这项工作是由维克森林化学系和维克森林中心能源，环境和可持续发展（CEES）的支持。我们感谢查尔斯·穆尼和北卡罗莱纳州立大学与SEM拍摄辅助的分析仪器设备。

1.准备干凝胶颗粒<ol><li>凝胶合成<ol><li>添加25毫米磁力搅拌棒和113毫升去离子水至500mL烧杯中。磁搅拌在不形成旋涡率最高的去离子水。 </li><li>慢慢无水氯化锆13.05克（0.056摩尔）以小的增量添加到去离子水中。所有的无水氯化锆溶解后，添加葡萄糖的53.29克（0.296摩尔）至溶液中。 </li><li>在所有葡萄糖的已溶解在该溶液中，添加硝酸钇六水合物3.73克（0.01摩尔）至溶液中。增加磁力搅拌的至〜700转的速率和等待所有的硝酸钇六水合物的溶液中溶解。 </li><li>添加42毫升的环氧丙烷到该溶液中。继续在700〜转速下搅拌该环氧丙烷与水溶液混合。一旦环氧丙烷与水溶液（〜10秒）混合，降低磁性搅拌吨O〜150转。 </li><li>继续搅拌，直到磁性搅拌棒停止移动由于形成凝胶的。该凝胶通常形成在3分钟内。 注意:添加无水氯化锆到去离子水中是高度放热的反应，并且如果它被添加太快无水氯化锆将羽。 在第1.1节中提供的制剂中。对应于葡萄糖，以总金属（锆+钇）的4.5摩尔比1。代表结果部分包括用于血糖为0总金属摩尔比数据:1，2.25:1和4.5:1。葡萄糖在制剂中的量仅由葡萄糖溶液中的溶解度的限制。作为参考，在葡萄糖的水在20℃下的最大溶解度是47.8重量％。 15 </li></ol></li><li>老龄化和洗涤凝胶<ol><li>紧密覆盖包含用Parafilm凝胶中的烧杯中，并让它年龄24个小时通过使该被覆盖的烧杯中于室温下。 </li><li>从烧杯中取出盖，倒出在凝胶顶部的液体。 </li><li>添加300毫升的无水乙醇中，以含有凝胶的烧杯中，盖紧用Parafilm烧杯中，并留下在室温下将烧杯覆盖24小时。 </li><li>重复步骤1.2.3总共三个乙醇洗涤过的72小时的总时间两次。 </li></ol></li><li>将凝胶干燥成干凝胶<ol><li>从烧杯中取出凝胶，并使用实验室刮刀将其放置在2L瓷蒸发皿（顶部外径24厘米）。 </li><li>破凝胶成约1cm×1cm的片用抹刀和摊开片蒸发皿的表面上。 </li><li>让在环境条件下的凝胶块干燥一周或直至凝胶干燥。该凝胶被认为是干的时候才可以被研磨成细粉。 </li><li>研磨所有的干凝胶与一个研钵细粉。 注意:一旦凝胶是干的，它是认为是一种干凝胶，因为它在环境条件下干燥。 </li></ol></li><li>按干凝胶制成颗粒<ol><li>放置1克干凝胶粉末的成直径为13mm的圆筒状压丸机模头。 </li><li>使用液压机，应用22千牛力为90秒至干凝胶凝胶压成丸粒。 </li><li>慢慢松开新闻界施加的力。慢慢地退出了颗粒沉淀模具，然后小心地取出小球。 </li></ol></li></ol> 2.烧结干凝胶颗粒在惰性气氛中<ol><li>放置干凝胶沉淀在氧化铝或氧化钇稳定的氧化锆板和板装入管式炉的中心。 </li><li>在三分之一每分钟工作管的容积的速率流动的氩气。这对应于750毫升的氩气流量·分钟-1在这项工作中使用的工作管。放空气体出口到通风橱。 </li><li>流动氩气的至少15分钟bEFORE开始以加热管式炉中。 </li><li>同时以恒定速率，程序管式炉的温度控制器，以下列加热程序连续流动的氩气: <ol><li>保持在室温下15分钟。 </li><li>热至850℃以5℃的升温速率·分钟-1。 </li><li>热到所需的烧结温度在2℃·分钟-1的升温速率。 </li><li>保持在所期望的烧结温度下2小时。 </li><li>冷却至850℃，以2℃的升温速率·分钟-1。 </li><li>冷却至室温，在5℃分钟-1的升温速率。 </li></ol></li><li>启动该程序并仔细检查的是，管式炉被加热以下在2.3节中所提供的时间表。 </li><li>从管式炉中除去颗粒中的加热程序完成后。 </li></ol> 3.确定碳模板浓度<ol><li>切〜50毫克片出来的烧结干凝胶粒料使用工具刀和研磨成用玛瑙研钵和研杵细粉。 </li><li>地方〜50毫克细粉末放进氧化铝样品杯为热重量分析。 </li><li>使用热重分析仪（TGA），加热样品以10℃的速率·分钟-1从环境温度到1200℃，同时在100毫升的速率流过样品空气·分钟-1。 </li><li>计算在重量发生之间〜350℃和〜700℃的变化百分比。此重量百分比对应于样品中的总碳含量。 注:如果在350℃〜700℃范围内发生的重量增加，碳化物相已形成和碳含量的计算比较复杂。对于这种情况，请参考文献中描述的计算。 14个碳元素分析已被用来确认碳含量可以从TGA测量来计算。 </li></ol> 4.准备高比表面积YSZ脚手架由碳去除模板<ol><li>放置烧结干凝胶沉淀在氧化铝坩埚。 </li><li>放置在坩埚到箱式炉中在700℃下2小时。 </li><li>小心地从箱式炉用不锈钢坩埚钳的热坩埚，并允许它除去多孔，白色YSZ支架之前冷却至室温一小时。 </li></ol>

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我们什么都没有透露。

与此原位碳模板化方法，可以创建并在传统的陶瓷支架的烧结温度保持在混合金属氧化物nanomorphology。所得到的表面区域比传统烧结支架更高高达80倍且至多比复合物沉积技术制造的支架高4倍。 14氧化丙烯葡萄糖凝胶系统是用于调谐碳模板的浓度，允许一个系统地控制10体积％的碳和几乎100体积％之间的碳碳模板浓度非常灵活。 还有的程序三个关键步?...

的固体氧化物燃料电池（SOFC）很有希望作为一种替代能源转换技术为高效地生成清洁的电能。 1取得了重大进展在研究这项技术的发展作出的;然而，在电极性能的改进仍然需要实现可靠的商业化。电极通常包括与装饰支架表面上的电催化颗粒的多孔陶瓷支架。甲大量的研究集中在提高电催化颗粒的表面积以提高性能，2，3，4，5，6，7，8，但有上增加支架的表面积非常小的研究。增加支架表面因为它们在高温下烧结，1100℃至1500℃区域是具有挑战性的。 通过传统的烧结处理的支架通常具有0.1-1米2·克-1的比表面积。 8，9，10，11上有增加支架表面积的报道很少。在一种情况下，传统上烧结支架的表面积通过溶解和支架表面的沉淀用氢氟酸增强，实现了2米2·克-1的比表面积。 12在另一个，通过使用脉冲激光沉积完全避免高温，实现为20m 2·克-1的比表面积。 13我们的技术的发展背后的原理是建立一个低成本的制造的过程，提供了前所未有的支架表面区域，并使用传统的烧结温度，使得该方法可以很容易地通过。与技术报告这里，支架的表面积高达80米2·克-1已被证实，而在传统的烧结温度下被处理。 14 我们的研究主要是由SOFC电极工程的动机，但技术更广泛地应用于其他领域和应用。一般来说， 原位碳模板的方法是，可以产生纳米结构的，高表面积的混合金属陶瓷材料粉末或多孔支架形式的灵活的方法。正是在这种混合金属陶瓷组合物，表面积，孔隙度和孔径大小都可以被系统地调谐灵活。高的温度通常需要以形成混合金属陶瓷所希望的相，并且该方法保留陶瓷nanomorphology瓦特往往微不足道，允许一个基本上选择任意的加工温度。 该方法涉及一个杂化无机 - 有机 - 丙烯基氧化物凝胶的合成，与金属离子的阱限定化学计量和无机的比率有机物含量。将凝胶在环境条件下干燥，以形成干凝胶。干凝胶在氩气氛中，在所期望的温度下烧结。在加热时，有机成分分解留下原位碳模板，这仍然是用于烧结的持续时间。碳模板随后通过低温氧化除去在空气中，导致纳米结构化，高表面积陶瓷。

<table><tbody><tr><td>Zirconium(IV) chloride, 99.5+%</td><td>Alfa Aesar</td><td>12104</td><td>Air sensitive</td></tr><tr><td>Yttium(III) nitrate hexadydrate, 99.9%</td><td>Alfa Aesar</td><td>12898</td><td>Oxidizer</td></tr><tr><td>D+ Glucose Anhydrous, &amp;ge;99.5%</td><td>US Biological Life Sciences</td><td>G3050</td><td></td></tr><tr><td>(&amp;plusmn;)-Propylene Oxide, &amp;ge;99%</td><td>Sigma Aldrich</td><td>110205</td><td>Extremely flammable</td></tr><tr><td>Ethanol 200 Proof</td><td>Decon Laboratories, Inc.</td><td>2716GEA</td><td></td></tr><tr><td>Argon, 99.997%</td><td>Airgas</td><td>AR 300</td><td>Industrial grade</td></tr></tbody></table>

high temperature fabrication of nanostructured yttria-stabilized-zirconia (ysz) scaffolds by in situ carbon templating xerogels

我们证明为多孔的，纳米结构的氧化钇稳定的氧化锆的高温制造（YSZ，8摩尔％的氧化钇- 92摩尔％的氧化锆）的方法，具有可调谐的比表面积的支架高达80米2·克-1。锆盐，钇盐和葡萄糖的水溶液是与环氧丙烷（PO）混合以形成凝胶。将凝胶在环境条件下干燥，以形成干凝胶。干凝胶压成丸粒，然后在氩气气氛中烧结。在烧结过程中，一个YSZ陶瓷相形式和有机成分分解，留下无定形碳。 原位形成碳用作硬模板，在烧结温度下保持高的表面积YSZ nanomorphology。碳随后通过氧化除去在空气中在低温下，从而产生多孔的，纳米结构的YSZ的支架。碳模板和最终支架表面积的浓度可以是系统性通过在凝胶合成改变葡萄糖浓度LY调谐。使用中，表面积和孔径分布是由物理吸附测量来确定热重量分析（TGA）中的碳模板浓度进行定量，并使用扫描电子显微镜（SEM）的形貌进行了表征。相纯度和微晶尺寸使用X射线衍射（XRD）测定。这种制造方法提供了一种新颖的，用于实现前所未有的支架表面积和nanomorphologies用于基于陶瓷的电化学能量转换应用灵活的平台， 例如固体氧化物燃料电池（SOFC）的电极。

相纯度通过如先前通过科塔姆等报道的X射线衍射（XRD）确认。作为碳模板浓度的函数14 YSZ支架比表面积示于图1。浓度被示出为在烧结干凝胶粒料总固体的体积百分数。碳模板浓度有系统地与凝胶制剂增加的葡萄糖浓度增加而增加。金属的摩尔比从0:1至4.5: 如图1所示，比表面积系统通过增加葡萄糖为10米2·克...

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High Temperature Fabrication of Nanostructured Yttria-Stabilized-Zirconia YSZ Scaffolds by In Situ Carbon Templating Xerogels

一种用于在1000℃和1400℃之间的温度的制造多孔纳米结构的氧化钇稳定的氧化锆（YSZ）的支架协议被呈现。

通过纳米氧化钇稳定的二氧化锆（YSZ）的支架的高温加工<em&gt;原位</em&gt;碳模板干凝胶

We demonstrate a method for the high temperature fabrication of porous, nanostructured yttria-stabilized-zirconia (YSZ, 8 mol% yttria - 92 mol% zirconia) ...

high-temperature-fabrication-nanostructured-yttria-stabilized

Research

JoVE Journal

Engineering

High Temperature Fabrication of Nanostructured Yttria-Stabilized-Zirconia (YSZ) Scaffolds by In Situ Carbon Templating Xerogels

10.5K 次观看.  Wake Forest University. 一种用于在1000℃和1400℃之间的温度的制造多孔纳米结构的氧化钇稳定的氧化锆（YSZ）的支架协议被呈现。 

视频: High Temperature Fabrication of Nanostructured Yttria-Stabilized-Zirconia YSZ Scaffolds by In Situ Carbon Templating Xerogels

Fabrication, Densification, and Replica Molding of 3D Carbon Nanotube Microstructures

The introduction of new materials and processes to microfabrication has, in large part, enabled many important advances in microsystems, lab-on-a-chip devices, and their applications. In particular, capabilities for cost-effective fabrication of polymer microstructures were transformed by the advent of soft lithography and other micromolding techniques 1, 2, and this led a revolution in applications of microfabrication to biomedical engineering and biology. Nevertheless, it remains challenging to fabricate microstructures with well-defined nanoscale surface textures, and to fabricate arbitrary 3D shapes at the micro-scale. Robustness of master molds and maintenance of shape integrity is especially important to achieve high fidelity replication of complex structures and preserving their nanoscale surface texture. The combination of hierarchical textures, and heterogeneous shapes, is a profound challenge to existing microfabrication methods that largely rely upon top-down etching using fixed mask templates. On the other hand, the bottom-up synthesis of nanostructures such as nanotubes and nanowires can offer new capabilities to microfabrication, in particular by taking advantage of the collective self-organization of nanostructures, and local control of their growth behavior with respect to microfabricated patterns. 
Our goal is to introduce vertically aligned carbon nanotubes (CNTs), which we refer to as CNT "forests", as a new microfabrication material. We present details of a suite of related methods recently developed by our group: fabrication of CNT forest microstructures by thermal CVD from lithographically patterned catalyst thin films; self-directed elastocapillary densification of CNT microstructures; and replica molding of polymer microstructures using CNT composite master molds. In particular, our work shows that self-directed capillary densification ("capillary forming"), which is performed by condensation of a solvent onto the substrate with CNT microstructures, significantly increases the packing density of CNTs. This process enables directed transformation of vertical CNT microstructures into straight, inclined, and twisted shapes, which have robust mechanical properties exceeding those of typical microfabrication polymers. This in turn enables formation of nanocomposite CNT master molds by capillary-driven infiltration of polymers. The replica structures exhibit the anisotropic nanoscale texture of the aligned CNTs, and can have walls with sub-micron thickness and aspect ratios exceeding 50:1. Integration of CNT microstructures in fabrication offers further opportunity to exploit the electrical and thermal properties of CNTs, and diverse capabilities for chemical and biochemical functionalization 3.

We present methods for fabrication of patterned microstructures of vertically aligned carbon nanotubes (CNTs), and their use as master molds for production of polymer microstructures with organized nanoscale surface texture. The CNT forests are densified by condensation of solvent onto the substrate, which significantly increases their packing density and enables self-directed formation of 3D shapes.

制备，致密，副本三维碳纳米管微结构成型

The introduction of new materials and processes to microfabrication has, in large part, enabled many important advances in microsystems, lab-on-a-chip ...

科研

工程学

Preparation and Reactivity of Gasless Nanostructured Energetic Materials

High-Energy Ball Milling (HEBM) is a ball milling process where a powder mixture placed in the ball mill is subjected to high-energy collisions from the balls. Among other applications, it is a versatile technique that allows for effective preparation of gasless reactive nanostructured materials with high energy density per volume (Ni+Al, Ta+C, Ti+C). The structural transformations of reactive media, which take place during HEBM, define the reaction mechanism in the produced energetic&#160;composites. Varying the processing conditions permits fine tuning of the milling-induced microstructures of the fabricated composite particles. In turn, the reactivity, i.e., self-ignition temperature, ignition delay time, as well as reaction kinetics, of high energy density materials depends on its microstructure. Analysis of the milling-induced microstructures suggests that the formation of fresh oxygen-free intimate high surface area contacts between the reagents is responsible for the enhancement of their reactivity. This manifests itself in a reduction of ignition temperature and delay time, an increased rate of chemical reaction, and an overall decrease of the effective activation energy of the reaction. The protocol provides a detailed description for the preparation of reactive nanocomposites with tailored microstructure using short-term HEBM method. It also describes a high-speed thermal imaging technique to determine the ignition/combustion characteristics of the energetic materials. The protocol can be adapted to preparation and characterization of a variety of nanostructured energetic composites.

This protocol describes the preparation of gasless nanostructured energetic materials (Ni+Al, Ta+C, Ti+C) using the short-term high-energy ball milling (HEBM) technique. It also describes a high-speed thermal imaging method to study the reactivity of mechanically fabricated nanocomposites. These protocols can be extended to other reactive nanostructured energetic materials.

准备和无气腹纳米结构的反应含能材料

High-Energy Ball Milling (HEBM) is a ball milling process where a powder mixture placed in the ball mill is subjected to high-energy collisions from the ...

Formation of Thick Dense Yttrium Iron Garnet Films Using Aerosol Deposition

Aerosol deposition (AD) is a thick-film deposition process that can produce layers up to several hundred micrometers thick with densities greater than 95% of the bulk. The primary advantage of AD is that the deposition takes place entirely at ambient temperature; thereby enabling film growth in material systems with disparate melting temperatures. This report describes in detail the processing steps for preparing the powder and for performing AD using the custom-built system. Representative characterization results are presented from scanning electron microscopy, profilometry, and ferromagnetic resonance for films grown in this system. As a representative overview of the capabilities of the system, focus is given to a sample produced following the described protocol and system setup. Results indicate that this system can successfully deposit 11 &#181;m thick yttrium iron garnet films that are &#160;&#62; 90% of the bulk density during a single 5 min deposition run. A discussion of methods to afford better control of the aerosol and particle selection for improved thickness and roughness variations in the film is provided.

This report describes the use of a custom-built system to perform aerosol deposition of thick films of yttrium iron garnet onto sapphire substrates at RT. The deposited films are characterized using scanning electron microscopy, profilometry, and ferromagnetic resonance to give a representative overview of the capabilities of the technique.

浓稠钇铁石榴石薄膜的形成使用气溶胶沉积

Aerosol deposition (AD) is a thick-film deposition process that can produce layers up to several hundred micrometers thick with densities greater than 95% ...

Aerosol-assisted Chemical Vapor Deposition of Metal Oxide Structures: Zinc Oxide Rods

Whilst columnar zinc oxide (ZnO) structures in the form of rods or wires have been synthesized previously by different liquid- or vapor-phase routes, their high cost production and/or incompatibility with microfabrication technologies, due to the use of pre-deposited catalyst-seeds and/or high processing temperatures exceeding 900 &#176;C, represent a drawback for a widespread use of these methods. Here, however, we report the synthesis of ZnO rods via a non-catalyzed vapor-solid mechanism enabled by using an aerosol-assisted chemical vapor deposition (CVD) method at 400 &#176;C with zinc chloride (ZnCl2) as the precursor and ethanol as the carrier solvent. This method provides both single-step formation of ZnO rods and the possibility of their direct integration with various substrate types, including silicon, silicon-based micromachined platforms, quartz, or high heat resistant polymers. This potentially facilitates the use of this method at a large-scale, due to its compatibility with state-of-the-art microfabrication processes for device manufacture. This report also describes the properties of these structures (e.g., morphology, crystalline phase, optical band gap, chemical composition, electrical resistance) and validates its gas sensing functionality towards carbon monoxide.

Columnar zinc oxide structures in the form of rods are synthesized via aerosol-assisted chemical vapor deposition without the use of pre-deposited catalyst-seed particles. This method is scalable and compatible with various substrates based on either silicon, quartz or polymers.

金属氧化物结构的气溶胶辅助化学气相沉积: 氧化锌棒

Whilst columnar zinc oxide (ZnO) structures in the form of rods or wires have been synthesized previously by different liquid- or vapor-phase routes, ...

化学

Chemical Synthesis of Porous Barium Titanate Thin Film and Thermal Stabilization of Ferroelectric Phase by Porosity-Induced Strain

Barium titanate (BaTiO3, hereafter BT) is an established ferroelectric material first discovered in the 1940s and still widely used because of its well-balanced ferroelectricity, piezoelectricity, and dielectric constant. In addition, BT does not contain any toxic elements. Therefore, it is considered to be an eco-friendly material, which has attracted considerable interest as a replacement for lead zirconate titanate (PZT). However, bulk BT loses its ferroelectricity at approximately 130 &#176;C, thus, it cannot be used at high temperatures. Because of the growing demand for high-temperature ferroelectric materials, it is important to enhance the thermal stability of ferroelectricity in BT. In previous studies, strain originating from the lattice mismatch at hetero-interfaces has been used. However, the sample preparation in this approach requires complicated and expensive physical processes, which are undesirable for practical applications.
In this study, we propose a chemical synthesis of a porous material as an alternative means of introducing strain. We synthesized a porous BT thin film using a surfactant-assisted sol-gel method, in which self-assembled amphipathic surfactant micelles were used as an organic template. Through a series of studies, we clarified that the introduction of pores had a similar effect on distorting the BT crystal lattice, to that of a hetero-interface, leading to the enhancement and stabilization of ferroelectricity. Owing to its simplicity and cost effectiveness, this fabrication process has considerable advantages over conventional methods.

Here, we present a protocol for the synthesis of porous barium titanate (BaTiO3) thin film by a surfactant-assisted sol-gel method, in which self-assembled amphipathic surfactant micelles are used as an organic template.

孔隙诱导应变法合成多孔钛酸钡薄膜及铁电相热稳定性

Barium titanate (BaTiO3, hereafter BT) is an established ferroelectric material first discovered in the 1940s and still widely used because of its ...

Multi-material Ceramic-Based Components &#8211; Additive Manufacturing of Black-and-white Zirconia Components by Thermoplastic 3D-Printing (CerAM - T3DP)

To combine the benefits of Additive Manufacturing (AM) with the benefits of Functionally Graded Materials (FGM) to ceramic-based 4D components (three dimensions for the geometry and one degree of freedom concerning the material properties at each position) the Thermoplastic 3D-Printing (CerAM -&#160;T3DP) was developed. It is a direct AM technology which allows the AM of multi-material components. To demonstrate the advantages of this technology black-and-white zirconia components were additively manufactured and co-sintered defect-free.
Two different pairs of black and white zirconia powders were used to prepare different thermoplastic suspensions. Appropriate dispensing parameters were investigated to manufacture single-material test components and adjusted for the additive manufacturing of multi-color zirconia components.

Here we describe a protocol for additively manufacturing black-and-white zirconia components by Thermoplastic 3D-Printing (CerAM -&#160;T3DP) and co-sintering defect-free.

多材料陶瓷基元器件--用热塑性3d 印刷 (ceram-t3dp) 制备黑白氧化锆部件的添加剂

To combine the benefits of Additive Manufacturing (AM) with the benefits of Functionally Graded Materials (FGM) to ceramic-based 4D components (three ...

Fused Filament Fabrication (FFF) of Metal-Ceramic Components

Technical ceramics are widely used for industrial and research applications, as well as for consumer goods. Today, the demand for complex geometries with diverse customization options and favorable production methods is increasing continuously. With fused filament fabrication (FFF), it is possible to produce large and complex components quickly with high material efficiency. In FFF, a continuous thermoplastic filament is melted in a heated nozzle and deposited below. The computer-controlled print head is moved in order to build up the desired shape layer by layer. Investigations regarding printing of metals or ceramics are increasing more and more in research and industry. This study focuses on additive manufacturing (AM) with a multi-material approach to combine a metal (stainless steel) with a technical ceramic (zirconia: ZrO2). Combining these materials offers a broad variety of applications due to their different electrical and mechanical properties. The paper shows the main issues in preparation of the material and feedstock, device development, and printing of these composites.

Fused Filament Fabrication FFF of Metal-Ceramic Components

This study shows multi-material additive manufacturing (AM) using fused filament fabrication (FFF) of stainless steel and zirconia.

金属陶瓷元件的熔融长丝制造 (fff)

Technical ceramics are widely used for industrial and research applications, as well as for consumer goods. Today, the demand for complex geometries with ...

Additive Manufacturing of Functionally Graded Ceramic Materials by Stereolithography

An additive manufacturing technology is applied to obtain functionally graded ceramic parts. This technology, based on digital light processing/stereolithography, is developed within the scope of the CerAMfacturing European research project. A three-dimensional (3-D) hemi-maxillary bone-like structure is 3-D printed using custom aluminum oxide polymeric mixtures. The powders and mixtures are fully analyzed in terms of rheological behavior in order to ensure proper material handling during the printing process. The possibility to print functionally graded materials using the Admaflex technology is explained in this document. Field-emission scanning electron microscopy (FESEM) show that the sintered aluminum oxide ceramic part has a porosity lower than 1% and no remainder of the original layered structure is found after analysis.

This manuscript describes the processing of single multifunctional ceramic components (e.g., combinations of dense-porous structures) additively manufactured by stereolithography.

立体平版印刷法对功能分级陶瓷材料的添加剂制造

An additive manufacturing technology is applied to obtain functionally graded ceramic parts. This technology, based on digital light ...

Fabrication of Mechanically Tunable and Bioactive Metal Scaffolds for Biomedical Applications

Biometal systems have been widely used for biomedical applications, in particular, as load-bearing materials. However, major challenges are high stiffness and low bioactivity of metals. In this study, we have developed a new method towards fabricating a new type of bioactive and mechanically reliable porous metal scaffolds-densified porous Ti scaffolds. The method consists of two fabrication processes, 1) the fabrication of porous Ti scaffolds by dynamic freeze casting, and 2) coating and densification of the porous scaffolds. The dynamic freeze casting method to fabricate porous Ti scaffolds allowed the densification of porous scaffolds by minimizing the chemical contamination and structural defects. The densification process is distinctive for three reasons. First, the densification process is simple, because it requires a control of only one parameter (degree of densification). Second, it is effective, as it achieves mechanical enhancement and sustainable release of biomolecules from porous scaffolds. Third, it has broad applications, as it is also applicable to the fabrication of functionally graded porous scaffolds by spatially varied strain during densification.

Bioactive and mechanically reliable metal scaffolds have been fabricated through a method which consists of two processes, dynamic freeze casting for the fabrication of porous Ti, and coating and densification of the Ti scaffolds. The densification process is simple, effective and applicable to the fabrication of functionally graded scaffolds.

加工机械可调和生物活性金属支架的生物医学应用

Biometal systems have been widely used for biomedical applications, in particular, as load-bearing materials. However, major challenges are high stiffness ...

生物工程

Epitaxial Nanostructured &alpha;-Quartz Films on Silicon: From the Material to New Devices

In this work, we show a detailed engineering route of the first piezoelectric nanostructured epitaxial quartz-based microcantilever. We will explain all the steps in the process starting from the material to the device fabrication. The epitaxial growth of &#945;-quartz film on SOI (100) substrate starts with the preparation of a strontium doped silica sol-gel and continues with the deposition of this gel into the SOI substrate in a thin film form using the dip-coating technique under atmospheric conditions at room temperature. Before crystallization of the gel film, nanostructuration is performed onto the film surface by nanoimprint lithography (NIL). Epitaxial film growth is reached at 1000 &#176;C, inducing a perfect crystallization of the patterned gel film. Fabrication of quartz crystal cantilever devices is a four-step process based on microfabrication techniques. The process starts with shaping the quartz surface, and then metal deposition for electrodes follows it. After removing the silicone, the cantilever is released from SOI substrate eliminating SiO2 between silicon and quartz. The device performance is analyzed by non-contact laser vibrometer (LDV) and atomic force microscopy (AFM). Among the different cantilever&#8217;s dimensions included in the fabricated chip, the nanostructured cantilever analyzed in this work exhibited a dimension of 40 &#181;m large and 100 &#181;m long and was fabricated with a 600 nm thick patterned quartz layer (nanopillar diameter and separation distance of 400 nm and 1 &#181;m, respectively) epitaxially grown on a 2 &#181;m thick Si device layer. The&#160;measured&#160;resonance frequency was&#160;267 kHz and the estimated quality factor, Q, of the whole mechanical structure was Q ~ 398 under low vacuum conditions. We observed the voltage-dependent linear displacement of cantilever with both techniques (i.e., AFM contact measurement and LDV). Therefore, proving that these devices can be activated through the indirect piezoelectric effect.

Epitaxial Nanostructured &#945;-Quartz Films on Silicon: From the Material to New Devices

This work presents a detailed protocol for the microfabrication of nanostructured &#945;-quartz cantilever on a Silicon-On-Insulator(SOI) technology substrate starting from the epitaxial growth of quartz film with the dip coating method and then nanostructuration of the thin film via nanoimprint lithography.

硅上显性纳米结构α石英薄膜:从材料到新设备

In this work, we show a detailed engineering route of the first piezoelectric nanostructured epitaxial quartz-based microcantilever. We will explain all ...

通过纳米氧化钇稳定的二氧化锆（YSZ）的支架的高温加工

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