From 71fd667bc99012c595c705d2cb77effd42c85086 Mon Sep 17 00:00:00 2001 From: "W. Trevor King" Date: Thu, 28 Jun 2012 14:44:18 -0400 Subject: [PATCH] Consolidate fig:afm-schematic and fig:piezo-schematic into one figure. Also cite binnig86 (AFM with STM sensor) and meyer88 (AFM with optical lever) when introducing the AFM. --- src/apparatus/afm.tex | 59 +++++++++++++++++++++++-------------------- 1 file changed, 31 insertions(+), 28 deletions(-) diff --git a/src/apparatus/afm.tex b/src/apparatus/afm.tex index ef6babb..234bf98 100644 --- a/src/apparatus/afm.tex +++ b/src/apparatus/afm.tex @@ -10,21 +10,12 @@ transitions in DNA\citep{florin95,rief99} and polysaccharides\citep{rief97a}. An AFM\index{AFM} uses a sharp tip integrated at the end of a -cantilever to interact with the sample. Cantilever bending is -measured by a laser reflected off the cantilever and incident on a -position sensitive photodetector (\cref{fig:afm-schematic}). When the -bending force constant of the cantilever is known\citep{levy02}, the -force applied to the sample can be calculated using Hooke's law -(\cref{eq:sawsim:hooke}). - -\begin{figure} - \asyinclude{figures/schematic/afm}% - \caption{Operating principle for an Atomic Force - Microscope\index{AFM}. A sharp tip integrated at the end of a - cantilever interacts with the sample. Cantilever bending is - measured by a laser reflected off the cantilever and incident on a - position sensitive photodetector.\label{fig:afm-schematic}} -\end{figure} +cantilever to interact with the sample\cite{binnig86}. Cantilever +bending is measured by a laser reflected off the cantilever and +incident on a position sensitive photodetector\cite{meyer88} +(\cref{fig:afm-schematic}). When the bending force constant of the +cantilever is known\citep{levy02}, the force applied to the sample can +be calculated using Hooke's law (\cref{eq:sawsim:hooke}). The substrate is mounted on a three dimensional piezoelectric actuator so that the tip may be positioned on the surface with sub-nanometer @@ -34,19 +25,31 @@ range of TODO in the horizontal directions and a range of TODO in the vertical (\cref{fig:piezo-schematic}). \begin{figure} - \asyinclude{figures/schematic/piezo}% - \caption{Schematic of a tubular piezoelectric actuator. In our AFM, - the substrate is mounted on the top end of the tube, and the - bottom end is fixed to the microscope body. This allows the piezo - to control the relative position between the substrate and the AFM - cantilever. The electrodes are placed so radial electric fields - can be easily generated. These radial fields will cause the piezo - to expand or contract axially. The $z$ voltage causes the tube to - expand and contract uniformly in the axial direction. The $x$ and - $y$ voltages cause expansion on one side of the tube, and - contraction (because of the reversed polarity) on the other side - of the tube. This tilts the tube, shifting the sample - horizontally.\label{fig:piezo-schematic}} + \begin{center} + \subfloat[][]{\label{fig:afm-schematic} + \asyinclude{figures/schematic/afm}} + \hspace{.25in}% + \subfloat[][]{\label{fig:piezo-schematic} + \asyinclude{figures/schematic/piezo}} + \caption{\subref{fig:afm-schematic} Operating principle for an + Atomic Force Microscope\index{AFM}. A sharp tip integrated at + the end of a cantilever interacts with the sample. Cantilever + bending is measured by a laser reflected off the cantilever and + incident on a position sensitive photodetector. + \subref{fig:piezo-schematic} Schematic of a tubular + piezoelectric actuator. In our AFM, the substrate is mounted on + the top end of the tube, and the bottom end is fixed to the + microscope body. This allows the piezo to control the relative + position between the substrate and the AFM cantilever. The + electrodes are placed so radial electric fields can be easily + generated. These radial fields will cause the piezo to expand + or contract axially. The $z$ voltage causes the tube to expand + and contract uniformly in the axial direction. The $x$ and $y$ + voltages cause expansion on one side of the tube, and + contraction (because of the reversed polarity) on the other side + of the tube. This tilts the tube, shifting the sample + horizontally.\label{fig:afm-schematic-and-piezo}} + \end{center} \end{figure} % really, AFM can do this ;) -- 2.26.2