Speaker: Prof. Sang Wook LEE, Department of Physics, Ewha Womans University, Seoul, Korea.

Title: "Nano and Micro-electromechanical mass sensor with sub-zeptogram resolution; 
Towards Single molecule protein sequencing and identification"

Date: Friday, January 16, 2026 - Time: 11 AM
Tea & Coffee: 10:30 AM
Venue: CeNSE Seminar Hall

Abstract:
In this presentation, we will show a electro-mechanical resonant mass sensor utilizing a graphene 
and quartz crystal microbalance, which achieves sub-zeptogram resolution and a single nano 
particle detection under room temperature conditions. Our research indicates that by employing 
Joule heating, the graphene membrane surface can be effectively cleaned, leading to a considerable 
enhancement in the stability of the resonance frequency. By combining machine learning algorithm to
taking frequency shift signal out of thermal fluctuation-oriented noise environment, we could persue 
even higher mass change detection resolution so that it would be possible to recognizing small 
particles, including large proteins and protein complexes by mass detection. We recently developed 
a new idea to detect a single nanoparticle detection out of micro-mechanical system by utilizing 
a complete non-linear resonant state. The ultra-small mass change detection is also performed in 
liquid environment so that this technique can be directly applied to detect a single biomolecule.

Biography:

Prof. Sang Wook Lee received his B.S. degree in 1999 from the Department of Physics at Seoul National 
University, Korea. He subsequently earned his M.S. degree in 2001 and his Ph.D. degree in 2005 from 
the School of Physics, Seoul National University, Seoul, Korea. His research interests include 
nano-transport, nano-electromechanical systems, ultra-sensitive mass and force detection 
using nanomechanical devices, single-molecule protein sequencing, and in-situ electromechanical 
measurements of semiconductor nanowires.

Host Faculty:  Prof. Vini Gautam