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Bias Modulated Scanning Ion Conductance Microscopy (BM-SICM). David Perry The University of Warwick Electrochemistry and Interfaces Group. SICM. Novak et al., Nature Methods 6 , 279 (2009). SICM. V. Ag/AgCl Electrodes. Tip Diameter. 100 mM KCl. Ionic Current.
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Bias Modulated Scanning Ion Conductance Microscopy (BM-SICM) David Perry The University of Warwick Electrochemistry and Interfaces Group
SICM Novak et al., Nature Methods 6 , 279 (2009)
SICM V Ag/AgCl Electrodes Tip Diameter 100 mM KCl Ionic Current Tip-Substrate Separation Tip Diameter Substrate
SICM V Ag/AgCl Electrodes Tip Diameter 100 mM KCl Ionic Current Tip-Substrate Separation Tip Diameter Substrate
SICM V Ag/AgCl Electrodes Tip Diameter 100 mM KCl Ionic Current Tip-Substrate Separation Tip Diameter Substrate
Distance Modulated SICM Tip Diameter V DC Current Tip-Substrate Separation AC Amplitude Tip Diameter Substrate
A Simple Alternative-Bias Modulation • No physical oscillation of tip • Can perform about 0V • Potential to scan at wide range of frequencies • Easier to model
Bias Modulated SICM Bias +10 mV 0 mV -10 mV DC Current Tip Diameter Substrate McKelvey et al., Anal. Chem. 86, 3639−3646 (2014)
Bias Modulated SICM Bias +10 mV 0 mV -10 mV DC Current Tip Diameter Substrate
Bias Modulated SICM Bias +10 mV 0 mV -10 mV DC Current Tip Diameter Substrate
Bias Modulated SICM Bias +10 mV 0 mV -10 mV DC Current Tip Diameter Substrate
Bias Modulated SICM Bias +10 mV 0 mV -10 mV DC Current Tip Diameter Substrate
Bias Modulated SICM Bias +10 mV 0 mV -10 mV DC Current Tip Diameter Substrate
Bias Modulated SICM Bias +10 mV 0 mV -10 mV DC Current Tip Diameter Substrate
Bias Modulated SICM Bias +10 mV 0 mV -10 mV DC Current Tip Diameter Substrate
Bias Modulated SICM Bias +10 mV 0 mV -10 mV DC Current Tip Diameter Substrate
Bias Modulated SICM Bias +10 mV 0 mV -10 mV DC Current Tip Diameter Substrate
Experimental Approach Curves McKelvey et al., Anal. Chem. 86, 3639−3646 (2014)
Equivalent Circuit Model McKelvey et al., Anal. Chem. 86, 3639−3646 (2014)
Theoretical Approach Curves McKelvey et al., Anal. Chem. 86, 3639−3646 (2014)
Experimental Vs. Theoretical Theoretical Experimental
Distance Vs. Bias Modulated GLASS GOLD McKelvey et al., Anal. Chem. 86, 3639−3646 (2014)
Topographical Mapping of Calcite AC Phase Set Point AC Amplitude Set Point
Conclusions • SICM is a powerful tool for non-contact imaging • Improved feedback in the form of bias modulation • Large feedback signal over a range of frequencies • Good theoretical model • Can scan topography using either AC amplitude or AC phase • Extend SICM as a tool for functional imaging
Acknowledgements • Dr. Kim McKelvey • Sophie Kinnear • Dr. Dmitry Momotenko • Prof. Patrick Unwin