Removing Material Using Atomic Force Microscopy with Single‐ and Multiple‐Tip Sources

Abstract

Atomic force microscopy (AFM) has been an effective material removing tool for fabricating various nanostructures because of its sub-nanometer precision and simplicity in operation. AFM material removing techniques have evolved from a solely mechanical process to one in which the tip can be loaded by additional energy sources, such as thermal, electric, or chemical, to enhance its fabrication abilities. In this paper, these material removing techniques are reviewed with an emphasis on their capabilities and recent progress. The recent hardware and software developments are first presented to provide a general view on the current status of the technology to be assessed. Following an overview of the feasibility and effectiveness of using mechanical scratching for removing various types of soft and hard materials, the processes of a wide range of approaches using multiple tip sources are then assessed with a focus on their principles, versatilities, and potentials for future applications.

pH-Dependent Formation and Disintegration of the Influenza A Virus Protein Scaffold To Provide Tension for Membrane Fusion

“…All of the images obtained had dimensions of 1 by 1 m 2 . When the protein layer was very dense, we used a nanolithography technique to determine the actual thickness of the adsorbed layer (42,43). For that, we increased the image size to 3 by 3 m 2 , switched the microscope to the contact mode, and scratched a protein layer patch with dimensions of 0.7 by 0.7 m 2 off using a cantilever with a nominal spring constant of 0.12 N/m and a tip radius of approximately 10 nm (Bruker).…”

“…To test this prediction, 3:7 DOPS-DOPC LUVs were loaded with the highly fluorescent Tb 3ϩ -DPA complex with EDTA in the outer buffer. EDTA chelates Tb 3ϩ so that leakage of liposomes would result in a decrease in total fluorescence (42). As we are interested in the disintegrating effect of M1 only, we needed to subtract from the observed total leakage any possible component of leakage due to vesicle fusion, which is expected to take place at an acidic pH.…”

Nondestructive tribochemistry-assisted nanofabrication on GaAs surface

“…Just like the electrochemical reaction during local anode oxidation, tribochemical reaction provides additional energy loading pathway for the material removal17. However, the contact pressures P c during anodic oxidation by Pt-coated AFM tip was estimated to be 1 ~ 2 GPa when the tip radius was about 50 nm38, which was still higher than the contact pressure during the tribochemistry-assisted nanofabrication in this study.…”

“…It is well-known that grooves could be formed on a surface when the yield of material occurred1718. When a diamond tip was used, the lowest limit of the contact pressure for the fabrication of grooves on GaAs surface was about 4.9 GPa, under which the contact area of GaAs yielded (Supplementary Section 1).…”

Subnanomachining by Ultrasonic-Vibration-Assisted Atomic Force Microscopy

“…With the rise in interest in both novel and biological materials, AFM nanomachining on graphene [20] and cell walls [21] have also been studied. However, direct AFM nanomachining is limited in fabrication speed and performance [22]. At the same time, the large normal force leads to considerable tip wear.…”