- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Hybrid Laser Ablation and Chemical Modification for Fast Fabrication of Bio-inspired Super-hydrophobic Surface with Excellent Self-cleaning, Stability and Corrosion Resistance
摘要： Although laser ablation is considered as a facile technique to fabricate bio-inspired super-hydrophobic surfaces, the issue is that the initial laser treated metallic surfaces show super-hydrophilic property. It will take a long period to reach super-hydrophobic state under ambient air. It is reported that these super-hydrophobic surfaces could be easily damaged by thermal heating effect or interaction with other liquids, causing uncontrolled loss of super-hydrophobicity. In this study, a stable super-hydrophobic aluminum surface was rapidly fabricated via the hybrid laser ablation and surface chemical modification of (heptadecafluoro-1, 1, 2, 2-tetradecyl) triethoxysilane (AC-FAS). Surface morphology and chemistry were systematically investigated to explore the generation mechanism of super-hydrophobicity. The water contact angle of the treated surfaces can reach up to 160.6? ± 1.5? with rolling angle of 3.0? ± 1.0?, exhibiting perfect self-cleaning capability, long-term stability, and excellent chemical stability in acidic as well as alkaline solutions. The potentiodynamic polarization tests implied that the super-hydrophobic surfaces showed better anti-corrosion performance. This hybrid laser ablation and surface chemical modification are very time-saving and low-cost, which offers a rapid way for quantity production of super-hydrophobic surface on aluminum material.
关键词： nanosecond laser,bioinspiration,corrosion resistance,chemical stability,self-cleaning,super-hydrophobic,long-term stability
更新于2025-09-23 15:22:29
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Inkjet Printing and Characterization of Titanium Dioxide and Platinum Electrodes For Dye-sensitized Solar Cells (DSSCs)
摘要： We have bridged the unsteady and steady mechanisms of underwater propulsion in nature and engineering by colocating their flapping and steady lifting surfaces in an outwardly conventional propulsor. The feasibility is indicated by the observation of overlap in the mechanisms in propulsion density versus displacement volume from 0.1 to 1 m . Such an overlap also exists between natural and engineered flyers. A novel, 0.7-m diameter, propulsor has been built where the fins, twistable along their span (0 to 30 ), can either slosh (where roll, pitch, and twist of the fins vary independently) or spin (where the rotational rate, fin pitch, and twist vary independently). Here, we discuss the origin of the novelty of the propulsor, the production of small thrust by slosh and propeller (prop) modes, the control of thrust amplitude by spanwise twisting of the fin, and the abrupt reversing of thrust. The tow speeds are low and close to the minimum induced velocity required for thrust onset by the flapping mechanism in the present propulsor—0 to 0.09 m/s, the fin chord 8, 250, and Reynolds number and shaft input power being 1 W. Time-averaged measurements show that thrust is more sensitive to pitch amplitude than to twisting during hovering, an effect that is reversed during slow towing due to the reduction in the spanwise variation of angle of attack. During towing, twist is more effective in the slosh mode than in the prop mode. Steady and quasi-steady thrust modeling is done to compare with prop- and slosh-mode measurements, respectively. The departures of the models are interpreted to mean that the beneficial effects of twist on the leading edge vortex (LEV) augment slosh forces and the rotational effects are detrimental to prop forces. We present simultaneous videography of fins during twisting and thrust reversal, and of thrust time trace as direct evidence of the relationship of cause and effect. Spanwise fin twisting is used to show that near-zero levels of thrust (0 to 1 N in steps of approximately 0.1 N) can be produced in both the slosh and prop modes and can be controlled merely by twisting the fins while keeping all other fin parameters unchanged. Transient-free reversal of the thrust direction has been achieved in the slosh mode while maintaining the same absolute value of thrust. However, thrust reversal in the prop mode is not transient free. This prop-mode transient is weaker due to the change in sign of the pitch angle but a change in the direction of the hub rotation produces a large spike and the reasons are discussed. Fine thrust control with individual fin hydrodynamics at the source that involves the lowest change in inertia is smoother. Smooth thrust reversibility is clearly identified as a unique property of flapping fin hydrodynamics. The mechanism overlap occurs because both fin modes have similar low transitional Reynolds numbers. Dynamical system models of unsteady hydrodynamics and control are shown to be similar suggesting that animal swimmers control vortex shedding ion-by-ion and animal-like motion control is theoretically possible with the proposed propulsor in the slosh mode but not in the prop mode.
关键词： hydrodynamics,oscillating propulsor,nonlinear control,force transient,Bioinspiration
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE 16th India Council International Conference (INDICON) - Rajkot, India (2019.12.13-2019.12.15)] 2019 IEEE 16th India Council International Conference (INDICON) - Design of two-element Circularly Polarized Bubbled Antenna for Vehicular Communication
摘要： We have bridged the unsteady and steady mechanisms of underwater propulsion in nature and engineering by colocating their flapping and steady lifting surfaces in an outwardly conventional propulsor. The feasibility is indicated by the observation of overlap in the mechanisms in propulsion density versus displacement volume from 0.1 to 1 m . Such an overlap also exists between natural and engineered flyers. A novel, 0.7-m diameter, propulsor has been built where the fins, twistable along their span (0 to 30 ), can either slosh (where roll, pitch, and twist of the fins vary independently) or spin (where the rotational rate, fin pitch, and twist vary independently). Here, we discuss the origin of the novelty of the propulsor, the production of small thrust by slosh and propeller (prop) modes, the control of thrust amplitude by spanwise twisting of the fin, and the abrupt reversing of thrust. The tow speeds are low and close to the minimum induced velocity required for thrust onset by the flapping mechanism in the present propulsor—0 to 0.09 m/s, the fin chord 8, 250, and Reynolds number and shaft input power being 1 W. Time-averaged measurements show that thrust is more sensitive to pitch amplitude than to twisting during hovering, an effect that is reversed during slow towing due to the reduction in the spanwise variation of angle of attack. During towing, twist is more effective in the slosh mode than in the prop mode. Steady and quasi-steady thrust modeling is done to compare with prop- and slosh-mode measurements, respectively. The departures of the models are interpreted to mean that the beneficial effects of twist on the leading edge vortex (LEV) augment slosh forces and the rotational effects are detrimental to prop forces. We present simultaneous videography of fins during twisting and thrust reversal, and of thrust time trace as direct evidence of the relationship of cause and effect. Spanwise fin twisting is used to show that near-zero levels of thrust (0 to 1 N in steps of approximately 0.1 N) can be produced in both the slosh and prop modes and can be controlled merely by twisting the fins while keeping all other fin parameters unchanged. Transient-free reversal of the thrust direction has been achieved in the slosh mode while maintaining the same absolute value of thrust. However, thrust reversal in the prop mode is not transient free. This prop-mode transient is weaker due to the change in sign of the pitch angle but a change in the direction of the hub rotation produces a large spike and the reasons are discussed. Fine thrust control with individual fin hydrodynamics at the source that involves the lowest change in inertia is smoother. Smooth thrust reversibility is clearly identified as a unique property of flapping fin hydrodynamics. The mechanism overlap occurs because both fin modes have similar low transitional Reynolds numbers. Dynamical system models of unsteady hydrodynamics and control are shown to be similar suggesting that animal swimmers control vortex shedding ion-by-ion and animal-like motion control is theoretically possible with the proposed propulsor in the slosh mode but not in the prop mode.
关键词： oscillating propulsor,Bioinspiration,hydrodynamics,nonlinear control,force transient
更新于2025-09-23 15:19:57
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[IEEE 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Paris, France (2019.9.1-2019.9.6)] 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Conical vs Gaussian Terahertz Emission from Two-Color Laser-Induced Air Plasma Filaments
摘要： We have bridged the unsteady and steady mechanisms of underwater propulsion in nature and engineering by colocating their flapping and steady lifting surfaces in an outwardly conventional propulsor. The feasibility is indicated by the observation of overlap in the mechanisms in propulsion density versus displacement volume from 0.1 to 1 m . Such an overlap also exists between natural and engineered flyers. A novel, 0.7-m diameter, propulsor has been built where the fins, twistable along their span (0 to 30 ), can either slosh (where roll, pitch, and twist of the fins vary independently) or spin (where the rotational rate, fin pitch, and twist vary independently). Here, we discuss the origin of the novelty of the propulsor, the production of small thrust by slosh and propeller (prop) modes, the control of thrust amplitude by spanwise twisting of the fin, and the abrupt reversing of thrust. The tow speeds are low and close to the minimum induced velocity required for thrust onset by the flapping mechanism in the present propulsor—0 to 0.09 m/s, the fin chord 8, 250, and Reynolds number and shaft input power being 1 W. Time-averaged measurements show that thrust is more sensitive to pitch amplitude than to twisting during hovering, an effect that is reversed during slow towing due to the reduction in the spanwise variation of angle of attack. During towing, twist is more effective in the slosh mode than in the prop mode. Steady and quasi-steady thrust modeling is done to compare with prop- and slosh-mode measurements, respectively. The departures of the models are interpreted to mean that the beneficial effects of twist on the leading edge vortex (LEV) augment slosh forces and the rotational effects are detrimental to prop forces. We present simultaneous videography of fins during twisting and thrust reversal, and of thrust time trace as direct evidence of the relationship of cause and effect. Spanwise fin twisting is used to show that near-zero levels of thrust (0 to 1 N in steps of approximately 0.1 N) can be produced in both the slosh and prop modes and can be controlled merely by twisting the fins while keeping all other fin parameters unchanged. Transient-free reversal of the thrust direction has been achieved in the slosh mode while maintaining the same absolute value of thrust. However, thrust reversal in the prop mode is not transient free. This prop-mode transient is weaker due to the change in sign of the pitch angle but a change in the direction of the hub rotation produces a large spike and the reasons are discussed. Fine thrust control with individual fin hydrodynamics at the source that involves the lowest change in inertia is smoother. Smooth thrust reversibility is clearly identified as a unique property of flapping fin hydrodynamics. The mechanism overlap occurs because both fin modes have similar low transitional Reynolds numbers. Dynamical system models of unsteady hydrodynamics and control are shown to be similar suggesting that animal swimmers control vortex shedding ion-by-ion and animal-like motion control is theoretically possible with the proposed propulsor in the slosh mode but not in the prop mode.
关键词： hydrodynamics,oscillating propulsor,nonlinear control,force transient,Bioinspiration
更新于2025-09-19 17:13:59
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[IEEE 2019 Systems of Signal Synchronization, Generating and Processing in Telecommunications (SYNCHROINFO) - Russia (2019.7.1-2019.7.3)] 2019 Systems of Signal Synchronization, Generating and Processing in Telecommunications (SYNCHROINFO) - Simulation of Readiness Coefficient of FOCL with Temperature Actions on Optical Fibers
摘要： We have bridged the unsteady and steady mechanisms of underwater propulsion in nature and engineering by colocating their flapping and steady lifting surfaces in an outwardly conventional propulsor. The feasibility is indicated by the observation of overlap in the mechanisms in propulsion density versus displacement volume from 0.1 to 1 m . Such an overlap also exists between natural and engineered flyers. A novel, 0.7-m diameter, propulsor has been built where the fins, twistable along their span (0 to 30 ), can either slosh (where roll, pitch, and twist of the fins vary independently) or spin (where the rotational rate, fin pitch, and twist vary independently). Here, we discuss the origin of the novelty of the propulsor, the production of small thrust by slosh and propeller (prop) modes, the control of thrust amplitude by spanwise twisting of the fin, and the abrupt reversing of thrust. The tow speeds are low and close to the minimum induced velocity required for thrust onset by the flapping mechanism in the present propulsor—0 to 0.09 m/s, the fin chord 8, 250, and Reynolds number and shaft input power being 1 W. Time-averaged measurements show that thrust is more sensitive to pitch amplitude than to twisting during hovering, an effect that is reversed during slow towing due to the reduction in the spanwise variation of angle of attack. During towing, twist is more effective in the slosh mode than in the prop mode. Steady and quasi-steady thrust modeling is done to compare with prop- and slosh-mode measurements, respectively. The departures of the models are interpreted to mean that the beneficial effects of twist on the leading edge vortex (LEV) augment slosh forces and the rotational effects are detrimental to prop forces. We present simultaneous videography of fins during twisting and thrust reversal, and of thrust time trace as direct evidence of the relationship of cause and effect. Spanwise fin twisting is used to show that near-zero levels of thrust (0 to 1 N in steps of approximately 0.1 N) can be produced in both the slosh and prop modes and can be controlled merely by twisting the fins while keeping all other fin parameters unchanged. Transient-free reversal of the thrust direction has been achieved in the slosh mode while maintaining the same absolute value of thrust. However, thrust reversal in the prop mode is not transient free. This prop-mode transient is weaker due to the change in sign of the pitch angle but a change in the direction of the hub rotation produces a large spike and the reasons are discussed. Fine thrust control with individual fin hydrodynamics at the source that involves the lowest change in inertia is smoother. Smooth thrust reversibility is clearly identified as a unique property of flapping fin hydrodynamics. The mechanism overlap occurs because both fin modes have similar low transitional Reynolds numbers. Dynamical system models of unsteady hydrodynamics and control are shown to be similar suggesting that animal swimmers control vortex shedding ion-by-ion and animal-like motion control is theoretically possible with the proposed propulsor in the slosh mode but not in the prop mode.
关键词： hydrodynamics,oscillating propulsor,nonlinear control,force transient,Bioinspiration
更新于2025-09-19 17:13:59
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Symmetrical Bi-Heterojunction Alternating Current Ultraviolet Light-Emitting Diode
摘要： We have bridged the unsteady and steady mechanisms of underwater propulsion in nature and engineering by colocating their flapping and steady lifting surfaces in an outwardly conventional propulsor. The feasibility is indicated by the observation of overlap in the mechanisms in propulsion density versus displacement volume from 0.1 to 1 m . Such an overlap also exists between natural and engineered flyers. A novel, 0.7-m diameter, propulsor has been built where the fins, twistable along their span (0 to 30 ), can either slosh (where roll, pitch, and twist of the fins vary independently) or spin (where the rotational rate, fin pitch, and twist vary independently). Here, we discuss the origin of the novelty of the propulsor, the production of small thrust by slosh and propeller (prop) modes, the control of thrust amplitude by spanwise twisting of the fin, and the abrupt reversing of thrust. The tow speeds are low and close to the minimum induced velocity required for thrust onset by the flapping mechanism in the present propulsor—0 to 0.09 m/s, the fin chord 8, 250, and Reynolds number and shaft input power being 1 W. Time-averaged measurements show that thrust is more sensitive to pitch amplitude than to twisting during hovering, an effect that is reversed during slow towing due to the reduction in the spanwise variation of angle of attack. During towing, twist is more effective in the slosh mode than in the prop mode. Steady and quasi-steady thrust modeling is done to compare with prop- and slosh-mode measurements, respectively. The departures of the models are interpreted to mean that the beneficial effects of twist on the leading edge vortex (LEV) augment slosh forces and the rotational effects are detrimental to prop forces. We present simultaneous videography of fins during twisting and thrust reversal, and of thrust time trace as direct evidence of the relationship of cause and effect. Spanwise fin twisting is used to show that near-zero levels of thrust (0 to 1 N in steps of approximately 0.1 N) can be produced in both the slosh and prop modes and can be controlled merely by twisting the fins while keeping all other fin parameters unchanged. Transient-free reversal of the thrust direction has been achieved in the slosh mode while maintaining the same absolute value of thrust. However, thrust reversal in the prop mode is not transient free. This prop-mode transient is weaker due to the change in sign of the pitch angle but a change in the direction of the hub rotation produces a large spike and the reasons are discussed. Fine thrust control with individual fin hydrodynamics at the source that involves the lowest change in inertia is smoother. Smooth thrust reversibility is clearly identified as a unique property of flapping fin hydrodynamics. The mechanism overlap occurs because both fin modes have similar low transitional Reynolds numbers. Dynamical system models of unsteady hydrodynamics and control are shown to be similar suggesting that animal swimmers control vortex shedding ion-by-ion and animal-like motion control is theoretically possible with the proposed propulsor in the slosh mode but not in the prop mode.
关键词： hydrodynamics,oscillating propulsor,nonlinear control,force transient,Bioinspiration
更新于2025-09-16 10:30:52
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Stochastic Resonance in Bioinspired Electronic Device Using Polymer Field Effect Transistors
摘要： Stochastic resonance (SR) phenomenon is emerged in organic field effect transistors (OFETs) using π-conjugated polymer, where application of external noise to the OFET system enhances signal/information processing performance which is often found in biological systems. The channel conductivity of the OFET is slightly increased by spin-coating using heated semiconductor polymer solution with heated glass substrate. In order to improve frequency responses of OFET, optimal width of the gate electrode is explored. Furthermore, it turns out that scratching and removing semiconductor film outside the source-drain electrodes and the channel enhances the On-Off current ratio of the device. These fabrication processes lead to steeper nonlinearity on the IDS vs. VGS curve, resulting in emergence of SR, which is fingerprinted in increase of correlation value between input and output signals with increase of intensity of external noise.
关键词： Stochastic resonance,Polymer thin films,Organic semiconductors,Bioinspiration,Field effect transistors
更新于2025-09-09 09:28:46