scholarly journals In Situ Laser-Induced Fabrication of a Ruthenium-Based Microelectrode for Non-Enzymatic Dopamine Sensing

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5385
Author(s):  
Maxim S. Panov ◽  
Anastasiia E. Grishankina ◽  
Daniil D. Stupin ◽  
Alexey I. Lihachev ◽  
Vladimir N. Mironov ◽  
...  

In this paper, we propose a fast and simple approach for the fabrication of the electrocatalytically active ruthenium-containing microstructures using a laser-induced metal deposition technique. The results of scanning electron microscopy and electrical impedance spectroscopy (EIS) demonstrate that the fabricated ruthenium-based microelectrode had a highly developed surface composed of 10 μm pores and 10 nm zigzag cracks. The fabricated material exhibited excellent electrochemical properties toward non-enzymatic dopamine sensing, including high sensitivity (858.5 and 509.1 μA mM−1 cm−2), a low detection limit (0.13 and 0.15 μM), as well as good selectivity and stability.

2015 ◽  
Vol 1120-1121 ◽  
pp. 572-575
Author(s):  
Hong Wei Liu ◽  
Feng Wang ◽  
Qiang Zhang ◽  
Xi Wu Li ◽  
Zhi Hui Li ◽  
...  

An innovative spray deposition technique has been applied to produce in situ TiB2/Zn-30Al-1Cu composites. The microstructures of the spray-deposited composite were studied using optical microscopy, scanning electron microscopy, and X-ray diffraction. Both theoretical and experimental results have shown that the TiB2particulates are formed in the microstructure. It was found that the TiB2particles were distributed in Zn-30Al-1Cu matrix uniformly, and the TiB2particles are about 2 μm in size. Moreover, the presence of the TiB2particles was led to increasing of α’ phase with less 2 μm size in the composites which have a tendency to decompose to α+η structure.


2018 ◽  
Author(s):  
Grigore Moldovan ◽  
Wolfgang Joachimi ◽  
Guillaume Boetsch ◽  
Jörg Jatzkowski ◽  
Frank Altman

Abstract This work presents advanced resistance mapping techniques based on Scanning Electron Microscopy (SEM) with nanoprobing systems and the related embedded electronics. Focus is placed on recent advances to reduce noise and increase speed, such as integration of dedicated in situ electronics into the nanoprobing platform, as well as an important transition from current-sensitive to voltagesensitive amplification. We show that it is now possible to record resistance maps with a resistance sensitivity in the 10W range, even when the total resistance of the mapped structures is in the range of 100W. A reference structure is used to illustrate the improved performance, and a lowresistance failure case is presented as an example of analysis made possible by these developments.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 446
Author(s):  
Ioannis Spanos ◽  
Zacharias Vangelatos ◽  
Costas Grigoropoulos ◽  
Maria Farsari

The need for control of the elastic properties of architected materials has been accentuated due to the advances in modelling and characterization. Among the plethora of unconventional mechanical responses, controlled anisotropy and auxeticity have been promulgated as a new avenue in bioengineering applications. This paper aims to delineate the mechanical performance of characteristic auxetic and anisotropic designs fabricated by multiphoton lithography. Through finite element analysis the distinct responses of representative topologies are conveyed. In addition, nanoindentation experiments observed in-situ through scanning electron microscopy enable the validation of the modeling and the observation of the anisotropic or auxetic phenomena. Our results herald how these categories of architected materials can be investigated at the microscale.


2020 ◽  
Vol 176 (1) ◽  
Author(s):  
W. D. Maier ◽  
S.-J. Barnes ◽  
D. Muir ◽  
D. Savard ◽  
Y. Lahaye ◽  
...  

AbstractBushveld anorthosites commonly contain the so-called “mottles” comprising irregular, typically centimetric domains of oikocrystic pyroxene or olivine enclosing small, embayed plagioclase grains. The mottles were traditionally interpreted to result from solidification of trapped intercumulus liquid or via in situ crystallisation at the top of the crystal mush. Here, we present microtextural and compositional data of a mottle to place further constraints on the formation of anorthosite layers. Element maps generated by scanning electron microscopy reveal that plagioclase within and around the mottle has markedly elevated An contents (up to An95) relative to the host anorthosite and is strongly reversely zoned. Other unusual features, some of which were reported previously, include a halo of sub-vertically oriented, acicular phlogopite around the mottle, elevated contents of disseminated sulfides, and relatively evolved yet Ni-rich olivine (Fo71–75, 3000 ppm Ni). These features are interpreted to result from reactive porous flow of hot, acidic fluid enriched in nickel and sulfur through proto norite. The fluids dissolved mafic minerals and leached alkalis from the outer rims of plagioclase grains. Reconnaissance studies suggest that reversed zoning of plagioclase is a common feature in Bushveld norite and anorthosite. This implies that reactive porous flow could have been far more pervasive than currently realised and that Bushveld anorthosite layers formed through recrystallisation of norites.


1991 ◽  
Vol 70 (4) ◽  
pp. 1544-1549 ◽  
Author(s):  
D. Negrini ◽  
S. Mukenge ◽  
M. Del Fabbro ◽  
C. Gonano ◽  
G. Miserocchi

In seven anesthetized rabbits we measured the size, shape, and density of lymphatic stomata on the peritoneal and pleural sides of the diaphragm. The diaphragm was fixed in situ and processed for scanning electron microscopy. Results are from 2,902 peritoneal and 3,086 pleural fields (each 1,620 microns 2) randomly chosen from the various specimens. Stomata were seen in 9% of the fields examined, and in 30% of the cases they appeared grouped in clusters with 2-14 stomata/field. Stoma density was 250 +/- 242 and 72 +/- 57 (SD) stomata/mm2 on peritoneal and pleural sides, respectively, and it was similar over the muscular and tendinous portion of the two surfaces. The maximum diameter ranged from less than 1 to approximately 30 microns, with an average value of 1.2 +/- 3.1 micron. The ratio of the maximum to the minimum diameter and the surface area averaged 2 +/- 1.4 and 0.7 +/- 2.4 micron 2, respectively. The maximum and minimum diameter and surface area values followed a lognormal frequency distribution, suggesting that stomata geometry is affected by diaphragmatic tension.


Sign in / Sign up

Export Citation Format

Share Document