Oral, Ahmet
The mechanical properties of very small volumes of material can vary greatly from bulk properties. These modified properties are of interest in many areas including the operation of atomic force microscopy (AFM), the study of adhesion and fracture, and the evaluation of electrical contact response. Despite the importance of these properties, AFM has not yet been successfully utilized for their investigation. Most existing AFMs still rely on the control and monitoring of displacements, with forces being inferred from spring constants. This would be fine if other interactions, such as those between the tip and the surface, were minor perturbations. However, this is frequently not the case, particularly for contact mode AFM. Hence very little is known about the forces applied in the contact and their affect on both the tip and the sample. In this article we describe an AFM probe where forces rather than displacements are applied to the tip. This allows absolute determination of contact compliance and hence provides a measure of the tip-surface interaction. As an example of its use we show quantitatively the effect of the adsorbed water and meniscus forces present in ambient probe microscopy.


A 5-Parameter Isothermal Creep Model For Polymeric Liners
Güner, Doğukan; Öztürk, Hasan (null; 2019-07-12)
Polymeric materials are commonly used as load-carrying components in different structural applications due to the ease of manufacture, installation and long lifetime properties. In civil and mining engineering applications, fast-setting thin polymeric liners are in demand as areal support elements in underground openings. The stability of the openings is maintained by polymeric liners that might sustain the constant loads due to the presence of wedge blocks. Therefore, their time-dependent mechanical respo...
A data-informatics method to quantitatively represent ternary eutectic microstructures
Sargın, Irmak; Beckman, Scott P. (2019-02-01)
Many of the useful properties of modern engineering materials are determined by the material's microstructure. Controlling the microstructure requires an understanding of the complex dynamics underlying its evolution during processing. Investigating the thermal and mass transport phenomena responsible for a structure requires establishing a common language to quantitatively represent the microstructures being examined. Although such a common language exists for some of the simple structures, which has allow...
A joint density functional and classical molecular dynamics study on interface characteristics of graphene and polyetheretherketone
Sert, Elif; Toffoli, Hande; Department of Physics (2020-10-9)
Graphene is a single layer allotrope of carbon with a honeycomb arrangement of atoms, characterized by excellent mechanical properties such as high tensile strength, high Young’s modulus as well as desirable electrical properties such as high electron mobility. Due to these superior properties, it is considered an important material in numerous technological applications. Among these, graphene-polymer composites have attracted significant interest in the materials research community in recent years. T...
A Wireless Metamaterial-Inspired Passive Rotation Sensor With Submilliradian Resolution
Gargari, Ali Maleki; Ozbey, Burak; DEMİR, Hilmi Volkan; ALTINTAŞ, AYHAN; Albostan, Utku; Kurç, Özgür; ERTÜRK, VAKUR BEHÇET (2018-06-01)
A novel passive wireless rotation sensing system with high levels of sensitivity and resolution is proposed and demonstrated for measuring elastic-region bending in materials such as steel. This system is composed of a transceiver antenna and a double-plate sensor in the form of an inter-digital configuration, which does not incorporate any active component. The sensor exhibits a large rotation resolution of 20 mu-rad, an excellent sensitivity of 28 MHz/degrees in average, and a large linear dynamic range o...
A Study on the tensile strength of compacted Ankara clay and kaolin clay
Dağar, Volkan; Çokça, Erdal; Department of Civil Engineering (2017)
Tensile strength of clay, is a major mechanical parameter and is the main controlling parameter of tensile crack development which is generally encountered in geostructures. The researches to determine the tensile strength of clays are very limited. There are two kinds of methods which are used to measure the tensile strength of soils and these are named as, indirect and direct methods. In this experimental study, a direct tensile test apparatus was developed for measurement and understanding of the tensile...
Citation Formats
S. P. JARVİS, A. Oral, T. P. WEİHS, and J. B. PETHİCA, “A NOVEL FORCE MICROSCOPE AND POINT-CONTACT PROBE,” REVIEW OF SCIENTIFIC INSTRUMENTS, pp. 3515–3520, 1993, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/33151.