A Technique for the Experimental Determination of the Length and Strength of Adhesive Interactions Between Effectively Rigid Materials

Jacobs, Tevis D. B.; Lefever, Joel A.; Carpick, Robert W.

doi:10.1007/s11249-015-0539-9

Cited by 27 publications

(20 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For tips coated with diamond-like carbon and ultrananocrystalline diamond in contact with a diamond substrate [89], the decrease in adhesion with increasing roughness could be accurately fit using a simplified roughness model, based on a single-scale van der Waals integration. A separate study of silicon tips with a native oxide in contact with diamond [90,91] accounted for the arbitrary roughness of the tip and integrated an interaction potential over the measured geometry. This approach yielded more accurate adhesion parameters than the application of a spherical contact model.…”

Section: Methodsmentioning

confidence: 99%

“…In in situ TEM experiments designed specifically to study nanocontacts, the load resolution of SPM was established in the TEM to investigate dissimilar contacts that do not undergo spontaneous welding [88]. This apparatus has been used to quantitatively characterize the out-of-contact geometry of the SPM tip, as well as to measure the corresponding adhesion [89][90][91], wear [88], and electrical [80] properties. These studies show that, in the general case, there is not fusion of the opposing bodies, but instead, the original interface remains distinct (as shown in Fig.…”

Section: Nanocontacts Explored Using Transmission Electronmentioning

confidence: 99%

See 1 more Smart Citation

Measuring and Understanding Contact Area at the Nanoscale: A Review

Jacobs

Martini

2017

Applied Mechanics Reviews

Self Cite

View full text Add to dashboard Cite

The size of the mechanical contact between nanoscale bodies that are pressed together under load has implications for adhesion, friction, and electrical and thermal transport at small scales. Yet, because the contact is buried between the two bodies, it is challenging to accurately measure the true contact area and to understand its dependence on load and material properties. Recent advancements in both experimental techniques and simulation methodologies have provided unprecedented insights into nanoscale contacts. This review provides a detailed look at the current understanding of nanocontacts. Experimental methods for determining contact area are discussed, including direct measurements using in situ electron microscopy, as well as indirect methods based on measurements of contact resistance, contact stiffness, lateral forces, and topography. Simulation techniques are also discussed, including the types of nanocontact modeling that have been performed and the various methods for extracting the magnitude of the contact area from a simulation. To describe and predict contact area, three different theories of nanoscale contact are reviewed: single-contact continuum mechanics, multiple-contact continuum mechanics, and atomistic accounting. Representative results from nanoscale experimental and simulation investigations are presented in the context of these theories. Finally, the critical challenges are described, as well as the opportunities, on the path to establishing a fundamental and actionable understanding of what it means to be “in contact” at the nanoscale.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Nanocontacts Explored Using Transmission Electronmentioning

confidence: 99%

Measuring and Understanding Contact Area at the Nanoscale: A Review

Jacobs

Martini

2017

Applied Mechanics Reviews

Self Cite

View full text Add to dashboard Cite

show abstract

“…The SNAP method is summarized here, and described in more detail in ref. [ 20 ] . Mathematically, the total interaction force between the tip and sample F tip/sample can be calculated by integrating the commonly used LennardJones 3-9 traction-separation relation [ 4,5,8,48 ] over the geometry of the tip.…”

Section: Methodsmentioning

confidence: 99%

“…This allows simultaneous extraction of both W adh,int and z 0 ; the technique is summarized in the methods sectiontechnical details can be found elsewhere. [ 20 ] In the present paper, this technique is applied to silicon AFM probes (with native oxide) in contact with a fl at singlecrystal diamond punch in order to measure W adh,int and z 0 for this interface. Silicon is widely used for microscopy and device applications.…”

Section: Introductionmentioning

confidence: 99%

Measurement of the Length and Strength of Adhesive Interactions in a Nanoscale Silicon–Diamond Interface

Jacobs¹,

Lefever²,

Carpick³

2015

Adv Materials Inter

Self Cite

View full text Add to dashboard Cite

the interaction (characterized by the range of adhesion z 0 ).The intrinsic work of adhesion W adh is the energy per unit area required to separate two planar surfaces from equilibrium contact to infi nite separation. In terms of surface energy (γ i of surface i ) and interfacial energy (γ ij between surfaces i and j ), the work of adhesion is calculated as follows:In accordance with prior literature on adhesion and roughness, [ 9 ] the intrinsic work of adhesion W adh,int is defi ned as the work of adhesion between two perfectly fl at, planar surfaces. While W adh,int is a continuum concept, it can be robustly mapped onto an atomistic description of two atomically fl at, single-crystal surfaces in contact. The effective work of adhesion, W adh,eff , is defi ned as the work of adhesion for the same material pair and the same global geometry (planar), but with the addition of local surface roughness on one or both surfaces. The distinction between W adh,int and W adh,eff is shown schematically in Figure 1 . The W adh,int is determined by the identity of the materials in contact, and the environment, whereas W adh,eff is a function of W adh,int and the local surface topography. For hard, non-conforming materials, W adh,eff is typically much smaller than W adh,int . The primary reason for this is that the roughness increases the effective separation between the two materials, and therefore signifi cantly increases γ ij between the materials as they can no longer make intimate contact. Roughness can also increase the surface energies γ i and γ j , but this effect is typically overwhelmed by the change in γ ij . This distinction is drawn because many experimental techniques exist to measure W adh,eff (for example, using microfabricated beam tests [ 10 ] ), but generally applicable techniques to deduce from this the W adh,int are not well established.Physically, z 0 describes the equilibrium separation distance between perfectly fl at surfaces, i.e., the separation distance at which their interaction force is zero. However, in many mathematical descriptions of adhesion (for instance, refs. [ 5,7,8,11 ] ) z 0 also scales the distance over which adhesion acts for a particular material. Therefore, the parameter z 0 is referred to in this paper as the "range of adhesion," (in accordance with Greenwood, [ 5 ] who calls it the "range of action of the surface forces").The adhesive interactions between nanoscale silicon atomic force microscope (AFM) probes and a diamond substrate are characterized using in situ adhesion tests inside of a transmission electron microscope (TEM). In particular, measurements are presented both for the strength of the adhesion acting between the two materials (characterized by the intrinsic work of adhesion W adh,int ) and for the length scale of the interaction (described by the range of adhesion z 0 ). These values are calculated using a novel analysis technique that requires measurement of the AFM probe geometry, the adhesive force, and the position where the snap-in instability occurs. Values ...

show abstract

“…With partial support from AOARD, we developed a novel experimental technique to simultaneously determine both the work of adhesion and range of adhesion 34,35 . The experiments were conducted for the silicon-diamond contact pair, but the method is general and will be applied to the UNCD-diamond system we are working with presently.…”

Section: Length and Strength Of Adhesive Interactions Between Siliconmentioning

confidence: 99%

Understanding the Atomic Scale Mechanisms that Control the Attainment of Ultralow Friction and Wear in Carbon-Based Materials

Carpick¹,

Jeng²

2016

View full text Add to dashboard Cite

REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Executive Services, Directorate (0704-0188). Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ORGANIZATION. REPORT DATE (DD-MM-YYYY)16 SPONSOR/MONITOR'S ACRONYM(S)AFRL/AFOSR/IOA(AOARD) SPONSOR/MONITOR'S REPORT NUMBER(S)14IOA087_144071 12. DISTRIBUTION/AVAILABILITY STATEMENT Distribution Code A: Approved for public release, distribution is unlimited. SUPPLEMENTARY NOTES ABSTRACTThe wear behavior of ultrananocrystalline diamond (UNCD) was characterized at the nanoscale to understand the fundamental mechanisms controlling the initial stages of wear. To enable this, novel nanoscale sliding experiments were conducted in situ in a transmission electron microscope (TEM). UNCD is part of a class of materials with tremendous potential for tribological applications due to their low wear and low friction behavior. However, the scientific understanding of the initial wear process is lacking, and this prevents broader application of these materials. The experiments revealed that: (1) the wear follows a gradual, atomic-level removal mechanism, as opposed to fracture or plastic deformation; (2) the rate of wear (rate of material removal) in this nanoscale, single asperity contact is orders of magnitude larger than that measured at the macroscale; and (3) nevertheless, the wear follows the macroscale trend of an initially larger wear rate, followed by stabilization at a lower value. Strikingly, no amorphization during sliding was observed, in contrast with previous experimental and computational results for diamond. To better understand the contact stresses that drive the wear, a careful, long-range investigation of contact behavior was also initiated. Since adhesion is crucial in determining contact stresses, an experimental method for the nanoscale measurement of length and strength of adhesive interactions between asperities of arbitrary shape was successfully implemented. The wear behavior of ultrananocrystalline diamond (UNCD) was characterized at the nanoscale to understand the fundamental mechanisms controlling the initial stages of wear. To enable this, novel nanoscale sliding experiments were conducted in situ in a transmission electron microscope (TEM). UNCD is part of a class of materials with tremendous potential for tribological applications due to their low wear and low frict...

show abstract

A Technique for the Experimental Determination of the Length and Strength of Adhesive Interactions Between Effectively Rigid Materials

Cited by 27 publications

References 30 publications

Measuring and Understanding Contact Area at the Nanoscale: A Review

Measuring and Understanding Contact Area at the Nanoscale: A Review

Measurement of the Length and Strength of Adhesive Interactions in a Nanoscale Silicon–Diamond Interface

Understanding the Atomic Scale Mechanisms that Control the Attainment of Ultralow Friction and Wear in Carbon-Based Materials

Contact Info

Product

Resources

About