Bridge Enhanced Nanoscale Impedance Microscopy
- 技術優勢
- · Greater spatial resolution · Greater sensitivity
- 詳細技術說明
- A conductive atomic force microscopy (cAFM) adjunct has been developed by Northwestern scientists that is capable of quantitatively measuring the magnitude and phase of alternating current flow through the tip/sample junction with a five order of magnitude improvement in sensitivity. Significant improvement in sensitivity and spatial resolution will enable the study of electronic behavior in nanomaterials and biological samples. #instrumentation #atomicprobemicroscopy
- *Abstract
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Northwestern scientists have developeda conductive atomic force microscopy (cAFM) adjunct that is capable ofquantitatively measuring the magnitude and phase of alternating current flowthrough the tip/sample junction with a five order of magnitude improvement insensitivity. This technology calledbridge enhanced nanoscale impedance microscopy (BE-NIM) offers significantimprovement in sensitivity and spatial resolution for the study of electronicbehavior in nanomaterials and biological samples. While macroscopic impedance spectroscopytechniques have been employed to characterize alternating current chargetransport for a variety of materials systems and devices, they only reveal anensemble average of the underlying contributions of individual pathways,defects, film thickness variations, electrochemical reactions, and failure mechanisms. Scanning probe impedance measurementtechniques based on the conductive Atomic Force Microscope (cAFM) has enabledprobing current flow and resistivity variations on conductive surfaces withnanoscale spatial resolution; however, fringe capacitance (1-100 picoF) betweenthe sample and the probe imposes a serious detection limit. In an effort to improve the sensitivity ofnanoscale impedance microscopy, BE-NIM offers a variable resistor/capacitor(RC) bridge circuit to cancel the spurious contribution to the AC current flowcaused by fringe capacitance. This addition significantly improves thedetection limit of NIM by at least five orders of magnitude, enabling thedetection of impedance values that are typical for many nanostructures,nano-electrochemical cells, and biological systems.
Applications
· Study of electrical properties ofnanomaterials and biological samples
- *Inventors
- Liam Pingree and Mark Hersam
- 國家/地區
- 美國
