Development of High-Speed Ion Conductance Microscopy

TL;DR

This paper introduces a high-speed SICM system that significantly improves imaging speed and resolution by using a fast Z-scanner with vibration control and probes with enhanced ion conductance, enabling rapid, high-resolution surface imaging of biological samples.

Contribution

The development of a high-speed SICM with a fast Z-scanner and enhanced ion conductance probes, achieving 100-fold faster imaging and 20 nm spatial resolution.

Findings

Imaging speed increased by 100 times.

Spatial resolution around 20 nm.

Temporal resolution up to 100 kHz.

Abstract

Scanning ion conductance microscopy (SICM) can image the surface topography of specimens in ionic solutions without mechanical probe--sample contact. This unique capability is advantageous for imaging fragile biological samples but its highest possible imaging rate is far lower than the level desired in biological studies. Here, we present the development of high-speed SICM. The fast imaging capability is attained by a fast Z-scanner with active vibration control and pipette probes with enhanced ion conductance. By the former, the delay of probe Z-positioning is minimized to sub-10 us, while its maximum stroke is secured at 6 um. The enhanced ion conductance lowers a noise floor in ion current detection, increasing the detection bandwidth up to 100 kHz. Thus, temporal resolution 100-fold higher than that of conventional systems is achieved, together with spatial resolution around 20 nm.