Electric-Double-Layer Oriented Field-Screening Effect on High-Resolution Electromechanical Imaging in Conductive Solutions

Abstract

What if scanning probe microscopy (SPM) could be used in water? $I\phantom{\rule{0}{0ex}}n$ $v\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}v\phantom{\rule{0}{0ex}}o$ or $i\phantom{\rule{0}{0ex}}n$ $o\phantom{\rule{0}{0ex}}p\phantom{\rule{0}{0ex}}e\phantom{\rule{0}{0ex}}r\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}d\phantom{\rule{0}{0ex}}o$ detection of the electrical properties of functional systems in polar liquids by SPM is in high demand, in many research domains. Progress has been thwarted, though, because the physical mechanism behind the imaging difficulties in such an environment is still ambiguous. This study clarifies the physics by simulating electric field screening based on the formation of electric double layers at the solid-liquid interfaces of the metal tip and sample. Visualizing the electromechanical coupling on ferroelectrics experimentally confirms the screening effect in electrolytes.