The Novel Design of a Nano-Positioner for Interferometer-Based Atomic Force Microscope

Abstract

Conventional AFMs measure cantilever bending, the home-built AFM, developed by Dr. Patil’s group, measures cantilever displacement. This enhanced sensitivity, facilitated by the interfer ometer, enables precise measurements of extremely small amplitudes. Additionally, employing a stiffer cantilever operating in an off-resonance regime is advantageous for experiments conducted in a liquid environment, surpassing the capabilities of traditional AFMs utilised in protein-pulling experiments. The home-built AFM’s current iteration uses an optical fibre setup to construct a Fabry-Perot in terferometer. A TiO2 semi-mirror is coated to the end of a cleaved optical fibre, and when aligned parallel to the cantilever, it forms a Fabry-Perot cavity. However, aligning the optical fibre is challenging and time-consuming, often resulting in sample dehydration. This project aims to devise a novel setup for our AFM to make this alignment procedure easier by making a new design for the home built AFM.