scholarly journals Liquid repellency enhancement through flexible microstructures

2020 ◽  
Vol 6 (32) ◽  
pp. eaba9721 ◽  
Author(s):  
Songtao Hu ◽  
Xiaobao Cao ◽  
Tom Reddyhoff ◽  
Debashis Puhan ◽  
Sorin-Cristian Vladescu ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Type System ◽  
Laser Lithography ◽  
Topological Features ◽  
Mechanical Metamaterials ◽  
Direct Laser ◽  
Flexible Supports ◽  
Recent Developments ◽  
Liquid Repellency

Artificial liquid-repellent surfaces have attracted substantial scientific and industrial attention with a focus on creating functional topological features; however, the role of the underlying structures has been overlooked. Recent developments in micro-nanofabrication allow us now to construct a skin-muscle type system combining interfacial liquid repellence atop a mechanically functional structure. Specifically, we design surfaces comprising bioinspired, mushroom-like repelling heads and spring-like flexible supports, which are realized by three-dimensional direct laser lithography. The flexible supports elevate liquid repellency by resisting droplet impalement and reducing contact time. This, previously unknown, use of spring-like flexible supports to enhance liquid repellency provides an excellent level of control over droplet manipulation. Moreover, this extends repellent microstructure research from statics to dynamics and is envisioned to yield functionalities and possibilities by linking functional surfaces and mechanical metamaterials.

Three-Dimensional Soft Material Micropatterning via Direct Laser Lithography of Flexible Molds

2016 ◽  
Vol 8 (38) ◽  
pp. 25019-25023 ◽  
Author(s):  
Irene Bernardeschi ◽  
Omar Tricinci ◽  
Virgilio Mattoli ◽  
Carlo Filippeschi ◽  
Barbara Mazzolai ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Soft Material ◽  
Laser Lithography ◽  
Direct Laser

Formation of Fe—Cu metal parts using direct laser sintering

2003 ◽  
Vol 217 (1) ◽  
pp. 139-147 ◽  
Author(s):  
H H Zhu ◽  
J Y H Fuh ◽  
L Lu
Keyword(s):  
Surface Roughness ◽  
Three Dimensional ◽  
Laser Sintering ◽  
Sintering Process ◽  
Metal Parts ◽  
Direct Laser ◽  
Scan Speed ◽  
Part Distortion ◽  
Metallic Parts

The direct laser sintering process is currently being used to manufacture metallic parts for prototyping and tooling directly. This paper reports on the direct laser sintering of Fe—Cu metal powder using a 200 W CO2 laser. The effects of the ratio of Fe to Cu, the scan speed and atmosphere on the distortion, surface morphology and surface roughness have been investigated. The experiment also investigated the role of adding W particles to the Fe—Cu mixture. The result shows that adding W particles can reduce part distortion. To find the effect of gas protection in laser sintering, the three-dimensional specimens fabricated in both air and N2 atmosphere are also compared.

scholarly journals Micro-/Nanorobots Propelled by Oscillating Magnetic Fields

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 540 ◽  
Author(s):  
Hao Yu ◽  
Wentian Tang ◽  
Guanyu Mu ◽  
Haocheng Wang ◽  
Xiaocong Chang ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Self Assembly ◽  
Environmental Remediation ◽  
Three Dimensional ◽  
Electron Beam Evaporation ◽  
Summary Table ◽  
Continuous Innovation ◽  
Direct Laser ◽  
Recent Developments ◽  
Long Lifetime

Recent strides in micro- and nanomanufacturing technologies have sparked the development of micro-/nanorobots with enhanced power and functionality. Due to the advantages of on-demand motion control, long lifetime, and great biocompatibility, magnetic propelled micro-/nanorobots have exhibited considerable promise in the fields of drug delivery, biosensing, bioimaging, and environmental remediation. The magnetic fields which provide energy for propulsion can be categorized into rotating and oscillating magnetic fields. In this review, recent developments in oscillating magnetic propelled micro-/nanorobot fabrication techniques (such as electrodeposition, self-assembly, electron beam evaporation, and three-dimensional (3D) direct laser writing) are summarized. The motion mechanism of oscillating magnetic propelled micro-/nanorobots are also discussed, including wagging propulsion, surface walker propulsion, and scallop propulsion. With continuous innovation, micro-/nanorobots can become a promising candidate for future applications in the biomedical field. As a step toward designing and building such micro-/nanorobots, several types of common fabrication techniques are briefly introduced. Then, we focus on three propulsion mechanisms of micro-/nanorobots in oscillation magnetic fields: (1) wagging propulsion; (2) surface walker; and (3) scallop propulsion. Finally, a summary table is provided to compare the abilities of different micro-/nanorobots driven by oscillating magnetic fields.

Vacancies for controlling the behavior of microstructured three-dimensional mechanical metamaterials

2018 ◽  
Vol 24 (2) ◽  
pp. 511-524 ◽  
Author(s):  
Z Vangelatos ◽  
K Komvopoulos ◽  
CP Grigoropoulos
Keyword(s):  
Strain Energy ◽  
Three Dimensional ◽  
Crystal Lattices ◽  
Mechanical Metamaterials ◽  
Buckling Behavior ◽  
Unit Cells ◽  
Octet Truss ◽  
Topological States ◽  
Energy Dissipated

Mechanical metamaterials are designed to exhibit enhanced properties not found in natural materials or to bolster the properties of existing materials. The theoretical foundations for tuning the mechanical properties have been established, including topological states, controllable buckling behavior, and quasi-two-dimensional mechanical metamaterials with structures containing vacancies. However, the fabrication and experimental procedures to study these structures at the microscale have not been developed yet and the three-dimensional (3D) architectures examined to date are fairly limited. In this study, 3D mechanical metamaterial structures with select unit cells designed to have vacancies were fabricated by multi-photon lithography, having as the principal objective to control (localize) failure and increase the strain energy capacity of the structure. The metamaterial structure from which all the current designs originate is the octet-truss structure, one of the most widely studied 3D metamaterials. The design of the structures was inspired by the role of vacancies in crystal lattices. Vacancies were introduced in the metamaterial structures to allow localized buckling of lattice members to occur in specific unit cells. The significant increase of the strain energy dissipated in these metamaterials is demonstrated by nanoindentation experiments and finite element results. Vacancy effects on the dynamic response of metamaterial structures are also examined in the light of modal analysis simulations. The findings of this study illustrate the importance of strategically placing vacancies in the microlattices of metamaterial structures to control the overall mechanical behavior and greatly increase strain energy dissipation.

scholarly journals Current trends in orthognathic surgery

2021 ◽  
Vol 22 (6) ◽  
pp. 287-295
Author(s):  
Hyung Joon Seo ◽  
Youn-Kyung Choi
Keyword(s):  
Orthognathic Surgery ◽  
Three Dimensional ◽  
Entire Process ◽  
Current Trends ◽  
Obstructive Sleep ◽  
Recent Developments ◽  
Scope Of Application ◽  
Cosmetic Outcomes ◽  
Set Up

Orthognathic surgery has steadily evolved, gradually expanding its scope of application beyond its original purpose of simply correcting malocclusion and the facial profile. For instance, it is now used to treat obstructive sleep apnea and to achieve purely cosmetic outcomes. Recent developments in three-dimensional digital technology are being utilized throughout the entire process of orthognathic surgery, from establishing a surgical plan to printing the surgical splint. These processes have made it possible to perform more sophisticated surgery. The goal of this review article is to introduce current trends in the field of orthognathic surgery and controversies that are under active discussion. The role of a plastic surgeon is not limited to performing orthognathic surgery itself, but also encompasses deep involvement throughout the entire process, including the set-up of surgical occlusion and overall surgical planning. The authors summarize various aspects in the field of orthognathic surgery with the hope of providing helpful information both for plastic surgeons and orthodontists who are interested in orthognathic surgery.

Imaging of platinum-shadowed macromolecular complexes in dark field

1984 ◽  
Vol 42 ◽  
pp. 146-147
Author(s):  
D.W. Andrews ◽  
F.P. Ottensmeyer
Keyword(s):  
Thin Film ◽  
Three Dimensional ◽  
Average Diameter ◽  
Dark Field ◽  
Bright Field ◽  
Field Mode ◽  
Macromolecular Complexes ◽  
Average Mass ◽  
Topological Features ◽  
Projection Images

Shadowing with heavy metals has been used for many years to enhance the topological features of biological macromolecular complexes. The three dimensional features present in directionaly shadowed specimens often simplifies interpretation of projection images provided by other techniques. One difficulty with the method is the relatively large amount of metal used to achieve sufficient contrast in bright field images. Thick shadow films are undesirable because they decrease resolution due to an increased tendency for microcrystalline aggregates to form, because decoration artefacts become more severe and increased cap thickness makes estimation of dimensions more uncertain.The large increase in contrast provided by the dark field mode of imaging allows the use of shadow replicas with a much lower average mass thickness. To form the images in Fig. 1, latex spheres of 0.087 μ average diameter were unidirectionally shadowed with platinum carbon (Pt-C) and a thin film of carbon was indirectly evaporated on the specimen as a support.

How do histone modifications contribute to transgenerational epigenetic inheritance in C. elegans?

2020 ◽  
Vol 48 (3) ◽  
pp. 1019-1034 ◽  
Author(s):  
Rachel M. Woodhouse ◽  
Alyson Ashe
Keyword(s):  
Histone Modifications ◽  
Molecular Mechanisms ◽  
Epigenetic Inheritance ◽  
Nematode Caenorhabditis Elegans ◽  
Histone Methyltransferases ◽  
Transgenerational Epigenetic Inheritance ◽  
C Elegans ◽  
Recent Developments ◽  
Gene Regulatory

Gene regulatory information can be inherited between generations in a phenomenon termed transgenerational epigenetic inheritance (TEI). While examples of TEI in many animals accumulate, the nematode Caenorhabditis elegans has proven particularly useful in investigating the underlying molecular mechanisms of this phenomenon. In C. elegans and other animals, the modification of histone proteins has emerged as a potential carrier and effector of transgenerational epigenetic information. In this review, we explore the contribution of histone modifications to TEI in C. elegans. We describe the role of repressive histone marks, histone methyltransferases, and associated chromatin factors in heritable gene silencing, and discuss recent developments and unanswered questions in how these factors integrate with other known TEI mechanisms. We also review the transgenerational effects of the manipulation of histone modifications on germline health and longevity.

The Role of Three-Dimensional Imaging in Evaluation of the Sinonasal Mass

1996 ◽  
Vol 34 (1) ◽  
pp. 27
Author(s):  
Sue Yon Shim ◽  
Ki Joon Sung ◽  
Young Ju Kim ◽  
In Soo Hong ◽  
Myung Soon Kim ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Three Dimensional Imaging ◽  
Sinonasal Mass

Homogenization and Mass Identity vs. Individual Identity. An Analysis in the Light of the Theory of “The Three Dimensional Spiral of Sense

2016 ◽  
Vol 2 (2) ◽  
pp. 40
Author(s):  
Miriam Aparicio
Keyword(s):  
Three Dimensional ◽  
Individual Identity ◽  
Cognitive Effects ◽  
The Media

This study tests some hypotheses included in the psycho-social-communicational paradigm, which emphasizes the cognitive effects of the media and the role of the psychosocial subject as the recipient

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