Simulating adhesion of wet fabrics to water: Gravity of liquid bridge-based theoretical model and experimental verification

2016 ◽  
Vol 87 (7) ◽  
pp. 769-779 ◽  
Author(s):  
Lin Lou ◽  
Jianfei Xie ◽  
Feng Ji ◽  
Yiping Qiu ◽  
Xiaohang Zhu ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Human Skin ◽  
Experimental Verification ◽  
Liquid Bridge ◽  
Adhesion Force ◽  
Body Movement ◽  
Experimental Results ◽  
Potential Solution ◽  
Adhesion Forces ◽  
Fabric Surface

Wet fabric bothers everyone as it sticks to the skin, hinders body movement and brings discomfort and awkwardness on many occasions. Much has to be done to evaluate this adhesion of a wet fabric to human skin for minimizing the discomfort resulting from this phenomenon. In this study, an improved measurement is developed to test and distinguish the adhesion forces of different materials under controlled conditions. A new and improved theoretical model is proposed to estimate the adhesion force based on the gravity of the liquid bridge that formed beneath the fabric. The theoretical values are reasonably consistent with the experimental results. A potential solution is also proposed for reducing the volume of the liquid bridge in designing a less adhesive fabric by constructing hydrophobic protrusions to the fabric surface.

scholarly journals Experimental verification of new features of bearing operation under combined loading conditions

2021 ◽  
Vol 17 (3) ◽  
pp. 278-287
Author(s):  
Valeriy V. Kirilovskiy ◽  
Yuri V. Belousov
Keyword(s):  
Theoretical Model ◽  
Experimental Verification ◽  
Traditional Method ◽  
Geometric Shape ◽  
Experimental Results ◽  
Combined Loading ◽  
Loading Conditions ◽  
Structural Elements ◽  
Elastic Line ◽  
Bearing Assembly

Bearing units of lifting machines, products of construction, road, aviation, space and other branches of technology are very important structural elements, since the failure of even one bearing can cause the failure of the entire product. The results of experimental verification of the theoretical model of bearing operation under combined loading conditions are presented. The behavior under load of bearing units in the most general case can be represented by a sequence of five design schemes, expressed in the form of five statically indeterminate beams. The purpose of the experiments was to test this model under real loading conditions. The experiments were based on the analysis of the geometric shape of the curved elastic line, which the shaft of the bearing assembly acquires under load. The experimental results confirmed the validity of the model and showed that the previously generally accepted model of a two-support beam is not implemented. The conclusion is confirmed that in responsible lifting machines, as well as in responsible products of construction, road, aviation, space and other branches of technology, it is impractical to calculate bearings according to the traditional method, since an erroneous value of bearing durability can be obtained, overestimated from 28.37 to 26.663.9 times.

Optimization of Electrostatic Adhesives for Robotic Climbing and Manipulation

2012 ◽  
Author(s):  
Donald Ruffatto ◽  
Jainam Shah ◽  
Matthew Spenko
Keyword(s):  
Electric Field ◽  
Adhesion Force ◽  
Substrate Material ◽  
Experimental Results ◽  
Adhesion Forces ◽  
Insulating Materials ◽  
Wide Range ◽  
Attachment Mechanism ◽  
Optimal Configurations ◽  
Electrostatic Adhesion

This paper investigates the optimization of electrode geometry in electrostatic adhesives to enhance adhesion forces for use in robotic climbing and gripping applications. Electrostatic adhesion provides an attachment mechanism that is both controllable and effective over a wide range of surfaces including conductive, semi-conductive, and insulating materials. The adhesives function by utilizing a set of high voltage electrodes that generate an electric field. This electric field polarizes the substrate material, thus generating an adhesion force. Optimizing the geometry of these conductive electrodes provides enhanced adhesion forces that increase attachment robustness. To accomplish this, FEA software was used to evaluate the generated electric field for a given electrode configuration. A range of electrode widths and gap sizes were evaluated to find the optimal configuration. These findings were compared with experimental results for different pad geometries over a range of surface types. Experimental results indicate that on smooth surfaces the simulation results are representative of the actual recorded adhesion forces. Rough surfaces provide similar trends but with varying optimal configurations, likely due to the level of electric field dispersion.

scholarly journals Experimental Verification of Anomalous Forces on Shielded Symmetrical Capacitors

2020 ◽  
Vol 12 (2) ◽  
pp. 33
Author(s):  
Elio B. Porcelli ◽  
Omar R. Alves ◽  
Victo S. Filho
Keyword(s):  
Theoretical Model ◽  
Quantum Entanglement ◽  
Experimental Verification ◽  
Good Accuracy ◽  
Experimental Results ◽  
Experimental Measurements ◽  
Ionic Wind ◽  
Dipole Force ◽  
Electric Potentials ◽  
Positive Results

In this work, we measured the magnitude of forces raised from the operation of symmetrical capacitor devices working in high electric potentials. Our experimental measurements were realized with basis on an improved setup which aimed significant reduction of ionic wind by means of an efficient shield. We observed small variations of the device inertia within an accurate range and we confirmed with good accuracy that the experimental results can be explained by a generalized quantum entanglement hypothesis which provides us a theoretical model for a macroscopic dipole force raised by the myriad of microscopic dipoles constituting the capacitor. The new results corroborated the positive results of previous experiments and also indicate the validity of our theoretical forecast.

Actuation and dynamic mechanical characteristics of a core free flat dielectric electro-active polymer soft actuator

2020 ◽  
Vol 14 (4) ◽  
pp. 7396-7404
Author(s):  
Abdul Malek Abdul Wahab ◽  
Emiliano Rustighi ◽  
Zainudin A.
Keyword(s):  
Theoretical Model ◽  
Resonance Frequency ◽  
Dynamic Testing ◽  
Experimental Results ◽  
Percentage Error ◽  
Initial Tension ◽  
Average Percentage ◽  
Soft Actuator ◽  
Average Percentage Error ◽  
Mechanical Dynamics

Various complex shapes of dielectric electro-active polymer (DEAP) actuator have been promoted for several types of applications. In this study, the actuation and mechanical dynamics characteristics of a new core free flat DEAP soft actuator were investigated. This actuator was developed by Danfoss PolyPower. DC voltage of up to 2000 V was supplied for identifying the actuation characteristics of the actuator and compare with the existing formula. The operational frequency of the actuator was determined by dynamic testing. Then, the soft actuator has been modelled as a uniform bar rigidly fixed at one end and attached to mass at another end. Results from the theoretical model were compared with the experimental results. It was found that the deformation of the current actuator was quadratic proportional to the voltage supplied. It was found that experimental results and theory were not in good agreement for low and high voltage with average percentage error are 104% and 20.7%, respectively. The resonance frequency of the actuator was near 14 Hz. Mass of load added, inhomogeneity and initial tension significantly affected the resonance frequency of the soft actuator. The experimental results were consistent with the theoretical model at zero load. However, due to inhomogeneity, the frequency response function’s plot underlines a poor prediction where the theoretical calculation was far from experimental results as values of load increasing with the average percentage error 15.7%. Hence, it shows the proposed analytical procedure not suitable to provide accurate natural frequency for the DEAP soft actuator.

scholarly journals Carbohydrate–carbohydrate interaction provides adhesion force and specificity for cellular recognition

2004 ◽  
Vol 165 (4) ◽  
pp. 529-537 ◽  
Author(s):  
Iwona Bucior ◽  
Simon Scheuring ◽  
Andreas Engel ◽  
Max M. Burger
Keyword(s):  
Adhesion Force ◽  
Species Specificity ◽  
Live Cells ◽  
Sponge Cell ◽  
Cell Recognition ◽  
Adhesion Forces ◽  
Cellular Recognition ◽  
Strong Adhesion ◽  
Species Specific ◽  
Cell Cell

The adhesion force and specificity in the first experimental evidence for cell–cell recognition in the animal kingdom were assigned to marine sponge cell surface proteoglycans. However, the question whether the specificity resided in a protein or carbohydrate moiety could not yet be resolved. Here, the strength and species specificity of cell–cell recognition could be assigned to a direct carbohydrate–carbohydrate interaction. Atomic force microscopy measurements revealed equally strong adhesion forces between glycan molecules (190–310 piconewtons) as between proteins in antibody–antigen interactions (244 piconewtons). Quantitative measurements of adhesion forces between glycans from identical species versus glycans from different species confirmed the species specificity of the interaction. Glycan-coated beads aggregated according to their species of origin, i.e., the same way as live sponge cells did. Live cells also demonstrated species selective binding to glycans coated on surfaces. These findings confirm for the first time the existence of relatively strong and species-specific recognition between surface glycans, a process that may have significant implications in cellular recognition.

A theoretical model of the knee and ACL: Theory and experimental verification

1992 ◽  
Vol 25 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Deb A. Loch ◽  
Zongping Luo ◽  
Jack L. Lewis ◽  
Nathaniel J. Stewart
Keyword(s):  
Theoretical Model ◽  
Experimental Verification

Adhesion Force Between High Energy Surfaces in Vapor Atmosphere

1994 ◽  
Vol 366 ◽  
Author(s):  
Jerome Crassous ◽  
Jean-Luc Loubet ◽  
Elisabeth Charlaix
Keyword(s):  
Liquid Bridge ◽  
Adhesion Force ◽  
Van Der Waals ◽  
Surface Force ◽  
High Energy ◽  
Attractive Force ◽  
Experimental Measurements ◽  
Metallic Substrates ◽  
Energy Surfaces ◽  
Good Agreement

ABSTRACTWe report experimental measurements of the adhesion force between metallic substrates in undersaturated heptane vapor atmosphere, with a surface force apparatus. The attractive force between the substrates is strongly dependant of the condensation of a liquid bridge connecting the surfaces. The results show the importance of wetting phenomena for the maximum attractive force: we find that this maximum attraction varies as the power two-third of the curvature of the meniscus connecting the surfaces, in good agreement with the theory of Van der Waals wetting.

scholarly journals Investigation of thermal conductivity of single-wall carbon nanotubes

2011 ◽  
Vol 15 (2) ◽  
pp. 565-570 ◽  
Author(s):  
Mahmoud Jafari ◽  
Majid Vaezzadeh ◽  
Momhamad Mansouri ◽  
Abazar Hajnorouzi
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Theoretical Model ◽  
Potential Energy ◽  
Experimental Results ◽  
Single Wall Carbon Nanotubes ◽  
Lattice Vibrations ◽  
Single Wall Carbon ◽  
Thermal Potential ◽  
Conductivity Behavior

In this paper, the thermal conductivity of Single-wall carbon nanotubes (SWCNTs) is determined by lattice vibrations (phonons) and free elections. The thermal conductivity of SWCNTs is modeled up to 8-300 K and the observed deviations in K-T figures of SWCNTs are explained in terms of phonon vibrations models. An suitable theoretical model is shown for thermal conductivity behavior with respect to temperature and is generalized for experimental results. This model enables us to calculate thermal conductivity SWNTs and Thermal Potential Energy (TPE).

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