Frequency modulation atomic force microscopy in ambient environments utilizing robust feedback tuning

Files in This Item:
File Description SizeFormat 
RevSciInstrum_80_023701.pdf819.32 kBAdobe PDFDownload
Title: Frequency modulation atomic force microscopy in ambient environments utilizing robust feedback tuning
Authors: Kilpatrick, J. I.
Gannepalli, A.
Cleveland, J. P.
Jarvis, Suzi
Permanent link:
Date: 2-Feb-2009
Abstract: Frequency modulation atomic force microscopy (FM-AFM) is rapidly evolving as the technique of choice in the pursuit of high resolution imaging of biological samples in ambient environments. The enhanced stability afforded by this dynamic AFM mode combined with quantitative analysis enables the study of complex biological systems, at the nanoscale, in their native physiological environment. The operational bandwidth and accuracy of constant amplitude FM-AFM in low Q environments is heavily dependent on the cantilever dynamics and the performance of the demodulation and feedback loops employed to oscillate the cantilever at its resonant frequency with a constant amplitude. Often researchers use ad hoc feedback gains or instrument default values that can result in an inability to quantify experimental data. Poor choice of gains or exceeding the operational bandwidth can result in imaging artifacts and damage to the tip and/or sample. To alleviate this situation we present here a methodology to determine feedback gains for the amplitude and frequency loops that are specific to the cantilever and its environment, which can serve as a reasonable "first guess", thus making quantitative FM-AFM in low Q environments more accessible to the nonexpert. This technique is successfully demonstrated for the low Q systems of air (Q∼40) and water (Q∼1). In addition, we present FM-AFM images of MC3T3-E1 preosteoblast cells acquired using the gains calculated by this methodology demonstrating the effectiveness of this technique.
Type of material: Journal Article
Publisher: American Institute of Physics
Journal: Review of Scientific Instruments
Volume: 80
Issue: 2
Start page: 023701
End page: 023701-6
Copyright (published version): 2009 American Institute of Physics
Keywords: Atomic force microscopyBiological techniquesCantileversCellular biophysicsDemodulationFeedbackFrequency modulation
DOI: 10.1063/1.3073964
Language: en
Status of Item: Not peer reviewed
Appears in Collections:Conway Institute Research Collection

Show full item record

Citations 10

Last Week
Last month
checked on Oct 11, 2018

Google ScholarTM



This item is available under the Attribution-NonCommercial-NoDerivs 3.0 Ireland. No item may be reproduced for commercial purposes. For other possible restrictions on use please refer to the publisher's URL where this is made available, or to notes contained in the item itself. Other terms may apply.