Research

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14 pages, 4576 KiB

Open AccessArticle

Nanoimprint Mold Consisting of an Adhesive Lap Joint between a Nanopatterned Metal Sleeve and a Carbon Composite Roll

by Amin Khaliq, Muhammad Ahmad Kamran and Myung Yung Jeong

Nanomaterials 2023, 13(10), 1685; https://0-doi-org.brum.beds.ac.uk/10.3390/nano13101685 - 20 May 2023

Viewed by 1428

Roll-to-roll nanoimprinting is an emerging technology that has revolutionized the sectors of flexible electronics, thin films, and solar cells with its high throughput. However, there is still room for improvement. In this study, a FEM analysis (in ANSYS) was carried out on a [...] Read more.

Roll-to-roll nanoimprinting is an emerging technology that has revolutionized the sectors of flexible electronics, thin films, and solar cells with its high throughput. However, there is still room for improvement. In this study, a FEM analysis (in ANSYS) was carried out on a large-area roll-to-roll nanoimprint system in which the master roller consists of a large nanopatterned nickel mold joined to a carbon fiber reinforced polymer (CFRP) base roller using epoxy adhesive. Deflections and pressure uniformity of the nano-mold assembly were analyzed under loadings of different magnitudes in a roll-to-roll nanoimprinting setup. Optimization of deflections was performed with applied loadings, and the lowest deflection value was 97.69 nm. The adhesive bond viability was assessed under a range of applied forces. Finally, potential strategies to reduce deflections were also discussed, which can be helpful in increasing pressure uniformity. Full article

(This article belongs to the Special Issue Scalable Fabrication of Nanostructured Materials and Devices)

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8 pages, 1591 KiB

Open AccessArticle

Freestanding Metal Nanomembranes and Nanowires by Template Transfer with a Soluble Adhesive

by Peipei Jia, Xinzhong Wang, Xiaobing Cai, Qiuquan Guo, Dongxing Zhang, Yong Sun and Jun Yang

Nanomaterials 2022, 12(22), 3988; https://0-doi-org.brum.beds.ac.uk/10.3390/nano12223988 - 12 Nov 2022

Viewed by 1292

Abstract

The fabrication of nanostructures usually involves chemical processes that have in certain steps. Especially, it is necessary to use the chemical etching method to release the as-patterned structures from the substrate in most of the transfer techniques. Here, a novel scheme of template [...] Read more.

The fabrication of nanostructures usually involves chemical processes that have in certain steps. Especially, it is necessary to use the chemical etching method to release the as-patterned structures from the substrate in most of the transfer techniques. Here, a novel scheme of template transfer as developed for the fabrication of freestanding Au nanomembranes and nanowires by using a soluble PVP adhesive. The nanomembranes feature the periodic nanohole arrays with high uniformity. Without the substrates, these plasmonic nanohole arrays show symmetric and antisymmetric resonance modes with bright and dark spectral features, respectively, in transmission. Through the spectral analysis for reflection, we have disclosed that the usual dark mode in transmission is not really dark, but it reveals a distinct feature in reflection. Two coupling modes present distinct spectral features in transmission and reflection due to their different loss channels. To show their versatility, the freestanding nanomembranes were also employed as secondary templates to form Si nanowire arrays by the metal-assisted chemical etching method. Full article

(This article belongs to the Special Issue Scalable Fabrication of Nanostructured Materials and Devices)

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12 pages, 3301 KiB

Open AccessArticle

Nanoimprinted and Anodized Templates for Large-Scale and Low-Cost Nanopatterning

by David Navas, David G. Trabada and Manuel Vázquez

Nanomaterials 2021, 11(12), 3430; https://0-doi-org.brum.beds.ac.uk/10.3390/nano11123430 - 17 Dec 2021

Cited by 2 | Viewed by 2036

Abstract

Nanopatterning to fabricate advanced nanostructured materials is a widely employed technology in a broad spectrum of applications going from spintronics and nanoelectronics to nanophotonics. This work reports on an easy route for nanopatterning making use of ordered porous templates with geometries ranging from [...] Read more.

Nanopatterning to fabricate advanced nanostructured materials is a widely employed technology in a broad spectrum of applications going from spintronics and nanoelectronics to nanophotonics. This work reports on an easy route for nanopatterning making use of ordered porous templates with geometries ranging from straight lines to square, triangular or rhombohedral lattices, to be employed for the designed growth of sputtered materials with engineered properties. The procedure is based on large-scale nanoimprinting using patterned low-cost commercial disks, as 1-D grating stamps, followed by a single electrochemical process that allows one to obtain 1-D ordered porous anodic templates. Multiple imprinting steps at different angles enable more complex 2-D patterned templates. Subsequently, sputtering facilitates the growth of ferromagnetic antidot thin films (e.g., from 20 to 100 nm Co thick layers) with designed symmetries. This technique constitutes a non-expensive method for massive mold production and pattern generation avoiding standard lithographical techniques. In addition, it overcomes current challenges of the two-stage electrochemical porous anodic alumina templates: (i) allowing the patterning of large areas with high ordering and/or complex antidot geometries, and (ii) being less-time consuming. Full article

(This article belongs to the Special Issue Scalable Fabrication of Nanostructured Materials and Devices)

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12 pages, 3432 KiB

Open AccessArticle

Characterization of 3D Printed Yttria-Stabilized Zirconia Parts for Use in Prostheses

by Irene Buj-Corral, Daniel Vidal, Aitor Tejo-Otero, José Antonio Padilla, Elena Xuriguera and Felip Fenollosa-Artés

Nanomaterials 2021, 11(11), 2942; https://0-doi-org.brum.beds.ac.uk/10.3390/nano11112942 - 03 Nov 2021

Cited by 19 | Viewed by 2471

Abstract

The main aim of the present paper is to study and analyze surface roughness, shrinkage, porosity, and mechanical strength of dense yttria-stabilized zirconia (YSZ) samples obtained by means of the extrusion printing technique. In the experiments, both print speed and layer height were [...] Read more.

The main aim of the present paper is to study and analyze surface roughness, shrinkage, porosity, and mechanical strength of dense yttria-stabilized zirconia (YSZ) samples obtained by means of the extrusion printing technique. In the experiments, both print speed and layer height were varied, according to a 2² factorial design. Cuboid samples were defined, and three replicates were obtained for each experiment. After sintering, the shrinkage percentage was calculated in width and in height. Areal surface roughness, S_a, was measured on the lateral walls of the cuboids, and total porosity was determined by means of weight measurement. The compressive strength of the samples was determined. The lowest S_a value of 9.4 μm was obtained with low layer height and high print speed. Shrinkage percentage values ranged between 19% and 28%, and porosity values between 12% and 24%, depending on the printing conditions. Lowest porosity values correspond to low layer height and low print speed. The same conditions allow obtaining the highest average compressive strength value of 176 MPa, although high variability was observed. For this reason, further research will be carried out about mechanical strength of ceramic 3D printed samples. The results of this work will help choose appropriate printing conditions extrusion processes for ceramics. Full article

(This article belongs to the Special Issue Scalable Fabrication of Nanostructured Materials and Devices)

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12 pages, 7403 KiB

Open AccessArticle

A Scalable Solution Route to Porous Networks of Nanostructured Black Tungsten

by V. Vinay K. Doddapaneni, Kijoon Lee, Tyler T. Colbert, Saereh Mirzababaei, Brian K. Paul, Somayeh Pasebani and Chih-Hung Chang

Nanomaterials 2021, 11(9), 2304; https://0-doi-org.brum.beds.ac.uk/10.3390/nano11092304 - 05 Sep 2021

Cited by 1 | Viewed by 2044

Abstract

This paper studied the feasibility of a new solution-processed method to manufacture black tungsten nanostructures by laser conversion of tungsten hexacarbonyl precursor on the Inconel 625 substrate under argon atmosphere at ambient pressure. The results show that sublimation of the precursor can be [...] Read more.

This paper studied the feasibility of a new solution-processed method to manufacture black tungsten nanostructures by laser conversion of tungsten hexacarbonyl precursor on the Inconel 625 substrate under argon atmosphere at ambient pressure. The results show that sublimation of the precursor can be prevented if the decomposition temperature (>170 °C) is achieved using the laser heating method. Three different laser powers from 60–400 W were used to investigate the role of laser parameters on the conversion. It was found that lower laser power of 60 W resulted in a mixture of unconverted precursor and converted tungsten. Higher laser powers >200 W resulted in α-W (BCC) in one step without further heat treatment. Different oxygen concentrations from 0.5 ppm to 21 vol% were used in the laser canister to investigate the effect of oxygen concentration on the conversion. It was found that the hard vacuum (>10⁻⁴ torr) or hydrogen is not necessary to obtain α-W (BCC). The solar absorptance varied from 63–97%, depending on the amount of precursor deposited on the substrate and oxygen content in the laser canister. This solution-based laser conversion of tungsten precursor is a scalable method to manufacture tungsten coatings for high-temperature applications. Full article

(This article belongs to the Special Issue Scalable Fabrication of Nanostructured Materials and Devices)

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9 pages, 3401 KiB

Open AccessArticle

Large-Area Biocompatible Random Laser for Wearable Applications

by Kun Ge, Dan Guo, Xiaojie Ma, Zhiyang Xu, Anwer Hayat, Songtao Li and Tianrui Zhai

Nanomaterials 2021, 11(7), 1809; https://0-doi-org.brum.beds.ac.uk/10.3390/nano11071809 - 12 Jul 2021

Cited by 12 | Viewed by 2242

Abstract

Recently, wearable sensor technology has drawn attention to many health-related appliances due to its varied existing optical, electrical, and mechanical applications. Similarly, we have designed a simple and cheap lift-off fabrication technique for the realization of large-area biocompatible random lasers to customize wearable [...] Read more.

Recently, wearable sensor technology has drawn attention to many health-related appliances due to its varied existing optical, electrical, and mechanical applications. Similarly, we have designed a simple and cheap lift-off fabrication technique for the realization of large-area biocompatible random lasers to customize wearable sensors. A large-area random microcavity comprises a matrix element polymethyl methacrylate (PMMA) in which rhodamine B (RhB, which acts as a gain medium) and gold nanorods (Au NRs, which offer plasmonic feedback) are incorporated via a spin-coating technique. In regards to the respective random lasing device residing on a heterogenous film (area > 100 cm²), upon optical excitation, coherent random lasing with a narrow linewidth (~0.4 nm) at a low threshold (~23 μJ/cm² per pulse) was successfully attained. Here, we maneuvered the mechanical flexibility of the device to modify the spacing between the feedback agents (Au NRs), which tuned the average wavelength from 612.6 to 624 nm under bending while being a recoverable process. Moreover, the flexible film can potentially be used on human skin such as the finger to serve as a motion and relative-humidity sensor. This work demonstrates a designable and simple method to fabricate a large-area biocompatible random laser for wearable sensing. Full article

(This article belongs to the Special Issue Scalable Fabrication of Nanostructured Materials and Devices)

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8 pages, 3336 KiB

Open AccessArticle

Low-Threshold Microlasers Based on Holographic Dual-Gratings

by Tianrui Zhai, Liang Han, Xiaojie Ma and Xiaolei Wang

Nanomaterials 2021, 11(6), 1530; https://0-doi-org.brum.beds.ac.uk/10.3390/nano11061530 - 09 Jun 2021

Cited by 3 | Viewed by 1788

Abstract

Among the efforts to improve the performances of microlasers, optimization of the gain properties and cavity parameters of these lasers has attracted significant attention recently. Distributed feedback lasers, as one of the most promising candidate technologies for electrically pumped microlasers, can be combined [...] Read more.

Among the efforts to improve the performances of microlasers, optimization of the gain properties and cavity parameters of these lasers has attracted significant attention recently. Distributed feedback lasers, as one of the most promising candidate technologies for electrically pumped microlasers, can be combined with dual-gratings. This combination provides additional freedom for the design of the laser cavity. Here, a holographic dual-grating is designed to improve the distributed feedback laser performance. The holographic dual-grating laser consists of a colloidal quantum dot film with two parallel gratings, comprising first-order (210 nm) and second-order (420 nm) gratings that can be fabricated easily using a combination of spin coating and interference lithography. The feedback and the output from the cavity are controlled using the first-order grating and the second-order grating, respectively. Through careful design and analysis of the dual-grating, a balance is achieved between the feedback and the cavity output such that the lasing threshold based on the dual-grating is nearly half the threshold of conventional distributed feedback lasers. Additionally, the holographic dual-grating laser shows a high level of stability because of the high stability of the colloidal quantum dots against photobleaching. Full article

(This article belongs to the Special Issue Scalable Fabrication of Nanostructured Materials and Devices)

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Review

Jump to: Research

34 pages, 8842 KiB

Open AccessReview

A Review on Progress, Challenges, and Prospects of Material Jetting of Copper and Tungsten

by V. Vinay K. Doddapaneni, Kijoon Lee, Havva Eda Aysal, Brian K. Paul, Somayeh Pasebani, Konstantinos A. Sierros, Chinedum E. Okwudire and Chih-hung Chang

Nanomaterials 2023, 13(16), 2303; https://0-doi-org.brum.beds.ac.uk/10.3390/nano13162303 - 10 Aug 2023

Cited by 1 | Viewed by 1776

Abstract

Copper (Cu) and tungsten (W) possess exceptional electrical and thermal conductivity properties, making them suitable candidates for applications such as interconnects and thermal conductivity enhancements. Solution-based additive manufacturing (SBAM) offers unique advantages, including patterning capabilities, cost-effectiveness, and scalability among the various methods for [...] Read more.

Copper (Cu) and tungsten (W) possess exceptional electrical and thermal conductivity properties, making them suitable candidates for applications such as interconnects and thermal conductivity enhancements. Solution-based additive manufacturing (SBAM) offers unique advantages, including patterning capabilities, cost-effectiveness, and scalability among the various methods for manufacturing Cu and W-based films and structures. In particular, SBAM material jetting techniques, such as inkjet printing (IJP), direct ink writing (DIW), and aerosol jet printing (AJP), present a promising approach for design freedom, low material wastes, and versatility as either stand-alone printers or integrated with powder bed-based metal additive manufacturing (MAM). Thus, this review summarizes recent advancements in solution-processed Cu and W, focusing on IJP, DIW, and AJP techniques. The discussion encompasses general aspects, current status, challenges, and recent research highlights. Furthermore, this paper addresses integrating material jetting techniques with powder bed-based MAM to fabricate functional alloys and multi-material structures. Finally, the factors influencing large-scale fabrication and potential prospects in this area are explored. Full article

(This article belongs to the Special Issue Scalable Fabrication of Nanostructured Materials and Devices)

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21 pages, 4242 KiB

Open AccessReview

Ink Formulation and Printing Parameters for Inkjet Printing of Two Dimensional Materials: A Mini Review

by Ho-Young Jun, Se-Jung Kim and Chang-Ho Choi

Nanomaterials 2021, 11(12), 3441; https://0-doi-org.brum.beds.ac.uk/10.3390/nano11123441 - 19 Dec 2021

Cited by 21 | Viewed by 5426

Abstract

Inkjet printing of two-dimensional (2D) material has been a center of interest for wearable electronics and has become a promising platform for next-generation technologies. Despite the enormous progress made in printed 2D materials, there are still challenges in finding the optimal printing conditions [...] Read more.

Inkjet printing of two-dimensional (2D) material has been a center of interest for wearable electronics and has become a promising platform for next-generation technologies. Despite the enormous progress made in printed 2D materials, there are still challenges in finding the optimal printing conditions involving the ink formulation and printing parameters. Adequate ink formulation and printing parameters for target 2D materials rely on empirical studies and repeated trials. Therefore, it is essential to compile promising strategies for ink formulation and printing parameters. In this context, this review discusses the optimal ink formulations to prepare stable ink and steady ink jetting and then explores the critical printing parameters for fabricating printed 2D materials of a high quality. The summary and future prospects for inkjet-printed 2D materials are also addressed. Full article

(This article belongs to the Special Issue Scalable Fabrication of Nanostructured Materials and Devices)

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