Low Temperature Fabrication and Surface Modification Methods for Fused Silica Micro- and Nanochannels

2014 ◽  
Vol 1659 ◽  
pp. 15-26
Author(s):  
Sumita Pennathur ◽  
Pete Crisalli

ABSTRACTElectrokinetic based micro- and nanofluidic technologies provide revolutionary opportunities to separate, identify and analyze biomolecular species. Key to fully harnessing the power of such systems is the development of a robust method for integrated electrodes as well as a thorough understanding of the influence of the electrokinetic surface properties with and without different surface modifications. In this work, we demonstrate a surface micromachined fabrication approach for integrated addressable metal electrodes within centimeter-long nanofluidic channels using a low-temperature, xenon diflouride dry-release method for novel biosensing applications, as well as recent results from a joint theoretical and experimental study of electrokinetic surface properties in nano- and microfluidic channels fabricated with fused silica. The main contribution of this fabrication process involves the addition of addressable electrodes to a novel dry-release channel fabrication method, produced at <300°C, to be used in nanofluidic electronic sensing of biomolecules. Finally, we also show a novel method with which to coat our channels with silane based chemistries. Certain modifications are observed to show improved resistance to non-specific adhesion of both small molecules and proteins, indicating their further use as compatible surfaces in micro- and nanofluidic applications.

2020 ◽  
Vol 6 ◽  
pp. 40-55
Author(s):  
N.M. Ivanova ◽  
◽  
E.O. Filippova ◽  
A.N. Aleinik ◽  
V.F. Pichugin ◽  
...  

Effects of the low-temperature plasma exposure, γ-irradiation, and joint g-irradiation and plasma exposure on the structure and surface properties of thin films based on polylactic acid (PLA) have been investigated. Films were obtained by the method a solvent-casting. It has been shown that films based on polylactic acid have topographically different sides: a smoother inner side and embossed outer one. PLA films have properties close to those hydrophobic, with a contact angle in the range of 70°-73° regardless of the surface side and belong to a weakly polar materials. The combined effect of plasma and gamma radiation slightly changes the surface topography. The effect of low-temperature plasma on the surface of the films leads to a decrease in the contact angle by 13°-55° (9-11%) and an increase in surface energy due to the polar component. The results of in vivo experiments on rabbits are presented. Biomicroscopy, optical coherence tomography, morphological and electron microscopic examination of the cornea after implantation of initial and radiation and plasma treated films showed that implantation of the films in the anterior chamber is not accompanied by a pronounced inflammatory reaction and increased intraocular pressure, while maintaining the morphological structure of the cornea almost unchanged.


2016 ◽  
Vol 7 ◽  
pp. 767-775 ◽  
Author(s):  
Ayelet Ofarim ◽  
Bastian Kopp ◽  
Thomas Möller ◽  
León Martin ◽  
Johannes Boneberg ◽  
...  

We report the development of a novel method to determine the thermopower of atomic-sized gold contacts at low temperature. For these measurements a mechanically controllable break junction (MCBJ) system is used and a laser source generates a temperature difference of a few kelvins across the junction to create a thermo-voltage. Since the temperature difference enters directly into the Seebeck coefficient S = −ΔV/ΔT, the determination of the temperature plays an important role. We present a method for the determination of the temperature difference using a combination of a finite element simulation, which reveals the temperature distribution of the sample, and the measurement of the resistance change due to laser heating of sensor leads on both sides next to the junction. Our results for the measured thermopower are in agreement with recent reports in the literature.


RSC Advances ◽  
2020 ◽  
Vol 10 (66) ◽  
pp. 40047-40054
Author(s):  
Qizhi Chen ◽  
Yong Yang ◽  
Hang Luo ◽  
Zuohua Liu ◽  
Zhangfa Tong ◽  
...  

Ce modified MnOx/SAPO-34 was prepared and investigated for low-temperature selective catalytic reduction of NOx with ammonia (NH3-SCR).


2020 ◽  
Vol 29 (4) ◽  
pp. 2612-2622
Author(s):  
Yamid E. Núñez de la Rosa ◽  
Oriana Palma Calabokis ◽  
Paulo César Borges ◽  
Vladimir Ballesteros Ballesteros

1980 ◽  
Vol 37 (8) ◽  
pp. 394-397
Author(s):  
V. F. Sokolov ◽  
N. Yu. Komissarova ◽  
T. V. Sal'nikova

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mark MacKenzie ◽  
Haonan Chi ◽  
Manoj Varma ◽  
Parama Pal ◽  
Ajoy Kar ◽  
...  

AbstractWe report on an optimized fabrication protocol for obtaining silver nanoparticles on fused silica substrates via laser photoreduction of a silver salt solution. We find that multiple scans of the laser over the surface leads to a more uniform coverage of densely packed silver nanoparticles of approximately 50 nm diameter on the fused silica surface. Our substrates yield Raman enhancement factors of the order of 1011 of the signal detected from crystal violet. We use a theoretical model based on scanning electron microscope (SEM) images of our substrates to explain our experimental results. We also demonstrate how our technique can be extended to embedding silver nanoparticles in buried microfluidic channels in glass. The in situ laser inscription of silver nanoparticles on a laser machined, sub-surface, microfluidic channel wall within bulk glass paves the way for developing 3D, monolithic, fused silica surface enhance Raman spectroscopy (SERS) microfluidic sensing devices.


2016 ◽  
Vol 7 (5) ◽  
pp. 664-672 ◽  
Author(s):  
E. O. Filippova ◽  
D. A. Karpov ◽  
A. V. Gradoboev ◽  
V. V. Sokhoreva ◽  
V. F. Pichugin

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