Atomic force microscope adhesion measurements and atomistic molecular dynamics simulations at different humidities

Seppä, Jeremias; Reischl, Bernhard; Sairanen, Hannu; Korpelainen, Virpi; Husu, Hannu; Heinonen, Martti; Raiteri, Paolo; Rohl, Andrew L.; Nordlund, K.; Lassila, Antti

doi:10.1088/1361-6501/28/3/034004

Cited by 7 publications

(4 citation statements)

References 41 publications

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“…[ 41 ] The Si substrate was modelled as a SiO 2 slab fully covered by silanol groups (Si‐OH) because a thin oxidized layer was formed on the Si substrate due to the oxidization of Si in humid air, as shown in Figure 8b. [ 42 ] The interface between the mica and the SiO 2 slabs was filled with a water layer, in which water molecules interact with the bottom surface (0001) of the mica slab and the top surface of SiO 2 (001) slab, as shown in Figure 8c. The INTERFACE force fields for the mica‐water, water‐SiO 2 and mica‐SiO 2 interactions were used in the MD simulation.…”

Section: Experiments and Simulationmentioning

confidence: 99%

The Adhesion of Mica Nanolayers on a Silicon Substrate in Air

Wang

et al. 2020

Adv Materials Inter

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properties render MNLs as a nearly perfect dielectric material that is expected to considerably improve the electron transport properties of Si based microelectronic devices. Previous studies demonstrated that the use of a MNL as the dielectric layer onto a Si substrate doubled the carrier mobility of graphene field effect transistors (FETs) and increased their transconductance several fold. [3] It also improves the gate control capability of carbon nanotubes (CNTs) FETs by suppressing gate leakage current and decreasing subthreshold slope. [4] In particular, MNLs can replace polymers as dielectric media in flexible electronics. [5,6] Compared with polymer insulators, MNLs not only improve the electron transport properties (because of their higher dielectric constant), but also reduce the effect of elastic mismatch because mica and Si have similar mechanical properties. [7] These make MNLs potentially excellent candidates for Si based flexible devices as dielectric components. In most electronic devices, an MNL is mechanically bonded onto a Si substrate. Thus, the adhesion between the MNL and Si substrate determines the reliability and life of the electronic devices. [8] This is especially important for flexible electronic devices with MNLs that frequently experience bending, twisting and stretching. [9] Characterization of the adhesion of MNLs on a flat substrate is challenging. Previous studies often used the atomic force microscopes (AFM) to measure the adhesion. [10] AFM directly measures the adhesive force of a target material with the AFM tip, rather than the adhesion energy that characterizes the adhesion. To evaluate the adhesion energy of graphene on a flat substrate, a blister method was used. [11] However, the sample preparation in the blister method is relatively long, which is not applicable for MNLs because they can be heavily contaminated during a lengthy preparation process. In situ scanning electron microscope (SEM) peeling is a possible alternative, but electron beam irradiation could considerably affect the surface status of MNL samples. [12,13] The peeling method is also inconvenient for characterising the effect of environmental conditions, such as temperature and humidity, on the adhesion that is the important knowledge for MNL based sensor design and development. [14] In our previous work, [15] a bridging method was developed based on nanomanipulation under an optical microscope, with Mica nanolayers (MNL) are a new dielectric material that can improve the electron transport properties of Si based microelectronic devices. However, the mechanical reliability of such devices is not well understood because measurement of the adhesion between an MNL and a Si substrate is insufficiently accurate. The recent work reports a bridging method that is developed based on the linear beam theory and can characterize the adhesion of MNL on a mica substrate in a reasonably accuracy. In this work, the accuracy of the bridging method is improved by using a nonlinear mechanical model. 15 MNL specimens are mea...

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Section: Experiments and Simulationmentioning

confidence: 99%

The Adhesion of Mica Nanolayers on a Silicon Substrate in Air

Wang

et al. 2020

Adv Materials Inter

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“…Furthermore, depending on the method of nanorod deposition, surfactant molecules (which keep the nanorods from agglomerating in solution) could still be attached to their surfaces. Finally, if the experiment is carried out in ambient conditions, all surfaces are covered in a thin film of water, the thickness of which depends on the relative humidity 43 , and a meniscus would form when the tip approached the sample 44 – 46 . Depending on the details of the interface region, water molecules could remain trapped between the tip and sample during indentation.…”

Section: Resultsmentioning

confidence: 99%

Atomistic simulation of the measurement of mechanical properties of gold nanorods by AFM

Reischl

Rohl

Kuronen

et al. 2017

Sci Rep

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Mechanical properties of nanoscale objects can be measured with an atomic force microscope (AFM) tip. However, the continuum models typically used to relate the force measured at a certain indentation depth to quantities such as the elastic modulus, may not be valid at such small scales, where the details of atomistic processes need to be taken into account. On the other hand, molecular dynamics (MD) simulations of nanoindentation, which can offer understanding at an atomistic level, are often performed on systems much smaller than the ones studied experimentally. Here, we present large scale MD simulations of the nanoindentation of single crystal and penta-twinned gold nanorod samples on a silicon substrate, with a spherical diamond AFM tip apex. Both the sample and tip sizes and geometries match commercially available products, potentially linking simulation and experiment. Different deformation mechanisms, involving the creation, migration and annihilation of dislocations are observed depending on the nanorod crystallographic structure and orientation. Using the Oliver-Pharr method, the Young’s moduli of the (100) terminated and (110) terminated single crystal nanorods, and the penta-twinned nanorod, have been determined to be 103 ± 2, 140 ± 4 and 108 ± 2 GPa, respectively, which is in good agreement with bending experiments performed on nanowires.

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“…A more appropriate effort would be to perform MD simulation of the cutting process in the presence of water molecules (see Figure 12). The interatomic potential function now exists for doing such studies [49,50].…”

Section: Simulation Application In Advance Subtractive Manufacturing Processesmentioning

confidence: 99%

Horizons of modern molecular dynamics simulation in digitalized solid freeform fabrication with advanced materials

Goel

Knaggs

Goel

et al. 2020

Materials Today Chemistry

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Our ability to shape and finish a component by combined methods of fabrication including (but not limited to) subtractive, additive and/or no theoretical mass-loss/addition during the fabrication is now popularly known as solid freeform fabrication. Fabrication of a telescope mirror is a typical example where grinding and polishing processes are first applied to shape the mirror and thereafter an optical coating is usually applied to enhance its optical performance. The area of nanomanufacturing cannot grow without a deep knowledge of the fundamentals of materials and consequently, the use of computer simulations is becoming ubiquitous. This article is intended to introduce the most recent advances in the computation benefit specific to the area of solid freeform fabrication as these systems are traversing through the journey of digitalisation and Industry-4.0. Specifically, this article demonstrates that the application of the latest materials modelling approaches, based on techniques such as molecular Just accepted in Materials Today Chemistry 2 dynamics, are enabling breakthroughs in applied precision manufacturing techniques.

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Atomic force microscope adhesion measurements and atomistic molecular dynamics simulations at different humidities

Cited by 7 publications

References 41 publications

The Adhesion of Mica Nanolayers on a Silicon Substrate in Air

The Adhesion of Mica Nanolayers on a Silicon Substrate in Air

Atomistic simulation of the measurement of mechanical properties of gold nanorods by AFM

Horizons of modern molecular dynamics simulation in digitalized solid freeform fabrication with advanced materials

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