Dynamic adhesive forces in rough contacting bodies including normal and sliding conditions

Yeo, Chang Dong; Lee, Jung‐Kyu; Polycarpou, Andreas A.

doi:10.1080/01694243.2012.701466

Cited by 7 publications

(3 citation statements)

References 20 publications

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“…where γ is the surface tension for a specific final radius of the droplet, R s , γ bulk and δ ∞ are the surface tension and Tolman length, respectively, for a droplet of infinite radius. Considering the radius of the tip to be 10 nm, RH 5%, and water surface tension 72 mN/m, the volume of water trapped in the meniscus is only 1.611 nm 3 , which corresponds to the radius of an equivalent water sphere, R s = 0.727 nm. Hence, upon choosing the Tolman length δ ∞ = 0.096 nm for water, 38 the surface tension of water calculated according to eq 8 is 57 mN/m.…”

Section: ■ Resultsmentioning

confidence: 99%

“…The water bridge condensed between a hydrophilic surface and tip under ambient conditions plays a very important role in measurements and applications provided by atomic force microscopes (AFMs) nowadays . The presence of water can significantly affect the adhesive and frictional force interaction between the tip and the surface. − Furthermore, the bridge size directly determines the dimensions of nanostructures fabricated by dip-pen nanolithography , or local anodic oxidation − and introduces one of the limitations of their resolution. Because of these reasons, the information about the amount of water condensed under the tip has a significant consequence for interpretation of force magnitudes in measurements and progress in resolution of AFM-based nanolithography techniques.…”

Section: Introductionmentioning

confidence: 99%

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Nanometer-Sized Water Bridge and Pull-Off Force in AFM at Different Relative Humidities: Reproducibility Measurement and Model Based on Surface Tension Change

et al. 2017

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This article deals with the analysis of the relationship between the pull-off force measured by atomic force microscopy and the dimensions of water bridge condensed between a hydrophilic silicon oxide tip and a silicon oxide surface under ambient conditions. Our experiments have shown that the pull-off force increases linearly with the radius of the tip and nonmonotonically with the relative humidity (RH). The latter dependence generally consists of an initial constant part changing to a convex-concave-like increase of the pull-off force and finally followed by a concave-like decrease of this force. The reproducibility tests have demonstrated that the precision limits have to be taken into account for comparing these measurements carried out under atmospheric conditions. The results were fitted by a classical thermodynamic model based on water-bridge envelope calculations using the numerical solution of the Kelvin equation in the form of axisymmetric differential equations and consequent calculation of adhesive forces. To describe the measured data more precisely, a decrease of the water surface tension for low RH was incorporated into the calculation. Such a decrease can be expected as a consequence of the high surface curvature in the nanometer-sized water bridge between the tip and the surface.

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Section: ■ Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Nanometer-Sized Water Bridge and Pull-Off Force in AFM at Different Relative Humidities: Reproducibility Measurement and Model Based on Surface Tension Change

et al. 2017

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“…In 2017, Lindsay Vasilak used strain gauge load cell to measure the normal adhesive force of OLED [14]. Chang-Dong Yeo used a high-resolution, high-dynamic bandwidth capacitive force transducer and two piezoelectric actuators to measure adhesive pull-off forces between nominally flat rough silicon surfaces under various dynamic conditions [15]. Jaeho Lee used Atomic Force Microscope (AFM) to measure the adhesion between the colloidal probe and silicon wafer.…”

Section: Introductionmentioning

confidence: 99%

The Adhesive Force Measurement between Single μLED and Substrate Based on Atomic Force Microscope

et al. 2022

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Compared with traditional liquid crystal and organic light emitting diode (OLED), micro light emitting diode (μLED) has advantages in brightness, power consumption, and response speed. It has important applications in microelectronics, micro-electro-mechanical systems, biomedicine, and sensor systems. μLED massive transfer method plays an important role in these applications. However, the existing μLED massive transfer method is faced with the problem of low yield. To better transfer the μLED, the force value detached from the substrate needs to be measured. Atomic force microscope (AFM) was used to measure the force of a single μLED when it detached from the substrate. The μLED was glued to the front of the cantilever. When a single μLED was in contact with or detached from the Polydimethylsiloxane (PDMS), the maximum pull-off force can be obtained. The force at different peel speeds and preload was measured, and the experimental results show that the separation force between a single μLED and PDMS substrate is not only related to the peel speeds, but also related to the preload. The force values under different peel speeds and preload were measured to lay a theoretical foundation for better design of μLED massive transfer system.

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Reversible Bonding of Aromatic Thermosetting Copolyesters for In‐Space Assembly

Meyer

Bakır

Lan

et al. 2019

Macro Materials & Eng

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usually divided into two main categories. One category is to use a micro-patterned surface that mimics the bio-structures and the other category is to solely apply nonpatterned adhesive polymers. The adhesion force between different surfaces is generated due to van der Waals forces, [7] capillary forces, [8] mechanical interlocking, [9] covalent bond, [10] and hydrogen bonding. [11] The patterned surfaces can have higher compliance and conformability to various substrate topographies, thus may exhibit better adhesion, compared to non-patterned counterparts. [12] Table 1 summarizes several studies reported in the literature that investigated reversible adhesion or reversible bonding mechanisms, including both patterned and non-patterned methods. The bonding parameters, measured bonding strength, and numbers of bond/debond cycles are listed in the table. Regardless of adhesive media and bonding conditions, the maximum pull-off strength (or bonding strength) is 10 MPa, corresponding to three cycles, and the maximum repeated cycle number is 60, corresponding to 0.53 MPa lap shear strength.The NASA 2015 technology roadmap TA12 [13] proposes lightweight joining concepts by eliminating bolted joints and the NASA 2017 SBIR solicitation [14] describes the ability to reversibly join structural truss units capable of sustaining loads of 100-500 N. In this work, we show a non-patterned reversible bonding solution which shows a combined bonding strength far over 10 MPa, and over 50 bond/debond cycles at both ambient and elevated temperatures, which is potentially of utility for applications such as in the automotive and aerospace industries. To be viable for in-space assembly, adhesive performance at elevated temperatures is a requirement for bonds exposed to the high temperatures that surfaces outside of Earth's atmosphere cyclically sustain when exposed to the Sun. Generally, the schemes described in Table 1 are characterized in terms of bonding strength at room temperature and use polymers that have glass transitions lower than typical values experienced in daylight in Earth orbit.Aromatic thermosetting copolyester (ATSP) is a cured product of cross-linkable aromatic polyester oligomers of various branch coefficients and molecular weight Aromatic Thermosetting CopolymersReversible bonding is an attractive option for assembly and disassembly of reconfigurable space structures due to the simplicity of the fastening concept. Interchain transesterifications reaction [ITR-a type of dynamic covalent exchange reactions afforded by aromatic thermosetting copolyesters (ATSP)] between two ATSP coatings can successfully be used as a reversible bonding concept, provided that the mode of debonding is completely cohesive (rather than adhesive or delaminatory from metal substrate). An optimization study is carried out on the ITR bonding for which ATSP coating is applied on 7075 aluminum substrates and bond/debond experiments are carried out using a custom-built tool kit. The toolkit enables precise control over bonding pressure, tempe...

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Dynamic adhesive forces in rough contacting bodies including normal and sliding conditions

Cited by 7 publications

References 20 publications

Nanometer-Sized Water Bridge and Pull-Off Force in AFM at Different Relative Humidities: Reproducibility Measurement and Model Based on Surface Tension Change

Nanometer-Sized Water Bridge and Pull-Off Force in AFM at Different Relative Humidities: Reproducibility Measurement and Model Based on Surface Tension Change

The Adhesive Force Measurement between Single μLED and Substrate Based on Atomic Force Microscope

Reversible Bonding of Aromatic Thermosetting Copolyesters for In‐Space Assembly

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