scholarly journals Two-step hybrid process of movable part inside glass substrate using ultrafast laser

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jeongtae Kim ◽  
Sung-Il Kim ◽  
Yeun-Ho Joung ◽  
Jiyeon Choi ◽  
Chiwan Koo

AbstractWe demonstrate a two-step hybrid process for fabricating movable parts inside glass substrate using the selective laser-induced etching (SLE) process that is consisted of laser-direct writing and wet chemical etching. To obtain an influence by the optical characteristics of a glass substrate when fabricating a 3D microstructure using the SLE, we analyzed the relationship of their dimensions between the designed and the fabricated devices. Two 3D microfluidic devices are designed and fabricated on glass substrates as the demonstrations of the hybrid process: a 3D microfluidic valve device with a movable plug and a 3D microfluidic mixer with a rotatable impeller and multilayer microchannels. The valving plug and the impeller of each device are successfully moved and rotated. The smallest structure is a pillar of the impeller device, and its size is 29 μm (diameter) × 277 μm (height). We expect this study to be extended to potential applications in 3D glass microfabrication and microfluidic systems.

1990 ◽  
Vol 01 (03n04) ◽  
pp. 303-345 ◽  
Author(s):  
ALEXANDER M. VOSHCHENKOV

Over the past decade, as the rapid evolution of semiconductor technology has progressed towards submicron design rules, plasma (dry) etching has supplanted simple wet etching processes for the transfer of patterns. To understand the underlying need for development of plasma etching, a brief background of integrated semiconductor technology is presented. Along with a historical perspective of the evolution of plasma etching, the relationship of plasma etching to lithography needs, its basic characteristics and advantages over wet chemical processing are discussed. Following this, relevant concepts of plasma physics and chemistry, based on experience with plasma etching applications for silicon technology, which can be used as building blocks for technology development are described.


2011 ◽  
Vol 291-294 ◽  
pp. 1373-1376
Author(s):  
Yi Gui Li ◽  
Jing Quan Liu ◽  
Chun Sheng Yang ◽  
Dan Nong He ◽  
Katsuhiko Tanaka ◽  
...  

The PZT is used for piezoelectric actuators that have high area efficiency but no good machinability. A direct writing micro structures on PZT wafer by excimer laser micromaching method has been proposed and confirmed. PZT nano-needle structures have also been fabricated by the direct writing method only by changing the laser micromachiong process parameters. The fabricated nano-needle structures can be very useful because of the need for studies on ferroelectric size effects as well as for potential applications such as ultra-high density memory devices.The relationship of process depth with the excimer laser parameters has been tested.


2020 ◽  
Vol 2 (1) ◽  
pp. 14-27
Author(s):  
Christoph Metzner ◽  
Marianne Zaruba

A broad definition of extracellular vesicles – lipid membrane enclosed vesicles of a given size range, produced by cells into the surrounding media and unable to replicate independently – does not only apply to exosomes or microvesicles produced by eukaryotic cells, outer membrane or outer-inner membrane vesicles produced by gram-negative bacteria and membrane vesicles produced by gram-positive bacteria (and archaea), but also extends to enveloped virus particles. They share biophysical and biochemical characteristics as well as functional properties, making it a challenge to distinguish between types of vesicles. In this review, we will briefly introduce different extracellular vesicles before concentrating on the relationship of viral particles to extracellular vesicles, taking practical issues into consideration as well as molecular interactions and the subsequent effects on infectivity and pathogenesis. Finally, we will briefly discuss potential applications of the relationship between extracellular vesicles and viral particles.


2022 ◽  
Vol 16 (1) ◽  
pp. 52-59
Author(s):  
Michio Uneda ◽  
Nodoka Yamada ◽  
Yoshihiro Tawara ◽  
◽  

Chemical mechanical polishing (CMP) using a suede polishing pad is an essential fabrication process for glass substrates that require ultra-high planarization. However, the effect of surface asperities of the suede pad on its polishing characteristics is not completely understood because the structure of the suede pad in the thickness direction is not constant, and its surface asperities can easily change during the pad conditioning or marathon polishing processes. In addition, many previous studies have discussed the polishing mechanism using a suede pad; however, these studies used suede pads with a pore size of approximately 100 μm. This paper discusses the polishing characteristics of a suede pad with fine micrometer-sized pores by clarifying the relationships between the removal rate, friction coefficient, pore parameters, and roughness as the pad surface asperities. In this study, a series of marathon polishing tests were performed with and without conditioning. It was discovered that the removal rate was affected not only by the pore parameters but also by the surface roughness of the suede pad with fine pores. The relationship between the removal rate and the friction coefficient changed owing to the influence of pad conditioning, and this change is significant when the break-in conditioning time is short.


Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.


Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.


Author(s):  
Leon Dmochowski

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.


Author(s):  
J.R. Pfeiffer ◽  
J.C. Seagrave ◽  
C. Wofsy ◽  
J.M. Oliver

In RBL-2H3 rat leukemic mast cells, crosslinking IgE-receptor complexes with anti-IgE antibody leads to degranulation. Receptor crosslinking also stimulates the redistribution of receptors on the cell surface, a process that can be observed by labeling the anti-IgE with 15 nm protein A-gold particles as described in Stump et al. (1989), followed by back-scattered electron imaging (BEI) in the scanning electron microscope. We report that anti-IgE binding stimulates the redistribution of IgE-receptor complexes at 37“C from a dispersed topography (singlets and doublets; S/D) to distributions dominated sequentially by short chains, small clusters and large aggregates of crosslinked receptors. These patterns can be observed (Figure 1), quantified (Figure 2) and analyzed statistically. Cells incubated with 1 μg/ml anti-IgE, a concentration that stimulates maximum net secretion, redistribute receptors as far as chains and small clusters during a 15 min incubation period. At 3 and 10 μg/ml anti-IgE, net secretion is reduced and the majority of receptors redistribute rapidly into clusters and large aggregates.


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