scholarly journals Development of High-Performance Soft Robotic Fish by Numerical Coupling Analysis

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Wenjing Zhao ◽  
Aiguo Ming ◽  
Makoto Shimojo
Keyword(s):  
High Performance ◽  
Fiber Composite ◽  
Swimming Performance ◽  
Structural Parameters ◽  
Robotic Fish ◽  
Dynamic Responses ◽  
Flexible Structure ◽  
Swimming Velocity ◽  
Coupling Analysis ◽  
And Control

To design a soft robotic fish with high performance by a biomimetic method, we are developing a soft robotic fish using piezoelectric fiber composite (PFC) as a flexible actuator. Compared with the conventional rigid robotic fish, the design and control of a soft robotic fish are difficult due to large deformation of flexible structure and complicated coupling dynamics with fluid. That is why the design and control method of soft robotic fish have not been established and they motivate us to make a further study by considering the interaction between flexible structure and surrounding fluid. In this paper, acoustic fluid-structural coupling analysis is applied to consider the fluid effect and predict the dynamic responses of soft robotic fish in the fluid. Basic governing equations of soft robotic fish in the fluid are firstly described. The numerical coupling analysis is then carried out based on different structural parameters of soft robotic fish. Through the numerical analysis, a new soft robotic fish is finally designed, and experimental evaluation is performed. It is confirmed that the larger swimming velocity and better fish-like swimming performance are obtained from the new soft robotic fish. The new soft robotic fish is developed successfully for high performance.

Electricity-structure-fluid coupled modelling and experiment of underwater flexible structure with partially distributed macro fiber composites

2020 ◽  
pp. 107754632097691
Author(s):  
Junqiang Lou ◽  
Tehuan Chen ◽  
Yiling Yang ◽  
Chao Xu ◽  
Hairong Chen ◽  
...  
Keyword(s):  
Mode Shape ◽  
Fiber Composite ◽  
Coupled Model ◽  
Experimental Results ◽  
Dynamic Responses ◽  
Flexible Structure ◽  
Flexible Beam ◽  
Coupled Modelling ◽  
Hydrodynamic Damping ◽  
Macro Fiber Composite

Dynamic oscillating behavior of the flexible structure immerged in viscous fluids has attracted growing attention and been widely used in various practical applications. A general electricity-structure-fluid coupled model for the forced dynamic responses of a cantilever immersed in fluids, with partially distributed macro fiber composite, is proposed in this paper. Based on the classical Euler–Bernoulli beam theory, the first mass-normalized mode shape of the cantilever with partially bonded macro fiber composite is determined using assumed mode method. The attachment of the macro fiber composite actuators stiffens the macro fiber composite-bonded portion of the cantilever. The established mode shape matches perfectly with experimental results. Considering the macro fiber composite actuator as a set of representative elements connected in parallel, the internally actuation moment provided by the macro fiber composite actuators is obtained. The hydrodynamic load caused by the surrounding fluids, decomposed into the added mass and hydrodynamic damping parts, is also added to the theoretical model in the frequency-domain form. The predicted in-air and underwater dynamic behaviors of the flexible beam are consistent with the experimental results at different auction levels. Thus, the obtained general electricity-structure-fluid coupled model can be used to predict the forced dynamic responses of flexible structure with partially bonded actuators immersed in fluids.

A biomimetic cownose ray robot fish with oscillating and chordwise twisting flexible pectoral fins

2015 ◽  
Vol 42 (3) ◽  
pp. 214-221 ◽  
Author(s):  
Hongwei Ma ◽  
Yueri Cai ◽  
Yuliang Wang ◽  
Shusheng Bi ◽  
Zhao Gong
Keyword(s):  
Swimming Performance ◽  
Robotic Fish ◽  
Small Radius ◽  
Water Tank ◽  
Pectoral Fin ◽  
Content Type ◽  
Pectoral Fins ◽  
Propulsion Performance ◽  
Cownose Ray ◽  
And Control

Purpose The paper aims to develop a cownose ray-inspired robotic fish which can be propelled by oscillating and chordwise twisting pectoral fins. Design/methodology/approach The bionic pectoral fin which can simultaneously realize the combination of oscillating motion and chordwise twisting motion is designed based on analyzing the movement of cownose ray’s pectoral fins. The structural design and control system construction of the robotic fish are presented. Finally, a series of swimming experiments are carried out to verify the effectiveness of the design for the bionic pectoral fin. Findings The experimental results show that the deformation of the bionic pectoral fin can be well close to that of the cownose ray’s. The bionic pectoral fin can produce effective angle of attack, and the thrust generated can propel robotic fish effectively. Furthermore, the tests of swimming performance in the water tank show that the robotic fish can achieve a maximum forward speed of 0.43 m/s (0.94 times of body length per second) and an excellent turning maneuverability with a small radius. Originality/value The oscillating and pitching motion can be obtained simultaneously by the active control of chordwise twisting motion of the bionic pectoral fin, which can better imitate the movement of cownose ray’s pectoral fin. The designed bionic pectoral fin can provide an experimental platform for further study of the effect of the spanwise and chordwise flexibility on propulsion performance.

scholarly journals Transfer of Dry-Land Resistance Training Modalities to Swimming Performance

2020 ◽  
Vol 74 (1) ◽  
pp. 195-203
Author(s):  
Jerzy Sadowski ◽  
Andrzej Mastalerz ◽  
Wilhelm Gromisz
Keyword(s):  
Resistance Training ◽  
Repeated Measures ◽  
Swimming Performance ◽  
Swimming Velocity ◽  
Training Experience ◽  
Dry Land ◽  
Significance Level ◽  
Training Interventions ◽  
And Control ◽  
Training Modalities

Abstract A great number of studies focusing on the effects of dry-land resistance training interventions on swimming performance remain inconclusive. It is suggested that transferability of dry-land strength gains to swimming performance appear when dry-land resistance training programs are swim-specific. The main aim of this study was to compare the effects of specific dry-land resistance training on an ergometer with traditional dry-land exercises, and to determine how much of the resistance training effects were transferred to specific swimming conditions. The study included a group of 26 youth competitive male swimmers (age 15.7 ± 0.5 years, height 174.6 ± 6.6 cm, weight 68.4 ± 8.2 kg, training experience 5.8±0.7 years) of regional level. They were randomly allocated to one of two groups: experimental (E) and control (T). Both groups were involved in a 12-week dry-land resistance training concentrated on increasing muscular strength and power output of the upper limbs. Group E used a specialized ergometer (JBA – Zbigniew Staniak), while group T performed traditional resistance exercises. The program consisted of 10 sets of 30 s of exercise with 30 s rest intervals between each set. A two-way repeated measures ANOVA with Tukey HSD post hoc comparisons was used to determine if any significant differences existed between training groups across pretest and posttest conditions. The significance level was set at p ≤ 0.05. Dry-land resistance training modalities were the only differences in training between both groups. Our findings show that rates of transfer are much higher in group E than in group T, which resulted in a significant increase in swimming velocity (by 4.32%, p<0.001; ES=1.23, and 2.78%, p<0.003, ES=0.31, respectively).

Transition of Neural Signals on Cylindrical Shells With Various Curvatures

2005 ◽  
Author(s):  
J. G. DeHaven ◽  
Y. Han ◽  
H. S. Tzou
Keyword(s):  
Cylindrical Shell ◽  
High Performance ◽  
Cylindrical Shells ◽  
Free Vibration Analysis ◽  
Dynamic Responses ◽  
Neural Signals ◽  
Natural Modes ◽  
Shell Panel ◽  
Membrane Strain ◽  
And Control

Sensing and control are essential to achieving the high performance and high precision of modern aerospace structures and systems. Typical off-the-shelf sensors placed at discrete locations usually add additional weights and thus often influence dynamic responses of precision systems. Unlike the conventional discrete add-on sensors, thin lightweight piezoelectric layers can be spatially spread and distributed over the surfaces of precision structures. The purpose of this study is to investigate microscopic neural signal generations from infinitesimal piezoelectric neurons over a cylindrical shell panel of various curvature angles and to determine dominating signal components resulting from longitudinal or circumferential membrane strains or longitudinal or circumferential bending strains. Dynamic equations of cylindrical shells are defined first, followed by free-vibration analysis. Then, mode shape functions and modal spatial strain distributions are used to determine the signal generation of distributed neuron sensors laminated on a linear cylindrical shell panel. The microscopic signal generations of infinitesimal piezoelectric sensors or neurons are investigated for three different curvature angles, i.e., β* = 30°, 90°, and 150°, of a simply-supported cylindrical shell panel. Evaluating these three cases suggests that as the curvature increases from 0° to 360°, the neural signals from the membrane strain dominate for lower natural modes before the neural signals from the bending strain become dominating as the mode increases.

Characterization of a Multifunctional Bioinspired Piezoelectric Swimmer and Energy Harvester

2020 ◽  
Author(s):  
Yu-Cheng Wang ◽  
Eetu Kohtanen ◽  
Alper Erturk
Keyword(s):  
Energy Harvesting ◽  
Large Scale ◽  
Energy Harvester ◽  
Fiber Composite ◽  
Swimming Performance ◽  
Water Channel ◽  
Robotic Fish ◽  
Water Tank ◽  
Base Excitation ◽  
Piezoelectric Energy

Abstract Fiber-based flexible piezoelectric composites with interdigitated electrodes, namely Macro-Fiber Composite (MFC) structures, strike a balance between the deformation and actuation force capabilities for effective underwater bio-inspired locomotion. These materials are also suitable for vibration-based energy harvesting toward enabling self-powered electronic components. In this work, we design, fabricate, and experimentally characterize an MFC-based bio-inspired swimmer-energy harvester platform. Following in vacuo and in air frequency response experiments, the proposed piezoelectric robotic fish platform is tested and characterized under water for its swimming performance both in free locomotion (in a large water tank) and also in a closed-loop water channel under imposed flow. In addition to swimming speed characterization under resonant actuation, hydrodynamic thrust resultant in both quiescent water and under imposed flow are quantified experimentally. We show that the proposed design easily produces thrust levels on the order of biological fish with similar dimensions. Overall it produces thrust levels higher than other smart material-based designs (such as soft material-based concepts), while offering geometric scalability and silent operation unlike large scale robotic fish platforms that use conventional and bulky actuators. The performance of this untethered swimmer platform in piezoelectric energy harvesting is also quantified by underwater base excitation experiments in a quiescent water and via vortex induced-vibration (VIV) experiments under imposed flow in a water channel. Following basic resistor sweep experiments in underwater base excitation experiments, VIV tests are conducted for cylindrical bluff body configurations of different diameters and distances from the leading edge of the energy harvesting tail portion. The resulting concept and design can find use for underwater swimmer and sensor applications such as ecological monitoring, among others.

scholarly journals Ultrahigh-Q Tunable Terahertz Absorber Based on Bulk Dirac Semimetal with Surface Lattice Resonance

Photonics ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 22
Author(s):  
Zhiyong Wang ◽  
Yanghong Ou ◽  
Shiyu Wang ◽  
Yanzi Meng ◽  
Zi Wang ◽  
...  
Keyword(s):  
Quality Factor ◽  
High Performance ◽  
Structural Parameters ◽  
Resonance Wavelength ◽  
Metamaterial Absorber ◽  
Terahertz Absorber ◽  
Dirac Semimetal ◽  
Surface Lattice ◽  
And Control ◽  
Quality Factor Q

In this paper, we present an easy-to-implement metamaterial absorber based on bulk Dirac semimetal (BDS). The proposed device not only obtains an ultrahigh quality factor (Q-factor) of 4133 and dynamic adjustability at high absorption, but also exhibits an excellent sensing performance with a figure of merit (FOM) of 4125. These outstanding properties are explained by the surface lattice resonance, which allows us to improve the quality factor significantly and control resonance wavelength precisely by tuning the unit cell periods, Fermi energy of the BDS, and structural parameters. Our findings can provide high-performance applications in terahertz filtering, detection, and biochemical sensing.

scholarly journals Reduction of Polycyclic Aromatic Hydrocarbons (PAHs) in Sesame Oil Using Cellulosic Aerogel

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 644
Author(s):  
Do-Yeong Kim ◽  
Boram Kim ◽  
Han-Seung Shin
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
High Performance ◽  
Oil Quality ◽  
Acid Value ◽  
Quality Parameters ◽  
Sesame Oil ◽  
Miscanthus Sinensis ◽  
Polycyclic Aromatic ◽  
And Control

The effect of cellulosic aerogel treatments used for adsorption of four polycyclic aromatic hydrocarbons (PAHs)—benzo[a]anthracene, chrysene, benzo[b]fluoranthene, and benzo[a]pyrene [BaP])—generated during the manufacture of sesame oil was evaluated. In this study, eulalia (Miscanthus sinensis var. purpurascens)-based cellulosic aerogel (adsorbent) was prepared and used high performance liquid chromatography with fluorescence detection for determination of PAHs in sesame oil. In addition, changes in the sesame oil quality parameters (acid value, peroxide value, color, and fatty acid composition) following cellulosic aerogel treatment were also evaluated. The four PAHs and their total levels decreased in sesame oil samples roasted under different conditions (p < 0.05) following treatment with cellulosic aerogel. In particular, highly carcinogenic BaP was not detected after treatment with cellulosic aerogel. Moreover, there were no noticeable quality changes in the quality parameters between treated and control samples. It was concluded that eulalia-based cellulosic aerogel proved suitable for the reduction of PAHs from sesame oil and can be used as an eco-friendly adsorbent.

Advanced high-performance processing tools for diagnostics and control in fusion devices

2021 ◽  
Vol 170 ◽  
pp. 112529
Author(s):  
N. Cruz ◽  
A.J.N. Batista ◽  
J.M. Cardoso ◽  
B.B. Carvalho ◽  
P.F. Carvalho ◽  
...  
Keyword(s):  
High Performance ◽  
Diagnostics And Control ◽  
And Control

scholarly journals Detection of Antimicrobial Residues in Poultry Litter: Monitoring a Risk through a Selective and Sensitive HPLC–MS/MS Method

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1399
Author(s):  
Karina Yévenes ◽  
Ekaterina Pokrant ◽  
Lina Trincado ◽  
Lisette Lapierre ◽  
Nicolás Galarce ◽  
...  
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Poultry Litter ◽  
Chromatography Tandem Mass Spectrometry ◽  
Antimicrobial Residues ◽  
Field Samples ◽  
Liquid Chromatography Tandem Mass ◽  
Commercial Poultry ◽  
Agriculture Fertilizer ◽  
And Control

Tetracyclines, sulphonamides, and quinolones are families of antimicrobials (AMs) widely used in the poultry industry and can excrete up to 90% of AMs administrated, which accumulate in poultry litter. Worryingly, poultry litter is widely used as an agriculture fertilizer, contributing to the spread AMs residues in the environment. The aim of this research was to develop a method that could simultaneously identify and quantify three AMs families in poultry litter by high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). Samples of AMs free poultry litter were used to validate the method according to 657/2002/EC and VICH GL49. Results indicate that limit of detection (LOD) ranged from 8.95 to 20.86 μg kg−1, while limits of quantitation (LOQ) values were between 26.85 and 62.58 µg kg−1 of tetracycline, 4-epi-tetracycline, oxytetracycline, 4-epi-oxytetracycline, enrofloxacin, ciprofloxacin, flumequine, sulfachloropyridazine, and sulfadiazine. Recoveries obtained ranged from 93 to 108%. The analysis of field samples obtained from seven commercial poultry flocks confirmed the adequacy of the method since it detected means concentrations ranging from 20 to 10,364 μg kg−1. This provides us an accurate and reliable tool to monitor AMs residues in poultry litter and control its use as agricultural fertilizer.

scholarly journals Exploring the Structure–Performance Relationship of Sulfonated Polysulfone Proton Exchange Membrane by a Combined Computational and Experimental Approach

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 959
Author(s):  
Cataldo Simari ◽  
Mario Prejanò ◽  
Ernestino Lufrano ◽  
Emilia Sicilia ◽  
Isabella Nicotera
Keyword(s):  
High Performance ◽  
Mechanical Stability ◽  
Structural Parameters ◽  
Hydration Number ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Water Dynamics ◽  
Mechanical Resistance ◽  
Theoretical Simulation ◽  
Sulfonated Polysulfone

Sulfonated Polysulfone (sPSU) is emerging as a concrete alternative to Nafion ionomer for the development of proton exchange electrolytic membranes for low cost, environmentally friendly and high-performance PEM fuel cells. This ionomer has recently gained great consideration since it can effectively combine large availability on the market, excellent film-forming ability and remarkable thermo-mechanical resistance with interesting proton conductive properties. Despite the great potential, however, the morphological architecture of hydrated sPSU is still unknown. In this study, computational and experimental advanced tools are combined to preliminary describe the relationship between the microstructure of highly sulfonated sPSU (DS = 80%) and its physico-chemical, mechanical and electrochemical features. Computer simulations allowed for describing the architecture and to estimate the structural parameters of the sPSU membrane. Molecular dynamics revealed an interconnected lamellar-like structure for hydrated sPSU, with ionic clusters of about 14–18 Å in diameter corresponding to the hydrophilic sulfonic-acid-containing phase. Water dynamics were investigated by 1H Pulsed Field Gradient (PFG) NMR spectroscopy in a wide temperature range (20–120 °C) and the self-diffusion coefficients data were analyzed by a “two-sites” model. It allows to estimate the hydration number in excellent agreement with the theoretical simulation (e.g., about 8 mol H2O/mol SO3− @ 80 °C). The PEM performance was assessed in terms of dimensional, thermo-mechanical and electrochemical properties by swelling tests, DMA and EIS, respectively. The peculiar microstructure of sPSU provides a wider thermo-mechanical stability in comparison to Nafion, but lower dimensional and conductive features. Nonetheless, the single H2/O2 fuel cell assembled with sPSU exhibited better features than any earlier published hydrocarbon ionomers, thus opening interesting perspectives toward the design and preparation of high-performing sPSU-based PEMs.

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