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Biomedical Engineering and Bioengineering

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Friction

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Full-Text Articles in Engineering

Motion And Force Transmission Of A Flexible Instrument Inside A Curved Endoscope, Jitendra P. Khatait Sep 2013

Motion And Force Transmission Of A Flexible Instrument Inside A Curved Endoscope, Jitendra P. Khatait

Jitendra P Khatait

Flexible instruments are increasingly used to perform advanced and complex surgical procedures either manually or robotically. The success of flexible instruments in surgery requires high motion and force fidelity, and controllability of the tip. However, the friction and the limited stiffness of such instruments limit their motion and force transmission. The implementation of flexible instruments in surgery necessitates their characterization, the development of proper tools to understand the effect of various mechanical parameters on their overall performance, and an improvement in motion and force fidelity. Therefore, this thesis describes 2-D and 3-D flexible multibody models of a flexible surgical instrument …


Quantitative Assessment Of Sample Stiffness And Sliding Friction From Force Curves In Atomic Force Microscopy, Nancy Burnham, Jon Pratt, Gordon Shaw, Lee Kumanchik Feb 2010

Quantitative Assessment Of Sample Stiffness And Sliding Friction From Force Curves In Atomic Force Microscopy, Nancy Burnham, Jon Pratt, Gordon Shaw, Lee Kumanchik

Nancy A. Burnham

It has long been recognized that the angular deflection of an atomic force microscope(AFM) cantilever under “normal” loading conditions can be profoundly influenced by the friction between the tip and the surface. It is shown here that a remarkably quantifiable hysteresis occurs in the slope of loading curves whenever the normal flexural stiffness of the AFM cantilever is greater than that of the sample. This situation arises naturally in cantilever-on-cantilever calibration, but also when trying to measure the stiffness of nanomechanical devices or test structures, or when probing any type of surface or structure that is much more compliant along …