scholarly journals High-bandwidth multimode self-sensing in bimodal atomic force microscopy

2016 ◽  
Vol 7 ◽  
pp. 284-295 ◽  
Author(s):  
Michael G Ruppert ◽  
S O Reza Moheimani

Using standard microelectromechanical system (MEMS) processes to coat a microcantilever with a piezoelectric layer results in a versatile transducer with inherent self-sensing capabilities. For applications in multifrequency atomic force microscopy (MF-AFM), we illustrate that a single piezoelectric layer can be simultaneously used for multimode excitation and detection of the cantilever deflection. This is achieved by a charge sensor with a bandwidth of 10 MHz and dual feedthrough cancellation to recover the resonant modes that are heavily buried in feedthrough originating from the piezoelectric capacitance. The setup enables the omission of the commonly used piezoelectric stack actuator and optical beam deflection sensor, alleviating limitations due to distorted frequency responses and instrumentation cost, respectively. The proposed method benefits from a more than two orders of magnitude increase in deflection to strain sensitivity on the fifth eigenmode leading to a remarkable signal-to-noise ratio. Experimental results using bimodal AFM imaging on a two component polymer sample validate that the self-sensing scheme can therefore be used to provide both the feedback signal, for topography imaging on the fundamental mode, and phase imaging on the higher eigenmode.

2013 ◽  
Vol 84 (8) ◽  
pp. 083701 ◽  
Author(s):  
Eika Tsunemi ◽  
Kei Kobayashi ◽  
Noriaki Oyabu ◽  
Masaharu Hirose ◽  
Yoshiko Takenaka ◽  
...  

2007 ◽  
Vol 46 (8B) ◽  
pp. 5636-5638 ◽  
Author(s):  
Eika Tsunemi ◽  
Nobuo Satoh ◽  
Yuji Miyato ◽  
Kei Kobayashi ◽  
Kazumi Matsushige ◽  
...  

2021 ◽  
Author(s):  
Berkin Uluutku ◽  
Santiago D. Solares

Abstract Quantitative measurement of the probe-sample interaction forces as a function of distance and time during imaging has been at the forefront of atomic force microscopy (AFM) research. This type of information is extremely valuable for understanding the material response to a variety of stimuli and interactions, such as mechanical deformations that vary in magnitude and rate of application, chemical interactions, or electromagnetic interactions. A variety of methods for performing such measurements simultaneously with topographical imaging is available, including methods based on Fourier analysis. Within these methods, reconstruction of the tip-sample force curve generally requires measurement of a large number of harmonics of the probe oscillation, which presents challenges such as the need for specialized hardware, low signal-to-noise ratio, and the need for extensive user expertise. In this paper, we present a simple method to perform a Gaussian-model-based fit of the tip-sample force curve across the surface, simultaneously with imaging, which requires measurement of only the first two or three harmonics for elastic materials. While such an approach only offers an approximate representation of the force curve, it can be highly accurate and fast, and has low instrumentation requirements, such that it can be relatively simple to implement on most commercial AFM setups.


2015 ◽  
Vol 10 (1) ◽  
pp. 155892501501000
Author(s):  
Serpil Koral Koc

Potential applications of atomic force microscopy (AFM) in textiles are explained. For this purpose samples were carefully selected from both natural and synthetic fibers. Cotton, wool, conventional polyethylene terepthalate (PET), antibacterial PET, and antistatic PET were investigated by means of 3D topography imaging, phase imaging, and calculation of their Rq values. The distribution of the additives in the cross sections of antibacterial PET and antistatic PET were analyzed. Moreover, differences between inner and outer cross section of trilobal PET was observed by force spectroscopy. The results are discussed considering the fiber properties. It is concluded that AFM is a powerful tool to investigate different properties of textile fibers, and it gives valuable information.


1992 ◽  
Vol 72 (1) ◽  
pp. 6-12 ◽  
Author(s):  
Constant A. J. Putman ◽  
Bart G. De Grooth ◽  
Niek F. Van Hulst ◽  
Jan Greve

1997 ◽  
Vol 3 (S2) ◽  
pp. 1275-1276
Author(s):  
Sergei Magonov

Phase detection in TappingMode™ enhances capabilities of Atomic Force Microscopy (AFM) for soft samples (polymers and biological materials). Changes of amplitude and phase changes of a fast oscillating probe are caused by tip-sample force interactions. Height images reflect the amplitude changes, and in most cases they present a sample topography. Phase images show local differences between phases of free-oscillating probe and of probe interacting with a sample surface. These differences are related to the change of the resonance frequency of the probe either by attractive or repulsive tip-sample forces. Therefore phase detection helps to choose attractive or repulsive force regime for surface imaging and to minimize tip-sample force. For heterogeneous materials the phase imaging allows to distinguish individual components and to visualize their distribution due to differences in phase contrast. This is typically achieved in moderate tapping, when set-point amplitude, Asp, is about half of the amplitude of free-oscillating cantilever, Ao. In contrast, light tapping with Asp close to Ao is best suited for recording a true topography of the topmost surface layer of soft samples. Examples of phase imaging of polymers obtained with a scanning probe microscope Nanoscope® IIIa (Digital Instruments). Si probes (225 μk long, resonance frequencies 150-200 kHz) were used.


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