Nanofluidics through a 30-nm aperture nanopipette by applying electrostatic field based on the QTF-AFM system

Nanofluidics of the liquid solution through a 30-nm aperture nanopipette was investgated using the QTF-AFM system. Used pulled nanopipette was attached on the edge of QTF to control the distance between the tip and substrate. Monitored QTF signal was changed by naturally formed water meniscus´s force as tip approached to the sample within 10nm. After forming of water, electric field was applied for the purpose of a filled solution´s extrusion onto the surface. Measured the fluid speed was 43.5 um/s and spread area was 136.6 um² after 5 seconds. During the experiment, temperature was 22 °C and humidity was 20.1 %. Checked thermal drift was 0.3 pm/s.