Nanoscale surface property estimation using proper orthogonal decomposition in atomic force microscopy

CIRP Annals ◽  
2008 ◽  
Vol 57 (1) ◽  
pp. 563-566 ◽  
Author(s):  
S.I. Lee ◽  
S.H. Hong ◽  
J.M. Lee
Keyword(s):  
Atomic Force Microscopy ◽  
Proper Orthogonal Decomposition ◽  
Surface Property ◽  
Orthogonal Decomposition ◽  
Force Microscopy ◽  
Property Estimation ◽  
Atomic Force ◽  
Proper Orthogonal

Proper Orthogonal Decomposition of Tapping Microcantilevers in Liquid Atomic Force Microscopy

2015 ◽  
Author(s):  
Il Kwang Kim ◽  
Soo Il Lee
Keyword(s):  
Atomic Force Microscopy ◽  
Proper Orthogonal Decomposition ◽  
Orthogonal Decomposition ◽  
Modal Decomposition ◽  
Tapping Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Proper Orthogonal Modes ◽  
Proper Orthogonal ◽  
Mode Atomic Force Microscopy

The modal decomposition of tapping mode atomic force microscopy microcantilevers in liquid environments was studied experimentally. Microcantilevers with different lengths and stiffnesses and two sample surfaces with different elastic moduli were used in the experiment. The response modes of the microcantilevers were extracted as proper orthogonal modes through proper orthogonal decomposition. Smooth orthogonal decomposition was used to estimate the resonance frequency directly. The effects of the tapping setpoint and the elastic modulus of the sample under test were examined in terms of their multi-mode responses with proper orthogonal modes, proper orthogonal values, smooth orthogonal modes and smooth orthogonal values. Regardless of the stiffness of the microcantilever under test, the first mode was dominant in tapping mode atomic force microscopy under normal operating conditions. However, at lower tapping setpoints, the flexible microcantilever showed modal distortion and noise near the tip when tapping on a hard sample. The stiff microcantilever had a higher mode effect on a soft sample at lower tapping setpoints. Modal decomposition for tapping mode atomic force microscopy can thus be used to estimate the characteristics of samples in liquid environments.

Studies on Improving PP Fiber Reinforced Concrete

2011 ◽  
Vol 250-253 ◽  
pp. 678-681 ◽  
Author(s):  
Liang Hsing Chou ◽  
Chun Ku Lu ◽  
Maw Tien Lee
Keyword(s):  
Atomic Force Microscopy ◽  
Reinforced Concrete ◽  
Surface Property ◽  
Interaction Force ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Force Curve ◽  
Force Microscopy ◽  
Atomic Force ◽  
Polar Probe

Grafting method was used to modify polypropylene (PP) fiber to enhance the fiber reinforced concrete in this study. Polyacrylamide (PAM) was grafted onto PP surface by UV radiation using benzophenone (BP) as a photoinitiator. The microstructure of PP, and the interaction force between PP and the polar probe were observed with an atomic force microscopy (AFM). Experimental results showed that the roughness of PAM-grafted PP surface decreased significantly in comparison with that of the untreated PP surface. In addition, instead of smooth force curve as that of the untreated PP, the interaction between the probe and PAM-grafted PP surface appeared an oscillation. The above results gave the evidences that PAM had been successfully grafted onto the PP surface as discussed . The high hydrophilic property of PAM modifies the surface property of PP fiber and strengthens PP fiber reinforced concrete.

Empirical Mode Decomposition for Dynamic AFM Microcantilevers in Air and Liquid Environment

2018 ◽  
Author(s):  
Il Kwang Kim ◽  
Jea Woong Jang ◽  
Soo Il Lee
Keyword(s):  
Orthogonal Decomposition ◽  
Operating Conditions ◽  
Liquid Environment ◽  
Tapping Mode ◽  
Force Microscopy ◽  
Hydrodynamic Damping ◽  
Atomic Force ◽  
Mode Decomposition ◽  
Proper Orthogonal ◽  
Smooth Orthogonal Decomposition

The modal decomposition of tapping mode atomic force microscopy microcantilevers in air and liquid environment was experimentally investigated to identify their complex responses. In experiment, the flexible microcantilevers and a flat HOPG sample were used. The responses of the microcantilevers were obtained to extract the linearized modes and orthogonal values using the methods for the proper orthogonal decomposition and the smooth orthogonal decomposition. The influence of the tapping setpoints and the hydrodynamic damping forces were investigated with the multi-mode response of microcantilevers. The results show that the first mode is dominant under normal operating conditions in tapping mode. However, at lower setpoint, the flexible microcantilever behaved uncertain modal distortion near the tip on the sample. The dynamics tapping effect and the damping between microcantilever and liquid influenced their responses.

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