Mass Detection in Viscous Fluid Utilizing Vibrating Micro- and Nanomechanical Mass Sensors under Applied Axial Tensile Force.
Vibrating micro- and nanomechanical mass sensors are capable of quantitatively determining attached mass from only the first three (two) measured cantilever (suspended) resonant frequencies. However, in aqueous solutions that are relevant to most biological systems, the mass determination is challenging because the quality factor (Q-factor) due to fluid damping decreases and, as a result, usually just the fundamental resonant frequencies can be correctly identified. Moreover, for higher modes the resonance coupling, noise, and internal damping have been proven to strongly affect the measured resonances and, correspondingly, the accuracy of estimated masses. In this work, a technique capable of determining the mass for the cantilever and also the position of nanobeads attached on the vibrating micro-/nanomechanical beam under intentionally applied axial tensile force from the measured fundamental flexural resonant frequencies is proposed. The axial force can be created and controlled through an external electrostatic or magnetostatic field. Practicality of the proposed technique is confirmed on the suspended multi-walled carbon nanotube and the rectangular silicon cantilever-based mass sensors. We show that typically achievable force resolution has a negligibly small impact on the accuracy of mass measurement.
Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 80778, Taiwan. stachiv@fzu.cz.|Institute of Physics, Czech Academy of Sciences, Prague 18221, Czech Republic. stachiv@fzu.cz.
Ivo
I
Stachiv
Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 80778, Taiwan. fang@kuas.edu.tw.
Te-Hua
TH
Fang
Advanced Institute of Manufacturing with High-tech Innovations (AIM-HI), National Chung Cheng University, Chiayi County 62102, Taiwan. imeyrj@ccu.edu.tw.|Department of Mechanical Engineering, National Chung Cheng University, Chiayi County 62102, Taiwan. imeyrj@ccu.edu.tw.
Yeau-Ren
YR
Jeng
beam under tension; cantilever mass sensors; carbon nanotube; mass detection in fluid; mass resonator sensors; resonant frequency; viscous fluid