Speaker Introduction

Dr. Bing-Sui Lu received his BA in Physics and Certificate of Advanced Study in Mathematics with Distinction from the University of Cambridge in 2004. After an obligatory two-year stint with the Singaporean army, he enrolled in graduate school at the University of Illinois at Urbana-Champaign, receiving his Ph.D. in Physics in 2012. Prior to joining the American University of Sharjah in 2025, he has worked at the Institute of Natural Sciences, Shanghai Jiaotong University, the University of Ljubljana, Jozef Stefan Institut, Nanyang Technological University, Xi'an Jiaotong-Liverpool University and Thammasat University.

Abstract

There is a great interest in the behavior of systems at the micrometer and nanometer scales. At such length scales, forces which are typically negligible in everyday experience become significant. An example of such forces would be the van der Waals/Casimir force and the Casimir-Polder force. Owing to the van der Waals/Casimir force, bodies can attract each other even though they are overall charge neutral, and this could explain how geckos manage to stick to walls. Atoms are also attracted to surfaces because of the Casimir-Polder force. Another source of attractive interactions between overall charge neutral bodies is the presence of random impurity charges trapped inside the bodies during the fabrication process. In this seminar, I will describe the behavior of the interaction between two planar bodies and the interaction between an atom and a dielectric body that arise from such quenched charge disorder. I will also show how the quenched charge disorder can give rise to a frictional force if two planar bodies are moving past each other even though they are not in contact.