521 ◽  
Author(s):  
Naser Ojaroudi Parchin ◽  
Haleh Jahanbakhsh Basherlou ◽  
Mohammad Alibakhshikenari ◽  
Yasser Ojaroudi Parchin ◽  
Yasir I. A. Al-Yasir ◽  
...  
Keyword(s):  
Mobile Phone ◽  
Antenna Array ◽  
Massive Mimo ◽  
Printed Circuit Board ◽  
High Efficiency ◽  
Mimo Systems ◽  
Circuit Board ◽  
Slot Antenna ◽  
Impedance Bandwidth ◽  
Diamond Ring

A design of mobile-phone antenna array with diamond-ring slot elements is proposed for fifth generation (5G) massive multiple-input/multiple-output (MIMO) systems. The configuration of the design consists of four double-fed diamond-ring slot antenna elements placed at different corners of the mobile-phone printed circuit board (PCB). A low-cost FR-4 dielectric with an overall dimension of 75 × 150 mm2 is used as the design substrate. The antenna elements are fed by 50-Ohm L-shaped microstrip-lines. Due to the orthogonal placement of microstrip feed lines, the diamond-ring slot elements can exhibit the polarization and radiation pattern diversity characteristic. A good impedance bandwidth (S11 ≤ −10 dB) of 3.2–4 GHz has been achieved for each antenna radiator. However, for S11 ≤ −6 dB, this value is 3–4.2 GHz. The proposed design provides the required radiation coverage of 5G smartphones. The performance of the proposed MIMO antenna design is examined using both simulation and experiment. High isolation, high efficiency and sufficient gain-level characteristics have been obtained for the proposed MIMO smartphone antenna. In addition, the calculated total active reflection coefficient (TARC) and envelope correlation coefficient (ECC) of the antenna elements are very low over the whole band of interest which verify the capability of the proposed multi-antenna systems for massive MIMO and diversity applications. Furthermore, the properties of the design in Data-mode/Talk-mode are investigated and presented.

Fabrication and surface treatment of fine copper lines for HDI printed circuit board with modified full-additive method

Circuit World ◽  
2017 ◽  
Vol 43 (3) ◽  
pp. 131-138 ◽  
Author(s):  
Huirong He ◽  
Jida Chen ◽  
Shengtao Zhang ◽  
Minhui Liao ◽  
Lingxing Li ◽  
...  
Keyword(s):  
Printed Circuit Boards ◽  
High Efficiency ◽  
Oxidation Process ◽  
Optical Microscope ◽  
Circuit Board ◽  
Content Type ◽  
Printed Circuit ◽  
Additive Method ◽  
Fine Copper

Purpose This paper aims to propose a modified full-additive method (MFAM) to fabricate fine copper lines for high density interconnection (HDI) printed circuit boards (PCBs). In addition, the surface of the fine copper lines is treated with a brown oxidation process to obtain good adhesion between the copper and the dielectric resin. Design/methodology/approach Fine copper lines fabricated by MFAM were observed to evaluate the undercut quality, in comparison to undercut quality of copper lines fabricated by the semi-additive method and the subtractive method. The effect of the thickness of the dry film on the quality of the copper plating was investigated to obtain the regular shape of fine lines. The fine copper lines treated with the brown oxidation process were also examined to generate a coarse surface microstructure to improve the adhesion between the copper and the dielectric resin. The cross section and surface of as-fabricated fine copper lines were characterized using an optical microscope, a scanning electron microscope and an atomic force microscope. Findings MFAM has the potential to fabricate high-performance fine copper lines for HDI PCBs. Undercut of as-fabricated fine copper lines could be prevented to meet the design requirement of impedance. In addition, fine copper lines exhibit enough adhesive force to laminate with dielectric resin after the brown oxidation process. Originality/value MFAM, with the advantages of high efficiency and being a facile process, is developed to fabricate high-quality fine copper lines for industrial HDI PCB manufacture.

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