High Sensitivity of Dry-Type Nanowire Sensors With High- $k$ Dielectrics for pH Detection via Capillary Atomic Force Microscope Tip Coating Technique

2012 ◽  
Vol 33 (9) ◽  
pp. 1312-1314 ◽  
Author(s):  
Huang-Chung Cheng ◽  
Chun-Yu Wu ◽  
Po-Yen Hsu ◽  
Chao-Lung Wang ◽  
Ta-Chuan Liao ◽  
...  
Keyword(s):  
Atomic Force Microscope ◽  
High Sensitivity ◽  
Coating Technique ◽  
Atomic Force ◽  
High K ◽  
Ph Detection ◽  
Nanowire Sensors

scholarly journals Nanopipette/Nanorod-Combined Quartz Tuning Fork–Atomic Force Microscope

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1794 ◽  
Author(s):  
Sangmin An ◽  
Wonho Jhe
Keyword(s):  
Atomic Force Microscope ◽  
Tuning Fork ◽  
High Sensitivity ◽  
Quartz Tuning Fork ◽  
Force Sensor ◽  
Au Nanoparticle ◽  
Ambient Conditions ◽  
Atomic Force ◽  
In Situ Detection

We introduce a nanopipette/quartz tuning fork (QTF)–atomic force microscope (AFM) for nanolithography and a nanorod/QTF–AFM for nanoscratching with in situ detection of shear dynamics during performance. Capillary-condensed nanoscale water meniscus-mediated and electric field-assisted small-volume liquid ejection and nanolithography in ambient conditions are performed at a low bias voltage (~10 V) via a nanopipette/QTF–AFM. We produce and analyze Au nanoparticle-aggregated nanowire by using nanomeniscus-based particle stacking via a nanopipette/QTF–AFM. In addition, we perform a nanoscratching technique using in situ detection of the mechanical interactions of shear dynamics via a nanorod/QTF–AFM with force sensor capability and high sensitivity.

Quantifying Attractor Morphing for High-Sensitivity Detection of Parameter Variations by Point Cloud Averaging

2005 ◽  
Author(s):  
Ali I. Hashmi ◽  
Bogdan I. Epureanu
Keyword(s):  
Atomic Force Microscope ◽  
Point Cloud ◽  
Time Series Data ◽  
Equations Of Motion ◽  
High Sensitivity ◽  
Series Data ◽  
Optimal Basis ◽  
Atomic Force ◽  
Nominal Parameter ◽  
Parameter Values

A novel method of damage detection for systems exhibiting chaotic dynamics is presented. The algorithm reconstructs variations of system parameters without the need for explicit system equations of motion, or knowledge of the nominal parameter values. The concept of a Sensitivity Vector Field (SVF) is developed. This construct captures geometrical deformations of the dynamical attractor of the system in state space. These fields are collected by the means of Point Cloud Averaging (PCA) applied to discrete time series data from the system under healthy (nominal parameter values) and damaged (variations of the parameters) conditions. Test variations are reconstructed from an optimal basis of the SVF snapshots which is generated by means of proper orthogonal decomposition. The method is applied to two system models, a magneto-elastic oscillator and an atomic force microscope. The method is shown to be highly accurate, and capable of identifying multiple simultaneous variations. The success of the method as applied to an atomic force microscope (AFM) and a magneto-elastic oscillator (MEO) indicates a potential for highly accurate sample readings by exploiting recently observed chaotic vibrations.

Quantitative, Nanoscale Free-Carrier Concentration Mapping Using Terahertz Nearfield Nanoscopy

2010 ◽  
Author(s):  
J. Wittborn ◽  
R. Weiland ◽  
A. J. Huber ◽  
F. Keilmann ◽  
R. Hillenbrand
Keyword(s):  
Atomic Force Microscope ◽  
Carrier Concentration ◽  
Spatial Resolution ◽  
Near Field ◽  
High Sensitivity ◽  
Free Carrier ◽  
Atomic Force ◽  
Mobile Carrier ◽  
Field Excitation ◽  
Concentration Mapping

Abstract We use ultra-resolving terahertz (THz) near-field microscopy based on THz scattering at atomic force microscope tips to analyze 65-nm technology node transistors. Nanoscale resolution is achieved by THz field confinement at the very tip apex to within 30 nm. Images of semiconductor transistors provide evidence of 40 nm (λ/3000) spatial resolution at 2.54 THz (wavelength λ = 118µm) and demonstrate the simultaneous THz recognition of materials and mobile carriers in a single nanodevice. The mobile carrier contrast can be clearly related to near-field excitation of THz-plasmons in the semiconductor regions. The extraordinary high sensitivity of our microscope provides THz near-field contrasts from less then 100 mobile electrons in the probed volume.

Characterization of photosystem II with the atomic-force microscope

1992 ◽  
Vol 50 (2) ◽  
pp. 1146-1147
Author(s):  
Kathleen M. Marr ◽  
Mary K. Lyon
Keyword(s):  
Photosystem Ii ◽  
Atomic Force Microscope ◽  
Three Dimensional ◽  
Biologically Active ◽  
Atomic Force ◽  
Freeze Etching ◽  
Image Averaging ◽  
Oxygen Evolving ◽  
Averaging Techniques

Photosystem II (PSII) is different from all other reaction centers in that it splits water to evolve oxygen and hydrogen ions. This unique ability to evolve oxygen is partly due to three oxygen evolving polypeptides (OEPs) associated with the PSII complex. Freeze etching on grana derived insideout membranes revealed that the OEPs contribute to the observed tetrameric nature of the PSIl particle; when the OEPs are removed, a distinct dimer emerges. Thus, the surface of the PSII complex changes dramatically upon removal of these polypeptides. The atomic force microscope (AFM) is ideal for examining surface topography. The instrument provides a topographical view of individual PSII complexes, giving relatively high resolution three-dimensional information without image averaging techniques. In addition, the use of a fluid cell allows a biologically active sample to be maintained under fully hydrated and physiologically buffered conditions. The OEPs associated with PSII may be sequentially removed, thereby changing the surface of the complex by one polypeptide at a time.

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.

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