Tunable adhesion of an elastic pillar by pressurizing inner cavity

2021 ◽  
pp. 135065012110182
Author(s):  
Turgay Eray
Keyword(s):  
Adhesion Strength ◽  
Smooth Surface ◽  
Adhesive Contact ◽  
Adhesive Force ◽  
Membrane Thickness ◽  
Cavity Pressure ◽  
Flat Punch ◽  
Contact Type ◽  
Inner Pressure ◽  
Rigid Smooth

This work studies the effect of a cavity with inner pressure on the adhesion of circular pillars with a flat tip in contact with a rigid smooth surface. The inner cavity of pillars is pressurized positively before the contact. The effect of the cavity on the adhesion is examined for different cavity diameters and different membrane thicknesses over the cavity. The shape of the tip of the pillars is changed in accordance with the cavity dimension and the positive cavity pressure, which allows the change of an adhesive contact type from a flat-punch adhesive contact to a spherical adhesive contact that results in tunable adhesion strength of circular pillars. The results demonstrate that having an inner cavity reduces the adhesion, where the cavity diameter is more effective than the membrane thickness over the cavity on the reduction of the adhesive force. Applying pressure to the inner cavity of the pillars changes the sphericity, which alters the adhesive force accordingly. The sphericity 0.1 almost has no effect on the tunable adhesion strength, where the higher sphericity results in the reduction of the adhesive force from high adhesive force to low adhesive force linearly with a tunable efficiency between 95% and 98%.

scholarly journals Air mediates the impact of a compliant hemisphere on a rigid smooth surface

Soft Matter ◽  
2021 ◽  
Author(s):  
Siqi Zheng ◽  
Sam Dillavou ◽  
John M. Kolinski
Keyword(s):  
Elastic Body ◽  
Elastic Properties ◽  
Impact Velocity ◽  
Solid Surface ◽  
High Speed ◽  
Smooth Surface ◽  
High Speed Imaging ◽  
The Impact ◽  
Rigid Smooth

When a soft elastic body impacts upon a smooth solid surface, the intervening air fails to drain, deforming the impactor. High-speed imaging with the VFT reveal rich dynamics and sensitivity to the impactor's elastic properties and the impact velocity.

Adhesive Force of a Spider Mite, Tetranychus urticae, to a Flat Smooth Surface

2006 ◽  
Vol 49 (2) ◽  
pp. 539-544 ◽  
Author(s):  
Katsumi MIZUTANI ◽  
Kai EGASHIRA ◽  
Tadashi TOUKAI ◽  
Jun OGUSHI
Keyword(s):  
Tetranychus Urticae ◽  
Smooth Surface ◽  
Spider Mite ◽  
Adhesive Force

scholarly journals Adhesion of Soft Materials to Rough Surfaces: Experimental Studies, Statistical Analysis and Modelling

Coatings ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 350 ◽  
Author(s):  
Andrey Pepelyshev ◽  
Feodor Borodich ◽  
Boris Galanov ◽  
Elena Gorb ◽  
Stanislav Gorb
Keyword(s):  
Statistical Analysis ◽  
Smooth Surface ◽  
Rough Surfaces ◽  
Experimental Studies ◽  
Soft Materials ◽  
Adhesive Contact ◽  
Theoretical Modelling ◽  
Height Distribution ◽  
Depth Sensing ◽  
Adhesive Properties

Adhesion between rough surfaces is an active field of research where both experimental studies and theoretical modelling are used. However, it is rather difficult to conduct precise experimental evaluations of adhesive properties of the so-called anti-adhesive materials. Hence, it was suggested earlier by Purtov et al. (2013) to prepare epoxy resin replicas of surfaces having different topography and conduct depth-sensing indentation of the samples using a micro-force tester with a spherical smooth probe made of the compliant polydimethylsiloxane polymer in order to compare values of the force of adhesion to the surfaces. Surprising experimental observations were obtained in which a surface having very small roughness showed the greater value of the force of adhesion than the value for a replica of smooth surface. A plausible explanation of the data was given suggesting that these rough surfaces had full adhesive contact and their true contact area is greater than the area for a smooth surface, while the surfaces with higher values of roughness do not have full contact. Here, the experimental results of surface topography measurements and the statistical analysis of the data are presented. Several modern tests of normality used showed that the height distribution of the surfaces under investigation is normal (Gaussian) and hence the classic statistical models of adhesive contact between rough surfaces may formally be used. Employing one of the Galanov (2011) models of adhesive contact between rough surfaces, the plausible explanation of the experimental observations has been confirmed and theoretically justified.

Numerical Method of Analyzing Contact Mechanics between a Sphere and a Flat Considering Lennard-Jones Surface Forces of Contacting Asperities and Noncontacting Rough Surfaces

2012 ◽  
Vol 134 (1) ◽  
Author(s):  
Kyosuke Ono
Keyword(s):  
Numerical Method ◽  
Contact Mechanics ◽  
Rough Surfaces ◽  
Present Theory ◽  
Adhesive Contact ◽  
Adhesive Force ◽  
Surface Forces ◽  
Contact Theory ◽  
Magnetic Disk ◽  
Lennard Jones

A new numerical method of analyzing adhesive contact mechanics between a sphere and a flat with sub-nanometer roughness is presented. In contrast to conventional theories, the elastic deformations of mean height surfaces and contacting asperities, and Lennard-Jones (LJ) surface forces of both the contacting asperities and noncontacting rough surfaces including valley areas are taken into account. Calculated contact characteristics of a 2-mm-radius glass slider contacting a magnetic disk with a relatively rough surface and a 30-mm-radius head slider contacting a currently available magnetic disk with lower roughness are shown in comparison with conventional adhesive contact theories. The present theory was found to give a larger adhesive force than the conventional theories and to converge to a smooth sphere-flat contact theory as the roughness height approaches zero.

scholarly journals Adhesive Force of a Spider Mite, Tetranychus urticae, to a Flat Smooth Surface

2005 ◽  
Vol 71 (706) ◽  
pp. 2094-2099 ◽  
Author(s):  
Katsumi MIZUTANI ◽  
Kai EGASHIRA ◽  
Tadashi TOUKAI ◽  
Jun OGUSHI
Keyword(s):  
Tetranychus Urticae ◽  
Smooth Surface ◽  
Spider Mite ◽  
Adhesive Force

scholarly journals Strength statistics of adhesive contact between a fibrillar structure and a rough substrate

2007 ◽  
Vol 5 (21) ◽  
pp. 441-448 ◽  
Author(s):  
Pankaj K Porwal ◽  
Chung Yuen Hui
Keyword(s):  
Adhesion Strength ◽  
Probability Distributions ◽  
Adhesive Contact ◽  
Strength Distribution ◽  
Fibrillar Structure ◽  
Substrate Roughness ◽  
Equal Distribution ◽  
Fibril Structure ◽  
Attachment Strength ◽  
Fibril Length

Equal distribution of load among fibrils in contact with a substrate is an important characteristic of fibrillar structures used by many small animals and insects for contact and adhesion. This is in contrast with continuum systems where stress concentration dominates interfacial failure. In this work, we study how adhesion strength of a fibrillar system depends on substrate roughness and variability of the fibril structure, which are modelled using probability distributions for fibril length and fibril attachment strength. Monte Carlo simulations are carried out to determine the adhesion strength statistics where fibril length follows normal or uniform distribution and attachment strength has a power-law form. Our results indicate that the strength distribution is Gaussian (normal) for both the uniform and the normal distributions for length. However, the fibrillar structure having normally distributed lengths has higher strength and lower toughness than one having uniformly distributed lengths. Our simulations also show that an increase in the compliance of the fibrils can compensate for both the substrate roughness and the attachment strength variation. We also show that, as the number of fibrils n increases, the load-carrying efficiency of each fibril goes down. For large n , this effect is found to be small. Furthermore, this effect is compensated by the fact that the standard deviation of the adhesive strength decreases as .

Adhesive Contact Modeling of Ultra-Low Flying Head-Disk Interfaces With and Without Roughness Effects

2005 ◽  
Author(s):  
A. Y. Suh ◽  
A. A. Polycarpou
Keyword(s):  
Adhesive Contact ◽  
Adhesive Force ◽  
Flying Height ◽  
Successful Implementation ◽  
Roughness Effects ◽  
Interfacial Forces ◽  
Disk Interface ◽  
Parallel Surface ◽  
Effect Of Surface ◽  
Adhesive Forces

The head-disk interface (HDI) designed for sub-5nm pseudo-flying to obtain extremely high areal recording (EHDR) density of 1 Tbit/in is susceptible to strong adhesive interfacial forces, and the accurate predictions of these interfacial forces are critical in ensuring successful implementation of ultra-low flying HDI’s. In this paper, the effect of surface roughness on the adhesive forces at sub-5 nm flying-height regimes is investigated through a comparison to a simple two flat parallel surface counterpart. It was found that the effect of roughness promotes adhesion at higher separations than if a two flat parallel surface configuration is adopted. Prior to the onset of contact (during flying), however, the total adhesive force for an interface with low roughness is comparable to the two flat parallel surface approximation, thus significantly simplifying the analysis.

scholarly journals Adhesive strength in a high voltage mica insulation system

2019 ◽  
Vol 140 ◽  
pp. 11006
Author(s):  
Tatiana Shikova
Keyword(s):  
Adhesion Strength ◽  
High Voltage ◽  
Adhesive Strength ◽  
Adhesive Contact ◽  
Test Method ◽  
Technological Parameters ◽  
Contact Materials ◽  
Pressing Process ◽  
Thermal Pressing ◽  
Degree Of Curing

The problem of maintaining a monolithic high-voltage mica insulation made by the Resin Rich technology for windings of electrical machines and conductors is considered. The violation of solidity like delaminations and peeling off from conductor can happen both during the process of manufacturing and during exploitation of constructions. The possibility of breaking the solidity is directly related to the magnitude of adhesion strength. Design and manufacturing technology of samples in laboratory and industrial conditions to determine the adhesion strength were developed. Adhesive strength is determined by the method of shear and tensile test method between insulation layers and in system of metal- mica insulation.The created method for the manufacture of samples made it possible to test samples with various designs of adhesive contact, materials of adhesive contact and technological parameters of the pressing process. The adhesion strength depends on the parameters of the thermal pressing process and the degree of curing of the binder in the initial resin rich tape. Adhesive contact of mica insulation to metal through fiberglass is more durable than through film

A novel and reliable approach for controlling silicon membrane thickness with smooth surface

2022 ◽  
Vol 251 ◽  
pp. 111640
Author(s):  
Yijie Li ◽  
Yifang Chen ◽  
Hongchang Wang ◽  
Xujie Tong ◽  
Chengyang Mu ◽  
...  
Keyword(s):  
Smooth Surface ◽  
Membrane Thickness ◽  
Silicon Membrane
Sign in / Sign up

Export Citation Format

Share Document