scholarly journals Lights Out! Nano-Scale Topography Imaging of Sample Surface in Opaque Liquid Environments with Coated Active Cantilever Probes

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 1013 ◽  
Author(s):  
Fangzhou Xia ◽  
Chen Yang ◽  
Yi Wang ◽  
Kamal Youcef-Toumi ◽  
Christoph Reuter ◽  
...  
Keyword(s):  
Polymer Surface ◽  
Sample Surface ◽  
Laser Source ◽  
Piezo Actuator ◽  
Imaging Method ◽  
Lever System ◽  
Atomic Force ◽  
Cantilever Probes ◽  
Optical Lever ◽  
Four Quadrant

Atomic force microscopy is a powerful topography imaging method used widely in nanoscale metrology and manipulation. A conventional Atomic Force Microscope (AFM) utilizes an optical lever system typically composed of a laser source, lenses and a four quadrant photodetector to amplify and measure the deflection of the cantilever probe. This optical method for deflection sensing limits the capability of AFM to obtaining images in transparent environments only. In addition, tapping mode imaging in liquid environments with transparent sample chamber can be difficult for laser-probe alignment due to multiple different refraction indices of materials. Spurious structure resonance can be excited from piezo actuator excitation. Photothermal actuation resolves the resonance confusion but makes optical setup more complicated. In this paper, we present the design and fabrication method of coated active scanning probes with piezoresistive deflection sensing, thermomechanical actuation and thin photoresist polymer surface coating. The newly developed probes are capable of conducting topography imaging in opaque liquids without the need of an optical system. The selected coating can withstand harsh chemical environments with high acidity (e.g., 35% sulfuric acid). The probes are operated in various opaque liquid environments with a custom designed AFM system to demonstrate the imaging performance. The development of coated active probes opens up possibilities for observing samples in their native environments.

Wrinkling Poly(trimethylene 2,5-Furanoate) Free-standing Films: Nanostructure Formation and Physical Properties

2020 ◽  
Author(s):  
Michelina Soccio ◽  
Nadia Lotti ◽  
Andrea Munari ◽  
Esther Rebollar ◽  
Daniel E Martínez-Tong
Keyword(s):  
Irradiation Time ◽  
Polymer Surface ◽  
Laser Source ◽  
Free Standing ◽  
Force Microscopy ◽  
Nanostructure Formation ◽  
Physicochemical Changes ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements

<p>Nanostructured wrinkles were developed on fully bio-based poly(trimethylene furanoate) (PTF) films by using the technique of Laser Induced Periodic Surface Structures (LIPSS). We investigated the effect of irradiation time on wrinkle formation using an UV pulsed laser source, at a fluence of 8 mJ/cm2. It was found that the pulse range between 600 and 4800 pulses allowed formation of periodic nanometric ripples. The nanostructured surface was studied using a combined macro- and nanoscale approach. We evaluated possible physicochemical changes taking place on the polymer surface after irradiation by infrared spectroscopy, contact angle measurements and atomic force microscopy. The macroscopic physicochemical properties of PTF showed almost no changes after nanostructure formation, differently from the results previously found for the terephthalic counterparts, as poly(ethyleneterephthalate), PET, and poly(trimethyleneterephthalate), PTT. The surface mechanical properties of the nanostructured PTF were found to be improved, as evidenced by nanomechanical force spectroscopy measurements. In particular, an increased Young’s modulus and higher stiffness for the nanostructured sample were measured. <br></p>

The scanning ion conductance microscope for cellular physiology

2013 ◽  
Vol 304 (1) ◽  
pp. H1-H11 ◽  
Author(s):  
Max J. Lab ◽  
Anamika Bhargava ◽  
Peter T. Wright ◽  
Julia Gorelik
Keyword(s):  
Feedback Control ◽  
Biological Samples ◽  
Three Dimensional ◽  
Sample Surface ◽  
Piezo Actuator ◽  
Ion Conductance ◽  
Functional Capabilities ◽  
Atomic Force ◽  
Pipette Tip ◽  
Near Future

The quest for nonoptical imaging methods that can surmount light diffraction limits resulted in the development of scanning probe microscopes. However, most of the existing methods are not quite suitable for studying biological samples. The scanning ion conductance microscope (SICM) bridges the gap between the resolution capabilities of atomic force microscope and scanning electron microscope and functional capabilities of conventional light microscope. A nanopipette mounted on a three-axis piezo-actuator, scans a sample of interest and ion current is measured between the pipette tip and the sample. The feedback control system always keeps a certain distance between the sample and the pipette so the pipette never touches the sample. At the same time pipette movement is recorded and this generates a three-dimensional topographical image of the sample surface. SICM represents an alternative to conventional high-resolution microscopy, especially in imaging topography of live biological samples. In addition, the nanopipette probe provides a host of added modalities, for example using the same pipette and feedback control for efficient approach and seal with the cell membrane for ion channel recording. SICM can be combined in one instrument with optical and fluorescent methods and allows drawing structure-function correlations. It can also be used for precise mechanical force measurements as well as vehicle to apply pressure with precision. This can be done on living cells and tissues for prolonged periods of time without them loosing viability. The SICM is a multifunctional instrument, and it is maturing rapidly and will open even more possibilities in the near future.

Wrinkling Poly(trimethylene 2,5-Furanoate) Free-standing Films: Nanostructure Formation and Physical Properties

2020 ◽  
Author(s):  
Michelina Soccio ◽  
Nadia Lotti ◽  
Andrea Munari ◽  
Esther Rebollar ◽  
Daniel E Martínez-Tong
Keyword(s):  
Irradiation Time ◽  
Polymer Surface ◽  
Laser Source ◽  
Free Standing ◽  
Force Microscopy ◽  
Nanostructure Formation ◽  
Physicochemical Changes ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements

<p>Nanostructured wrinkles were developed on fully bio-based poly(trimethylene furanoate) (PTF) films by using the technique of Laser Induced Periodic Surface Structures (LIPSS). We investigated the effect of irradiation time on wrinkle formation using an UV pulsed laser source, at a fluence of 8 mJ/cm2. It was found that the pulse range between 600 and 4800 pulses allowed formation of periodic nanometric ripples. The nanostructured surface was studied using a combined macro- and nanoscale approach. We evaluated possible physicochemical changes taking place on the polymer surface after irradiation by infrared spectroscopy, contact angle measurements and atomic force microscopy. The macroscopic physicochemical properties of PTF showed almost no changes after nanostructure formation, differently from the results previously found for the terephthalic counterparts, as poly(ethyleneterephthalate), PET, and poly(trimethyleneterephthalate), PTT. The surface mechanical properties of the nanostructured PTF were found to be improved, as evidenced by nanomechanical force spectroscopy measurements. In particular, an increased Young’s modulus and higher stiffness for the nanostructured sample were measured. <br></p>

Imaging polymers, proteins and dna in aqueous solutions with the atomic force microscope

1989 ◽  
Vol 47 ◽  
pp. 32-33
Author(s):  
S.A.C. Gould ◽  
B. Drake ◽  
C.B. Prater ◽  
A.L. Weisenhorn ◽  
S.M. Lindsay ◽  
...  
Keyword(s):  
Amino Acids ◽  
Dna Sequencing ◽  
Aqueous Solutions ◽  
Atomic Force Microscope ◽  
Piezoelectric Crystal ◽  
Atomic Force ◽  
Structure Of Molecules ◽  
Optical Lever

The atomic force microscope (AFM) is an instrument that can be used to image many samples of interest in biology and medicine. Images of polymerized amino acids, polyalanine and polyphenylalanine demonstrate the potential of the AFM for revealing the structure of molecules. Images of the protein fibrinogen which agree with TEM images demonstrate that the AFM can provide topographical data on larger molecules. Finally, images of DNA suggest the AFM may soon provide an easier and faster technique for DNA sequencing.The AFM consists of a microfabricated SiO2 triangular shaped cantilever with a diamond tip affixed at the elbow to act as a probe. The sample is mounted on a electronically driven piezoelectric crystal. It is then placed in contact with the tip and scanned. The topography of the surface causes minute deflections in the 100 μm long cantilever which are detected using an optical lever.

A new, optical‐lever based atomic force microscope

1994 ◽  
Vol 76 (2) ◽  
pp. 796-799 ◽  
Author(s):  
P. K. Hansma ◽  
B. Drake ◽  
D. Grigg ◽  
C. B. Prater ◽  
F. Yashar ◽  
...  
Keyword(s):  
Atomic Force Microscope ◽  
Atomic Force ◽  
Optical Lever

scholarly journals Assessment of disc brake vibration in rail vehicle operation on the basis of brake stand

2021 ◽  
Vol 23 (2) ◽  
pp. 221-230
Author(s):  
Wojciech Sawczuk ◽  
Agnieszka Merkisz-Guranowska ◽  
Armando-Miguel Rilo Cañás
Keyword(s):  
Mass Distribution ◽  
System Component ◽  
Brake Disc ◽  
Imaging Method ◽  
Disc Brake ◽  
Lever System ◽  
Vehicle Operation ◽  
Lever Mechanism ◽  
The Right ◽  
Vibroacoustic Signals

The scientific aim of the article is to present the relationship between the vibroacoustic signals of the right and left friction pad during braking, depending on the mass distribution, as an element of the lever system. This article presents the results of tests of a railway disc brake in the scope of vibrations generated by pads in various states of wear located on both sides of the brake disc. The tests were carried out on the brake stand using the vibroacoustic method including the analysis of amplitudes and frequencies and the thermal imaging method. Special attention was paid to the analysis of the classic lever mechanism as a multimass system influencing the thermo-mechanical characteristics and vibrations of the pads on the right and left side of the brake disc. Uneven mass distribution of the system translates into uneven wear of the friction components. The scientific aim of this paper is to present the relation between vibroacoustic signals of the right and left friction pad during braking depending on the mass distribution of the lever system component.

Profile Measurement by Using a Femtosecond Laser Chromatic Confocal Probe

2020 ◽  
Author(s):  
Ryo Sato ◽  
Yuki Shimizu ◽  
Hiraku Matsukuma ◽  
Wei Gao
Keyword(s):  
Thermal Stability ◽  
Femtosecond Laser ◽  
Surface Profile ◽  
Sample Surface ◽  
Measurement Range ◽  
Laser Source ◽  
Profile Measurement ◽  
Experimental Setup ◽  
Chromatic Confocal Probe ◽  
Surface Profile Measurement

Abstract Confocal probes are widely employed in many industrial fields due to the depth-sectioning effect. The author’s group has also proposed a chromatic confocal probe employing a mode-locked femtosecond laser source which can realize an axial resolution of 30 nm and a measurement range of 40 μm Efforts have also been made to improve the thermal stability of the developed femtosecond laser chromatic confocal probe so that the probe can be applied for long-term displacement measurement or surface profile measurement. Meanwhile, surface profile measurement has not been carried out by using the developed femtosecond laser chromatic confocal probe. For the verification of the performance of developed probe in profile measurement, in this paper, an experimental setup is built and a basic experiment is carried out. By using the probe with further improved thermal stability, the measurement of a sample surface profile is carried out. In this paper, the development of the experimental setup with the femtosecond laser chromatic confocal probe, as well as the results of the surface profile measurements, is presented.

The Relation of Muscular Tonus and the Patellar Reflex to Mental Work

1929 ◽  
Vol 75 (309) ◽  
pp. 234-241 ◽  
Author(s):  
F. L. Golla ◽  
S. Antonovitch
Keyword(s):  
Mental Work ◽  
Intellectual Work ◽  
Lever System ◽  
Optical Lever ◽  
Slight Displacement

The fact that intellectual effort is accompanied by an increase of muscular tonus was demonstrated by one of us in 1921 (1), the method employed being the registration, by means of a highly magnifying optical lever system, of slight displacement of a relaxed limb. It was found that those muscles which were in a state of postural tension increased in tonus during intellectual work, whilst the fully relaxed antagonists remained unaffected.

Characterization of Multi-Phase and Multi-Component Polymer Systems Using the Atomic Force Microscope

1999 ◽  
Vol 5 (S2) ◽  
pp. 962-963
Author(s):  
M. VanLandingham ◽  
X. Gu ◽  
D. Raghavan ◽  
T. Nguyen
Keyword(s):  
Energy Dissipation ◽  
Atomic Force Microscope ◽  
Mechanical Response ◽  
Sample Surface ◽  
Phase Changes ◽  
Phase Imaging ◽  
Polymer Systems ◽  
Atomic Force ◽  
Phase Images ◽  
Multi Phase

Recent advances have been made on two fronts regarding the capability of the atomic force microscope (AFM) to characterize the mechanical response of polymers. Phase imaging with the AFM has emerged as a powerful technique, providing contrast enhancement of topographic features in some cases and, in other cases, revealing heterogeneities in the polymer microstructure that are not apparent from the topographic image. The enhanced contrast provided by phase images often allows for identification of different material constituents. However, while the phase changes of the oscillating probe are associated with energy dissipation between the probe tip and the sample surface, the relationship between this energy dissipation and the sample properties is not well understood.As the popularity of phase imaging has grown, the capability of the AFM to measure nanoscale indentation response of polymers has also been explored. Both techniques are ideal for the evaluation of multi-phase and multi-component polymer systems.

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