14 results match your criteria calculated force-indentation

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Evaluating Young's Modulus of Single Yeast Cells Based on Compression Using an Atomic Force Microscope with a Flat Tip.

Microsc Microanal 2021 Jan 15:1-8. Epub 2021 Jan 15.

Department of Micro-Nano Mechanical Science and Engineering, Nagoya University, Room 108, Aerospace Mechanical Engineering Research Building, Furo-cho, Chikusa-ku, Nagoya, Aichi464-8603, Japan.

In this research, atomic force microscopy (AFM) with a flat tip cantilever is utilized to measure Young's modulus of a whole yeast cell (Saccharomyces cerevisiae BY4741). The results acquired from AFM are similar to those obtained using a microfluidic chip compression system. The mechanical properties of single yeast cells are important parameters which can be examined using AFM. Read More

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January 2021

Quantitative mechanical analysis of indentations on layered, soft elastic materials.

Soft Matter 2019 Feb;15(8):1776-1784

Department of Physics, Arizona State University, Tempe, AZ 85287, USA.

Atomic force microscopy (AFM) is becoming an increasingly popular method for studying cell mechanics, however the existing analysis tools for determining the elastic modulus from indentation experiments are unable to quantitatively account for mechanical heterogeneity commonly found in biological samples. In this work, we numerically calculated force-indentation curves onto two-layered elastic materials using an analytic model. We found that the effect of the underlying substrate can be quantitatively predicted by the mismatch in elastic moduli and the homogeneous-case contact radius relative to the layer height for all tested probe geometries. Read More

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February 2019

Measurement of corneal tangent modulus using ultrasound indentation.

Ultrasonics 2016 09 19;71:20-28. Epub 2016 May 19.

Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China. Electronic address:

Biomechanical properties are potential information for the diagnosis of corneal pathologies. An ultrasound indentation probe consisting of a load cell and a miniature ultrasound transducer as indenter was developed to detect the force-indentation relationship of the cornea. The key idea was to utilize the ultrasound transducer to compress the cornea and to ultrasonically measure the corneal deformation with the eyeball overall displacement compensated. Read More

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September 2016

Stiffness of cancer cells measured with an AFM indentation method.

J Mech Behav Biomed Mater 2015 Sep 13;49:105-11. Epub 2015 May 13.

Department of Biomedical Engineering, School of Engineering, Okayama University of Science, 1-1 Ridai-cho, Kita-ku, Okayama 700-0001, Japan. Electronic address:

The stiffness of cancer cells and its changes during metastasis are very important for understanding the pathophysiology of cancer cells and the mechanisms of metastasis of cancer. As the first step of the studies on the mechanics of cancer cells during metastasis, we determined the elasticity and stiffness of cancer cells with an indentation method using an atomic force microscope (AFM), and compared with those of normal cells. In most of the past AFM studies, Young׳s elastic moduli of cells have been calculated from force-indentation data using Hertzian model. Read More

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September 2015

Do the mechanical and chemical properties of InvisalignTM appliances change after use? A retrieval analysis.

Eur J Orthod 2016 Feb 3;38(1):27-31. Epub 2015 Mar 3.

***Clinic of Orthodontics and Paediatric Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland

Aim: To investigate the mechanical and chemical alterations of Invisalign appliances after intraoral aging.

Materials And Methods: Samples of Invisalign appliances (Align Technology, San Jose, California, USA) were collected following routine treatment for a mean period of 44±15 days (group INV), whereas unused aligners of the same brand were used as reference (group REF). A small sample from the central incisors region was cut from each appliance and the buccal surface was analysed by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy (n = 5). Read More

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February 2016

Determination of the elastic properties of tomato fruit cells with an atomic force microscope.

Sensors (Basel) 2013 Sep 11;13(9):12175-91. Epub 2013 Sep 11.

Institute of Agrophysics, Polish Academy of Sciences, Doswiadczalna 4, Lublin 20-290, Poland.

Since the mechanical properties of single cells together with the intercellular adhesive properties determine the macro-mechanical properties of plants, a method for evaluation of the cell elastic properties is needed to help explanation of the behavior of fruits and vegetables in handling and food processing. For this purpose, indentation of tomato mesocarp cells with an atomic force microscope was used. The Young's modulus of a cell using the Hertz and Sneddon models, and stiffness were calculated from force-indentation curves. Read More

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September 2013

Pore-spanning lipid membrane under indentation by a probe tip: a molecular dynamics simulation study.

Langmuir 2011 Oct 7;27(19):11930-42. Epub 2011 Sep 7.

Department of Engineering and System Science, National Tsing Hua University, Taiwan, Republic of China.

We study the indentation of a free-standing lipid membrane suspended over a nanopore on a hydrophobic substrate by means of molecular dynamics simulations. We find that in the course of indentation the membrane bends at the point of contact and the fringes of the membrane glide downward intermittently along the pore edges and stop gliding when the fringes reach the edge bottoms. The bending continues afterward, and the large strain eventually induces a phase transition in the membrane, transformed from a bilayered structure to an interdigitated structure. Read More

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October 2011

Primate lens capsule elasticity assessed using Atomic Force Microscopy.

Exp Eye Res 2011 Jun 21;92(6):490-4. Epub 2011 Mar 21.

Department of Biomedical Engineering, University of Miami, College of Engineering, 1251 Memorial Drive, McArthur Annex Room 209, Coral Gables, FL 33146, USA.

The purpose of this project is to measure the elasticity of the human and non-human primate lens capsule at the microscopic scale using Atomic Force Microscopy (AFM). Elasticity measurements were performed using AFM on the excised anterior lens capsule from 9 cynomolgus monkey (5.9-8. Read More

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AFM stiffness nanotomography of normal, metaplastic and dysplastic human esophageal cells.

Phys Biol 2011 Feb 7;8(1):015007. Epub 2011 Feb 7.

Department of Physics, Arizona State University, Tempe, AZ 85287, USA.

The mechanical stiffness of individual cells is important in tissue homeostasis, cell growth, division and motility, and the epithelial-mesenchymal transition in the initiation of cancer. In this work, a normal squamous cell line (EPC2) and metaplastic (CP-A) as well as dysplastic (CP-D) Barrett's Esophagus columnar cell lines are studied as a model of pre-neoplastic progression in the human esophagus. We used the combination of an atomic force microscope (AFM) with a scanning confocal fluorescence lifetime imaging microscope to study the mechanical properties of single adherent cells. Read More

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February 2011

Probing the morphology and nanoscale mechanics of single poly(N-isopropylacrylamide) microgels across the lower-critical-solution temperature by atomic force microscopy.

Small 2008 Jan;4(1):119-26

Materials Science and Technology of Polymers, Faculty of Science and Technology, and MESA Institute for Nanotechnology, University of Twente, PO Box 217, 7500AE Enschede, The Netherlands.

Submicrometer-sized particles of poly(N-isopropylacrylamide) (PNIPAM) are synthesized by surfactant-free radical polymerization. The morphology and nanomechanical properties of individual, isolated PNIPAM microgel particles at the silicon/air and silicon/water interfaces, below and above the PNIPAM volume-phase-transition temperature (VPTT), are probed by atomic force microscopy. In air, and in water below the VPTT, the PNIPAM spheres are flattened and adopt a pancakelike shape. Read More

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January 2008

Studying the mechanics of cellular processes by atomic force microscopy.

Methods Cell Biol 2007 ;83:347-72

Institute of Biophysics, University of Bremen, Bremen 28334, Germany.

The mechanical properties of cells are important for many cellular processes like cell migration, cell protrusion, cell division, and cell morphology. Depending on cell type, the mechanical properties of cells are determined mainly by the cell wall or the interior cytoskeleton. In eukaryotic cells, the stiffness is mainly determined by the cytoskeleton, which is made of several polymeric networks, including actin, microtubuli, and intermediate filaments. Read More

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Atomic force microscopy measurements of lens elasticity in monkey eyes.

Mol Vis 2007 Apr 2;13:504-10. Epub 2007 Apr 2.

The Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA.

Purpose: To demonstrate the feasibility of measuring the elasticity of intact crystalline lenses using atomic force microscopy (AFM).

Methods: AFM elasticity measurements were performed on intact lenses from 18 fresh cynomolgus monkey cadaver eyes (4-10 years old, <1 day postmortem) that had been left attached to their zonule-ciliary body-sclera framework. The eyes were prepared by bonding a plastic ring on the sclera after removal of the conjunctival, adipose, and muscle tissues. Read More

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Micromechanical bending of single collagen fibrils using atomic force microscopy.

J Biomed Mater Res A 2007 Jul;82(1):160-8

Polymer Chemistry and Biomaterials, Faculty of Science and Technology and Institute of Biomedical Technology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands.

A new micromechanical technique was developed to study the mechanical properties of single collagen fibrils. Single collagen fibrils, the basic components of the collagen fiber, have a characteristic highly organized structure. Fibrils were isolated from collagenous materials and their mechanical properties were studied with atomic force microscopy (AFM). Read More

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Hardness measured with traditional Vickers and Martens hardness methods.

Dent Mater 2007 Sep 4;23(9):1079-85. Epub 2006 Dec 4.

Department of Restorative Dentistry, School of Dental Sciences, University of Newcastle upon Tyne, UK.

Objective: To determine the differences, if any, between hardness measured with traditional Vickers and Martens hardness test methods on denture teeth under 2, 10 and 50 N loads.

Method: Hardness of acrylic resin (VIV), composite resin (ORT) and porcelain (POR) denture tooth materials was measured using a traditional Vickers hardness (HV) method and Martens hardness (HM) method at 2, 10 and 50N test loads. Vickers hardness was also calculated from the force-indentation depth curves (HVfid) that were recorded during Martens hardness. Read More

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September 2007
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