Silicon Microarray Pin With Selective Hydrophobic Coating

2004 ◽  
Author(s):  
Jane Gin Fai Tsai ◽  
Chang-Jin Kim ◽  
Zugen Chen ◽  
Stanley Nelson
Keyword(s):  
Spot Size ◽  
Batch Processing ◽  
Surface Wettability ◽  
Serial Processing ◽  
Dramatic Effect ◽  
Interior Surface ◽  
Hydrophobic Coating ◽  
Array Density ◽  
First Time ◽  
Liquid Channel

We have recently demonstrated the viability of silicon microarray pins, taking advantage of lithographic and batch processing of silicon micromachining in comparison with conventional and serial processing currently used for commercial pins. The reduced spot size (< 50% in diameter, i.e., > 4X in array density), however, made such undesirable needs as preprinting more pronounced. Preprinting, a common practice in microarray printing, drains out the excess liquid formed outside the liquid channel during dipping. In this paper, we describe how surface wettability can be controlled and report its dramatic effect on the printing performance, for the first time. By making the exterior surfaces hydrophobic and the interior surface hydrophilic, the excess liquid outside the liquid channel is eliminated, and the advantages of silicon-micromachined pins are fully exercised.

Raman Spectra of Human Dental Calculus

1993 ◽  
Vol 72 (12) ◽  
pp. 1609-1613 ◽  
Author(s):  
H. Tsuda ◽  
J. Arends
Keyword(s):  
Raman Spectroscopy ◽  
Raman Spectra ◽  
Octacalcium Phosphate ◽  
Spot Size ◽  
Spectral Features ◽  
Dental Calculus ◽  
Micro Raman Spectroscopy ◽  
Vibrational Bands ◽  
First Time ◽  
Mineral Constituents

Raman spectra of human dental calculus have been observed for the first time by use of micro-Raman spectroscopy. The spectral features of calculus were influenced easily by heating caused by laser irradiation. Therefore, the measurements were carried out at relatively low power (5 mW, 1-μm spot size). The spectra could be characterized as phosphate vibrational bands due to the v1, v2, v 3, and v4 modes. The overall spectral features did not resemble those of pure minerals such as brushite, octacalcium phosphate, and hydroxyapatite. There were spectral differences among mixed calculus particles obtained from 18 adults, probably due to variations in local mineral composition and differences among patients. However, the averaged spectral features did not vary significantly with formation period from 1 to 6 months. Freshly removed and stored (5-11 months) calculus also gave comparable Raman spectra. Measurements on a fractured sample indicated that Raman spectra at saliva and dentin interfaces are nearly identical, and major mineral constituents may not vary significantly along the growth axis of calculus.

scholarly journals The Effect of Spot Size Combination Mode on Ablation Morphology of Aluminum Alloy by Millisecond-Nanosecond Combined-Pulse Laser

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1419 ◽  
Author(s):  
Bo-Shi Yuan ◽  
Ye Zhang ◽  
Wei Zhang ◽  
Yuan Dong ◽  
Guang-Yong Jin
Keyword(s):  
Aluminum Alloy ◽  
Laser Processing ◽  
Molten Pool ◽  
Physical Mechanism ◽  
Spot Size ◽  
Laser Spot ◽  
Nanosecond Laser ◽  
Combination Mode ◽  
First Time

Ablation morphology affects the quality of laser processing. Therefore, the control of ablation morphology is very important. The influence of spot size combination mode on the ablation morphology of aluminum alloy is studied for the first time. Experimental results show that when the nanosecond laser spot is larger, the ablation morphology looks like a bowl-shape, and there is little solidification near the edge. When the nanosecond laser spot is smaller, the shape of the ablation morphology is similar to a hole, and the protuberance is formed near the edge of the cavity. Through the analysis and simulation of the physical model, the physical mechanism, which describes the influence of the spot size combination mode on the molten pool, is discussed. The research results of this paper have important guiding significance for the control of laser processing effect.

Control of surface wettability for inkjet printing by combining hydrophobic coating and plasma treatment

2013 ◽  
Vol 546 ◽  
pp. 162-166 ◽  
Author(s):  
Heung Yeol Park ◽  
Byung Ju Kang ◽  
Dohyung Lee ◽  
Je Hoon Oh
Keyword(s):  
Plasma Treatment ◽  
Inkjet Printing ◽  
Surface Wettability ◽  
Hydrophobic Coating

Binary Optics Microlens Arrays in CdTe.

1990 ◽  
Vol 216 ◽  
Author(s):  
M.B. Stem ◽  
W.F. Delaney ◽  
M. Holz ◽  
K.P. Kunz ◽  
K.R. Maschhoff ◽  
...  
Keyword(s):  
Focal Plane ◽  
Ion Beam ◽  
Spot Size ◽  
Detector Plane ◽  
Optical Elements ◽  
Microlens Arrays ◽  
Ion Beam Etching ◽  
Binary Optics ◽  
Infrared Materials ◽  
First Time

ABSTRACTArrays of miniature focusing optics located at the focal plane can improve the performance of focal plane systems. By more completely collecting the light at the focal plane and concentrating it into a smaller spot size on the detector plane, the photodetector area can be substantially reduced. Increased gamma radiation hardening and noise reduction result from the decrease in photodetector surface area. Binary optics technology, a process for fabricating large arrays of diffractive optical elements, is especially attractive for infrared materials. In this paper, diffractive Fresnel microlens arrays containing over six thousand F/0.9 lenslets are patterned in the surface of CdTe substrates by successive photolithographic and Ar+ ion-beam-etching steps. Results on smaller arrays of monolithically integrated binary-optics lenslets with II-VI detectors, demonstrating enhanced photodetector responsivities, are presented for the first time.

scholarly journals Экспериментальное исследование влияния добавки наночастиц оксида кремния на характеристики смачиваемости нефтью горной породы

2020 ◽  
Vol 46 (24) ◽  
pp. 30
Author(s):  
А.В. Минаков ◽  
М.И. Пряжников ◽  
Я.Н. Сулемана ◽  
В.Д. Мешкова
Keyword(s):  
Interfacial Tension ◽  
Silicon Oxide ◽  
Experimental Studies ◽  
Wetting Angle ◽  
Surface Wettability ◽  
Oxide Nanoparticles ◽  
Rock System ◽  
Silicon Oxide Nanoparticles ◽  
First Time ◽  
Mass Concentrations

The results of experimental studies of interfacial tension and surface wettability in the nanoscale suspension/oil/rock system were presented. For the first time, the influence of the concentration and size of silicon oxide nanoparticles on the interfacial tension coefficient and the wetting angle was systematically studied. Wide ranges of nanoparticle mass concentrations(from 0 to 1wt.%)and their average sizes(from 5 to 50 nm) were considered. It is established that the use of nanosuspensions allows to radically change the wettability of rock with oil. This effect is significantly dependent on the concentration and size of nanoparticles.

PERFORMANCE OF A CDTE-BASED DIGITAL GAMMA IMAGING SYSTEM WITH A 75SE RADIOISOTOPE FOR NONDESTRUCTIVE TESTINGS

2008 ◽  
Vol 22 (11) ◽  
pp. 1045-1050
Author(s):  
H. S. CHO ◽  
S. I. CHOI ◽  
K. Y. KIM ◽  
J. E. OH ◽  
S. Y. LEE ◽  
...  
Keyword(s):  
Imaging System ◽  
Spot Size ◽  
Noise Power ◽  
Modulation Transfer ◽  
Operation Condition ◽  
X Ray ◽  
Gamma Imaging ◽  
X Ray Imaging ◽  
Imaging Performance ◽  
First Time

As a continuation of our digital radiographic sensor R&D, we have developed a digital gamma imaging system based upon the cadmium-telluride ( CdTe ) photoconductor for the applications of industrial gamma imaging. The imaging system consists of a commercially-available CMOS pixel array of a 100 × 100 μ m 2 pixel size and a 5.4 % 151.0 mm 2 active area, coupled with a 750-μm-thick CdTe photoconductor, and a collimated selenium (75 Se ) radioisotope of an about 62.8 Ci activity and a physical size of 3.0 mm in diameter. In this study, we, for the first time, succeeded in obtaining useful gamma images of several test phantoms with the 75 Se radioisotope from the imaging system and evaluated its imaging performance in terms of the modulation transfer function (MTF), the noise power spectrum (NPS), and the detective quantum efficiency (DQE). For comparison, we also tested its X-ray imaging performance with a microfocus X-ray tube of an about 5 μm focal spot size at an operation condition of 90 kVp and 100 μA.

Surface Modification Effect of Wettability on the Performance of PDMS-Based Valveless Micropump

2006 ◽  
Vol 326-328 ◽  
pp. 297-300 ◽  
Author(s):  
Woong Cho ◽  
Yong Jun Ko ◽  
Yoo Min Ahn ◽  
Joon Yong Yoon ◽  
Nahm Gyoo Cho
Keyword(s):  
Contact Angle ◽  
Surface Wettability ◽  
Poly Vinyl Alcohol ◽  
Membrane Pump ◽  
Pdms Surface ◽  
Hydrophobic Coating ◽  
Valveless Micropump ◽  
Priming Process ◽  
Coated Surface ◽  
Effect Of Surface

Experimental investigation and numerical simulation on the effect of surface wettability on the performance of a polydimethylsiloxane (PDMS) based diffuser micropump are presented. A valveless micro membrane pump with piezoelectric actuation has been examined. Using a replica molding technique, the valveless micropump was made of PDMS on a Pyrex glass substrate. A thin piezoelectric (PZT) disc was used as an actuator. Poly vinyl alcohol (PVA) and octadecyltrichlorosilane (OTS) coatings, which make the coated surface hydrophilic and hydrophobic, respectively, were used to modify the surface wettability inside the pump. In our experiments, the contact angle of the PDMS surface changed from 96.6 o to 29.1 o and 99.6 o by PVA and OTS coatings, respectively, and the contact angle of glass changed from 33.2 o to 17.5 o and 141.8 o. A self-priming process was numerically simulated in a diffuser element using a computational fluid dynamics program (CFD-ACE+). The results show that fewer gas bubbles were created in the hydrophilic coated pump than in the hydrophobic coated one as time progressed. This agrees well with experimental observations. Steady-state flow rates of the micropump were measured. Compared to the non-coated pump, the flow rate increased slightly with the hydrophobic coating but decreased with the hydrophilic coating. We determine that surface wettability significantly affects the performance of a PDMS-based micropump.

Remarks on the application of backscattered electron imaging (BEI) to the scanning electron microscopy (SEM) of biological structures

1983 ◽  
Vol 41 ◽  
pp. 484-487
Author(s):  
Etienne de Harven
Keyword(s):  
High Resolution ◽  
Incident Beam ◽  
Spot Size ◽  
Primary Electron ◽  
Critical Point Drying ◽  
Cell Shapes ◽  
High Resolution Images ◽  
Backscattered Electron ◽  
Electron Imaging ◽  
Scanning Electron

Biological ultrastructures have been extensively studied with the scanning electron microscope (SEM) for the past 12 years mainly because this instrument offers accurate and reproducible high resolution images of cell shapes, provided the cells are dried in ways which will spare them the damage which would be caused by air drying. This can be achieved by several techniques among which the critical point drying technique of T. Anderson has been, by far, the most reproducibly successful. Many biologists, however, have been interpreting SEM micrographs in terms of an exclusive secondary electron imaging (SEI) process in which the resolution is primarily limited by the spot size of the primary incident beam. in fact, this is not the case since it appears that high resolution, even on uncoated samples, is probably compromised by the emission of secondary electrons of much more complex origin.When an incident primary electron beam interacts with the surface of most biological samples, a large percentage of the electrons penetrate below the surface of the exposed cells.

Annulate lamellae in the Sertoli cells of guinea pig testis after unilateral torsion of the spermatic cord

1984 ◽  
Vol 42 ◽  
pp. 196-197
Author(s):  
J. Chakraborty ◽  
A. P. Sinha Hikim ◽  
J. S. Jhunjhunwala
Keyword(s):  
Sertoli Cells ◽  
Guinea Pigs ◽  
Spermatic Cord ◽  
Present Report ◽  
Cell Types ◽  
Annulate Lamellae ◽  
Spermatogenic Cells ◽  
Electron Microscopic ◽  
Structural Details ◽  
First Time

Although the presence of annulate lamellae was noted in many cell types, including the rat spermatogenic cells, this structure was never reported in the Sertoli cells of any rodent species. The present report is based on a part of our project on the effect of torsion of the spermatic cord to the contralateral testis. This paper describes for the first time, the fine structural details of the annulate lamellae in the Sertoli cells of damaged testis from guinea pigs.One side of the spermatic cord of each of six Hartly strain adult guinea pigs was surgically twisted (540°) under pentobarbital anesthesia (1). Four months after induction of torsion, animals were sacrificed, testes were excised and processed for the light and electron microscopic investigations. In the damaged testis, the majority of seminiferous tubule contained a layer of Sertoli cells with occasional spermatogonia (Fig. 1). Nuclei of these Sertoli cells were highly pleomorphic and contained small chromatinic clumps adjacent to the inner aspect of the nuclear envelope (Fig. 2).

Sign in / Sign up

Export Citation Format

Share Document