Theoretical and Experimental Analysis of Surface Roughness and Adhesion Forces of MEMS Surfaces Using a Novel Method for Making a Compound Sputtering Target

Achieving a compound thin film with uniform thickness and high purity has always been a challenge in the applications concerning micro electro mechanical systems (MEMS). Controlling the adhesion force in micro/nanoscale is also critical. In the present study, a novel method for making a sputtering compound target is proposed for coating Ag–Au thin films with thicknesses of 120 and 500 nm on silicon substrates. The surface topography and adhesion forces of the samples were obtained using atomic force microscope (AFM). Rabinovich and Rumpf models were utilized to measure the adhesion force and compare the results with the obtained experimental values. It was found that the layer with a thickness of 500 nm has a lower adhesion force than the one with 120 nm thickness. The results further indicated that due to surface asperity radius, the adhesion achieved from the Rabinovich model was closer to the experimental values. This novel method for making a compound sputtering target has led to a lower adhesion force which can be useful for coating microgripper surfaces.

Download Full-text

Adhesion force mapping on wood by atomic force microscopy: influence of surface roughness and tip geometry

Royal Society Open Science ◽

10.1098/rsos.160248 ◽

2016 ◽

Vol 3 (10) ◽

pp. 160248 ◽

Cited By ~ 14

Author(s):

X. Jin ◽

B. Kasal

Keyword(s):

Surface Roughness ◽

Atomic Force Microscopy ◽

Wood Surface ◽

Adhesion Force ◽

Data Interpretation ◽

Natural Fibre ◽

Force Distribution ◽

Adhesion Forces ◽

Force Microscopy ◽

Atomic Force

This study attempts to address the interpretation of atomic force microscopy (AFM) adhesion force measurements conducted on the heterogeneous rough surface of wood and natural fibre materials. The influences of wood surface roughness, tip geometry and wear on the adhesion force distribution are examined by cyclic measurements conducted on wood surface under dry inert conditions. It was found that both the variation of tip and surface roughness of wood can widen the distribution of adhesion forces, which are essential for data interpretation. When a common Si AFM tip with nanometre size is used, the influence of tip wear can be significant. Therefore, control experiments should take the sequence of measurements into consideration, e.g. repeated experiments with used tip. In comparison, colloidal tips provide highly reproducible results. Similar average values but different distributions are shown for the adhesion measured on two major components of wood surface (cell wall and lumen). Evidence supports the hypothesis that the difference of the adhesion force distribution on these two locations was mainly induced by their surface roughness.

Download Full-text

Nanoscale mapping of dielectric properties based on surface adhesion force measurements

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.9.84 ◽

2018 ◽

Vol 9 ◽

pp. 900-906 ◽

Cited By ~ 1

Author(s):

Ying Wang ◽

Yue Shen ◽

Xingya Wang ◽

Zhiwei Shen ◽

Bin Li ◽

...

Keyword(s):

Graphene Oxide ◽

Dielectric Properties ◽

Adhesion Force ◽

Model Systems ◽

Adhesion Forces ◽

Surface Adhesion ◽

Storage Devices ◽

Force Microscopy ◽

Atomic Force

The detection of local dielectric properties is of great importance in a wide variety of scientific studies and applications. Here, we report a novel method for the characterization of local dielectric distributions based on surface adhesion mapping by atomic force microscopy (AFM). The two-dimensional (2D) materials graphene oxide (GO), and partially reduced graphene oxide (RGO), which have similar thicknesses but large differences in their dielectric properties, were studied as model systems. Through direct imaging of the samples with a biased AFM tip in PeakForce Quantitative Nano-Mechanics (PF-QNM) mode, the local dielectric properties of GO and RGO were revealed by mapping their surface adhesion forces. Thus, GO and RGO could be conveniently differentiated. This method provides a simple and general approach for the fast characterization of the local dielectric properties of graphene-based materials and will further facilitate their applications in energy generation and storage devices.

Download Full-text

Comparative Analysis of Attachment to Chalcopyrite of Three Mesophilic Iron and/or Sulfur-Oxidizing Acidophiles

Minerals ◽

10.3390/min8090406 ◽

2018 ◽

Vol 8 (9) ◽

pp. 406 ◽

Cited By ~ 8

Author(s):

Qian Li ◽

Baojun Yang ◽

Jianyu Zhu ◽

Hao Jiang ◽

Jiaokun Li ◽

...

Keyword(s):

Adhesion Force ◽

Bacterial Attachment ◽

Copper Recovery ◽

Metal Sulfides ◽

Acidithiobacillus Thiooxidans ◽

Adhesion Forces ◽

Force Microscopy ◽

Atomic Force ◽

Initial Adhesion ◽

Sulfur Oxidizing

Adhesion plays an important role in bacterial dissolution of metal sulfides, since the attached cells initiate the dissolution. In addition, biofilms, forming after bacterial attachment, enhance the dissolution. In this study, interactions between initial adhesion force, attachment behavior and copper recovery were comparatively analyzed for Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, and Leptospirillum ferrooxidans during bioleaching of chalcopyrite. The adhesion forces between bacteria and minerals were measured by atomic force microscopy (AFM). L. ferrooxidans had the largest adhesion force and attached best to chalcopyrite, while A. ferrooxidans exhibited the highest bioleaching of chalcopyrite. The results suggest that the biofilm formation, rather than the initial adhesion, is positively correlated with bioleaching efficiency.

Download Full-text

Direct Measurement of Adhesion Force of Individual Aerosol Particles by Atomic Force Microscopy

Atmosphere ◽

10.3390/atmos11050489 ◽

2020 ◽

Vol 11 (5) ◽

pp. 489

Author(s):

Kohei Ono ◽

Yuki Mizushima ◽

Masaki Furuya ◽

Ryota Kunihisa ◽

Nozomu Tsuchiya ◽

...

Keyword(s):

Atomic Force Microscopy ◽

Adhesion Force ◽

Aerosol Particles ◽

Sea Salt ◽

Dust Particles ◽

Adhesion Forces ◽

Distance Curve ◽

Ambient Particles ◽

Force Microscopy ◽

Atomic Force

A new method, namely, force–distance curve mapping, was developed to directly measure the adhesion force of individual aerosol particles by atomic force microscopy. The proposed method collects adhesion force from multiple points on a single particle. It also takes into account the spatial distribution of the adhesion force affected by topography (e.g., the variation in the tip angle relative to the surface, as well as the force imposed upon contact), thereby enabling the direct and quantitative measurement of the adhesion force representing each particle. The topographic effect was first evaluated by measuring Polystyrene latex (PSL) standard particles, and the optimized method was then applied on atmospherically relevant model dust particles (quartz, ATD, and CJ-1) and inorganic particles (ammonium sulfate and artificial sea salt) to inter-compare the adhesion forces among different aerosol types. The method was further applied on the actual ambient aerosol particles collected on the western coast of Japan, when the region was under the influence of Asian dust plume. The ambient particles were classified into sea salt (SS), silicate dust, and Ca-rich dust particles based on individual particle analysis (micro-Raman or Scanning Electron Microscope/Energy Dispersive X-ray Spectroscopy (SEM-EDX)). Comparable adhesion forces were obtained from the model and ambient particles for both SS and silicate dust. Although dust particles tended to show smaller adhesion forces, the adhesion force of Ca-rich dust particles was larger than the majority of silicate dust particles and was comparable with the inorganic salt particles. These results highlight that the original chemical composition, as well as the aging process in the atmosphere, can create significant variation in the adhesion force among individual particles. This study demonstrates that force–distance curve mapping can be used as a new tool to quantitatively characterize the physical properties of aerosol particles on an individual basis.

Download Full-text

Influence of Surface Properties on Adhesion Forces and Attachment ofStreptococcus mutansto ZirconiaIn Vitro

BioMed Research International ◽

10.1155/2016/8901253 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 10

Author(s):

Pei Yu ◽

Chuanyong Wang ◽

Jinglin Zhou ◽

Li Jiang ◽

Jing Xue ◽

...

Keyword(s):

Surface Roughness ◽

Surface Properties ◽

Biofilm Formation ◽

Adhesion Force ◽

Contact Angles ◽

Adhesion Forces ◽

Force Microscopy ◽

Early Attachment ◽

Atomic Force ◽

Initial Adhesion

Zirconia is becoming a prevalent material in dentistry. However, any foreign bodies inserted may provide new niches for the bacteria in oral cavity. The object of this study was to explore the effect of surface properties including surface roughness and hydrophobicity on the adhesion and biofilm formation ofStreptococcus mutans(S. mutans) to zirconia. Atomic force microscopy was employed to determine the zirconia surface morphology and the adhesion forces between theS. mutansand zirconia. The results showed that the surface roughness was nanoscale and significantly different among tested groups (P<0.05): Coarse (23.94±2.52 nm) > Medium (17.00±3.81 nm) > Fine (11.89±1.68 nm). The contact angles of the Coarse group were the highest, followed by the Medium and the Fine groups. Increasing the surface roughness and hydrophobicity resulted in an increase of adhesion forces and early attachment (2 h and 4 h) ofS. mutanson the zirconia but no influence on the further development of biofilm (6 h~24 h). Our findings suggest that the surface roughness in nanoscale and hydrophobicity of zirconia had influence on theS. mutansinitial adhesion force and early attachment instead of whole stages of biofilm formation.

Download Full-text

Surface Forces between Nanomagnetite and Silica in Aqueous Ca2+ Solutions Studied with AFM Colloidal Probe Method

Colloids and Interfaces ◽

10.3390/colloids4030041 ◽

2020 ◽

Vol 4 (3) ◽

pp. 41

Author(s):

Illia Dobryden ◽

Elizaveta Mensi ◽

Allan Holmgren ◽

Nils Almqvist

Keyword(s):

Iron Ore ◽

Adhesion Force ◽

Surface Forces ◽

Adhesion Forces ◽

Interaction Forces ◽

Colloidal Probe ◽

Force Microscopy ◽

Atomic Force ◽

Repulsive Forces ◽

Qualitative Changes

Dispersion and aggregation of nanomagnetite (Fe3O4) and silica (SiO2) particles are of high importance in various applications, such as biomedicine, nanoelectronics, drug delivery, flotation, and pelletization of iron ore. In directly probing nanomagnetite–silica interaction, atomic force microscopy (AFM) using the colloidal probe technique has proven to be a suitable tool. In this work, the interaction between nanomagnetite and silica particles was measured with AFM in aqueous Ca2+ solution at different pH levels. This study showed that the qualitative changes of the interaction forces with pH and Ca2+ concentrations were consistent with the results from zeta-potential measurements. The repulsion between nanomagnetite and silica was observed at alkaline pH and 1 mM Ca2+ concentration, but no repulsive forces were observed at 3 mM Ca2+ concentration. The interaction forces on approach were due to van der Waals and electrical double-layer forces. The good fitting of experimental data to the DLVO model and simulations supported this conclusion. However, contributions from non-DLVO forces should also be considered. It was shown that an increase of Ca2+ concentration from 1 to 3.3 mM led to a less pronounced decrease of adhesion force with increasing pH. A comparison of measured and calculated adhesion forces with a few contact mechanics models demonstrated an important impact of nanomagnetite layer nanoroughness.

Download Full-text

Influence of Lateral Movement on Level Behavior of Adhesion Force Measured Repeatedly by an Atomic Force Microscope (AFM) Colloid Probe in Dry Conditions

Materials ◽

10.3390/ma14020370 ◽

2021 ◽

Vol 14 (2) ◽

pp. 370

Author(s):

Ping Li ◽

Tianmao Lai

Keyword(s):

Atomic Force Microscope ◽

Adhesion Force ◽

Lateral Movement ◽

Adhesion Forces ◽

Lateral Velocity ◽

Atomic Force ◽

Dry Conditions ◽

Data Points ◽

Scanning Path ◽

Material Wear

An atomic force microscope (AFM) was operated to repeatedly measure the adhesion forces between a polystyrene colloid probe and a gold film, with and without lateral movement in dry conditions. Experimental results show that the adhesion force shows a level behavior without lateral movement and with a small scan distance: the data points are grouped into several levels, and the adhesion force jumps between different levels frequently. This was attributed to the fact that when the cantilever pulls off the sample, the contact area of the sample is not exactly the same between successive contacts and jumps randomly from one to another. Both lateral velocity and material wear have little influence on level behavior. However, with a medium scan distance, level behavior is observed only for some measurements, and adhesion forces are randomly distributed for the other measurements. With a large scan distance, adhesion forces are randomly distributed for all measurements. This was attributed to the fact that the cantilever pulls off the sample in many different contact areas on the scanning path for large distances. These results may help understand the influence of lateral movement and imply the contribution of asperities to adhesion force.

Download Full-text

Quantifying the Work of Adhesion Between an AFM Cantilever Tip and MEMS Test Structures After Packaging

ISTFA 2004: Conference Proceedings from the 30th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2004p0216 ◽

2004 ◽

Author(s):

E. J. Thoreson ◽

N. A. Burnham ◽

J. Martin

Keyword(s):

Adhesion Force ◽

Mechanical Systems ◽

Work Of Adhesion ◽

Native Oxide ◽

Micro Electro Mechanical Systems ◽

Atomic Force ◽

Die Attach ◽

Silicon Cantilever ◽

Afm Cantilever ◽

And Performance

Abstract Adhesion is important to the yield and performance of MEMS (Micro-Electro-Mechanical Systems) and NEMS (Nano- Electro-Mechanical Systems). Measuring the work of adhesion, with an AFM (Atomic-Force Microscope), allows one to study surface interactions from an energy perspective as opposed to an adhesion (force) perspective. The works of adhesion were measured with different AFM tip radii on multiple types of samples. Two sample variables were examined: four die attach conditions (no attachment, silicone, polyimide silicone, and silver glass), and two surface conditions (native oxide with and without a few angstroms of vapor-deposited diphenyl siloxane). For a normal silicon cantilever, the work of adhesion seems to be slightly less for the treated surfaces than the untreated, except for the silverglass die attach material. There were at least three orders of magnitude difference in the works of adhesion for the different AFM tip radii. Presumably, the trend is due to some combination of material properties, interfacial roughness, and torque on the AFM cantilever.

Download Full-text

CHANGES IN ADHESION FORCES OF MONTMORILLONITE AND KAOLIN CLAYS AT STRESS PRESSURES

Engineering Geology World ◽

10.25296/1993-5056-2019-14-2-44-59 ◽

2019 ◽

Vol 14 (2) ◽

pp. 44-59

Author(s):

V. V. Seredin ◽

I. V. Lunegov ◽

M. V. Fedorov ◽

N. A. Medvedeva

Keyword(s):

Adhesion Force ◽

Adhesion Forces ◽

Energy Potential ◽

Adhesive Interaction ◽

Adhesive Properties ◽

Clay Particles ◽

Atomic Force ◽

Montmorillonite Clays ◽

Main Factor ◽

Kaolin Clays

For the formation of the technological properties of clays, various methods of their processing have been developed: thermal, chemical, ultraviolet, mechanical, etc. However, the issues of changing the energy properties of the surface of clay particles, previously compacted by stress pressure, are not fully understood. Therefore, the aim of the work is to study the patterns of change in adhesion forces on the surface of particles of montmorillonite and kaolin clays treated with stress pressure up to 800 MPa and a shift of 90°. The adhesion forces of clay samples subjected to stress pressure and shear were studied using an NT-MDT NTEGRA Prima atomic force microscope (Russia). It was experimentally proved that during the machining of kaolin and montmorillonite clays by stress pressure and shear changes in adhesion forces are multidirectional in nature. In kaolin clay, as the pressure increases, the adhesion force increases. In montmorillonite, an increase in pressure up to 150 MPa leads to an increase in the adhesive interaction, a further increase to 800 MPa leads to its decrease. It was revealed that during the processing of clays by stress pressure and shear, the processes of crushing, aggregation and deformation of particles occur in them, leading to a change in the defectiveness of the crystal lattice and the surface of the particles. Such transformations create changes in the energy potential of clay particles, which in turn changes the sorption and adhesive properties of clays. At the same time, in the studied soils the formation of the energy potential on the surface of particles takes place in different ways: in kaolin clays, the main factor is the crushing process, and in montmorillonite — aggregation.

Download Full-text

Capillary Forces Studied with Atomic Force Microscopy

MRS Proceedings ◽

10.1557/proc-1025-b12-07 ◽

2007 ◽

Vol 1025 ◽

Author(s):

Sahar Maghsoudy-Louyeh ◽

Bernhard R. Tittmann

Keyword(s):

Atomic Force Microscopy ◽

Adhesion Force ◽

Theoretical Calculations ◽

Capillary Forces ◽

Adhesion Forces ◽

Coating Materials ◽

Force Microscopy ◽

Atomic Force ◽

Repulsive Forces ◽

Hydrophilic Materials

AbstractThe deposition of films and coatings is sometimes influenced by the presence of small amounts of moisture, which can affect the nucleation and growth processes. It is important to understand the behavior of coating materials–especially in semiconductors–in terms of hydrophilicity/hydrophobicity along with adhesion forces. Our technical approach centers on the use of the atomic force microscope (AFM) which was found to be a reliable tool for studying the surface characteristics of materials. In addition to obtaining topographic information, the AFM can also probe attractive or repulsive forces between the tip and the sample surfaces. In this research, a systematic study of the influence of humidity on the adhesion forces between different AFM tips (silicon and silicon nitride) and both hydrophilic and hydrophobic materials (quartz, calcite, mica, graphite) has been conducted using atomic force microscopy. Several force-distance curves measured by the M5 AFM have been gathered at a series of different humidity levels and different locations on the samples. In this paper, measurements of the adhesion force for hydrophobic and hydrophilic materials versus humidity are presented. The results show that the adhesion force on graphite which has hydrophobic character is independent of humidity variation. Results also show that the adhesion force for fused quartz, mica, and calcite which are hydrophilic materials, change dramatically with increasing humidity due to capillary forces. This is in good agreement with theoretical calculations.

Download Full-text