Integrating 3D printing and self-assembly for layered polymer/nanoparticle microstructures as high-performance sensors

2020 ◽  
Vol 8 (28) ◽  
pp. 9495-9501 ◽  
Author(s):  
Sayli Jambhulkar ◽  
Weiheng Xu ◽  
Rahul Franklin ◽  
Dharneedar Ravichandran ◽  
Yuxiang Zhu ◽  
...  

A 3D printed, preferentially aligned, and alternate-layered polymer–carbon nanofiber microstructure for a high-performance chemical sensor has been fabricated.

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3117
Author(s):  
Krzysztof Rodzeń ◽  
Mary Josephine McIvor ◽  
Preetam K. Sharma ◽  
Jonathan G. Acheson ◽  
Alistair McIlhagger ◽  
...  

Polyetheretherketone (PEEK) is a high-performance thermoplastic polymer which has found increasing application in orthopaedics and has shown a lot of promise for ‘made-to-measure’ implants via additive manufacturing approaches. However, PEEK is bioinert and needs to undergo surface modification to make it at least osteoconductive to ensure a more rapid, improved, and stable fixation that will last longer in vivo. One approach to solving this issue is to modify PEEK with bioactive agents such as hydroxyapatite (HA). The work reported in this study demonstrates the direct 3D printing of PEEK/HA composites of up to 30 weight percent (wt%) HA using a Fused Filament Fabrication (FFF) approach. The surface characteristics and in vitro properties of the composite materials were investigated. X-ray diffraction revealed the samples to be semi-crystalline in nature, with X-ray Photoelectron Spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry revealing HA materials were available in the uppermost surface of all the 3D printed samples. In vitro testing of the samples at 7 days demonstrated that the PEEK/HA composite surfaces supported the adherence and growth of viable U-2 OS osteoblast like cells. These results demonstrate that FFF can deliver bioactive HA on the surface of PEEK bio-composites in a one-step 3D printing process.


Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1369 ◽  
Author(s):  
Yueke Ming ◽  
Yugang Duan ◽  
Ben Wang ◽  
Hong Xiao ◽  
Xiaohui Zhang

Recently, 3D printing of fiber-reinforced composites has gained significant research attention. However, commercial utilization is limited by the low fiber content and poor fiber–resin interface. Herein, a novel 3D printing process to fabricate continuous fiber-reinforced thermosetting polymer composites (CFRTPCs) is proposed. In brief, the proposed process is based on the viscosity–temperature characteristics of the thermosetting epoxy resin (E-20). First, the desired 3D printing filament was prepared by impregnating a 3K carbon fiber with a thermosetting matrix at 130 °C. The adhesion and support required during printing were then provided by melting the resin into a viscous state in the heating head and rapidly cooling after pulling out from the printing nozzle. Finally, a powder compression post-curing method was used to accomplish the cross-linking reaction and shape preservation. Furthermore, the 3D-printed CFRTPCs exhibited a tensile strength and tensile modulus of 1476.11 MPa and 100.28 GPa, respectively, a flexural strength and flexural modulus of 858.05 MPa and 71.95 GPa, respectively, and an interlaminar shear strength of 48.75 MPa. Owing to its high performance and low concentration of defects, the proposed printing technique shows promise in further utilization and industrialization of 3D printing for different applications.


Author(s):  
M. Kosson ◽  
L. Brown ◽  
F. Sanchez

3D printed cement composites with and without carbon nanofiber (CNF) and microfiber (CF) reinforcement within the cement ink were evaluated at seven days and compared with their traditionally cast counterparts. A liquid lubrication layer at the extrusion nozzle was noted. The reinforcement type influenced the formation of the extruded filament, with underextrusion seen during 3D printing with the CNF cement ink while sudden discontinuation of extrusion was experienced during 3D printing with the CF cement ink. No noticeable interfacial region between printed filaments was observed in the 3D printed cement composites, with the exception of air cavities between printed filaments of the composite fabricated with the CNF cement ink. Lower compressive strengths were seen in the direction orthogonal to the print path for the 3D printed composites compared with the cast composites. The addition of CFs within the cement ink reduced this strength difference and led to strain softening in the post peak behavior.


Soft Matter ◽  
2021 ◽  
Author(s):  
Chya-Yan Liaw ◽  
John W Tolbert ◽  
Lesley W Chow ◽  
Murat Guvendiren

Recent advances in extrusion-based filament 3D printing technology enable the processability of high-performance polymers. Poly(ether ether ketone) (PEEK) is an important group of high-performance polymer that has been widely used...


2020 ◽  
Vol 92 (8) ◽  
pp. 1341-1355 ◽  
Author(s):  
Pavel N. Nesterenko

AbstractThe rapid development of additive technologies in recent years is accompanied by their intensive introduction into various fields of science and related technologies, including analytical chemistry. The use of 3D printing in analytical instrumentation, in particular, for making prototypes of new equipment and manufacturing parts having complex internal spatial configuration, has been proved as exceptionally effective. Additional opportunities for the widespread introduction of 3D printing technologies are associated with the development of new optically transparent, current- and thermo-conductive materials, various composite materials with desired properties, as well as possibilities for printing with the simultaneous combination of several materials in one product. This review will focus on the application of 3D printing for production of new advanced analytical devices, such as compact chromatographic columns for high performance liquid chromatography, flow reactors and flow cells for detectors, devices for passive concentration of toxic compounds and various integrated devices that allow significant improvements in chemical analysis. A special attention is paid to the complexity and functionality of 3D-printed devices.


Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 610
Author(s):  
Raúl V. Haro-Baez ◽  
Jorge A. Ruiz-Cruz ◽  
Juan Córcoles ◽  
José R. Montejo-Garai ◽  
Jesús M. Rebollar

This paper presents a novel design of an eight-port directional coupler with a very compact structure and simple manufacturing, working in the Ku frequency band. One of the main goals of the design was to ease the manufacturing with a simple structure: the coupler consisted of four rectangular waveguide input ports, four rectangular waveguide output ports, and a central coupling region with only H-plane variation. A prototype was fabricated using additive manufacturing, with a combination of 3D printing and silver coating metallization. The obtained performance showed a theoretical bandwidth of 6.6% with 20 dB return loss for the input/output ports. Good agreement between simulations and measurements was obtained, validating the proposed coupler as a good trade-off for low cost 3D printing, compactness, and high performance for systems requiring a high number of ports as in phase arrays or Butler matrices.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hongqiu Wei ◽  
Ming Lei ◽  
Ping Zhang ◽  
Jinsong Leng ◽  
Zijian Zheng ◽  
...  

Abstract3D-printing tough conductive hydrogels (TCHs) with complex structures is still a challenging task in related fields due to their inherent contrasting multinetworks, uncontrollable and slow polymerization of conductive components. Here we report an orthogonal photochemistry-assisted printing (OPAP) strategy to make 3D TCHs in one-pot via the combination of rational visible-light-chemistry design and reliable extrusion printing technique. This orthogonal chemistry is rapid, controllable, and simultaneously achieve the photopolymerization of EDOT and phenol-coupling reaction, leading to the construction of tough hydrogels in a short time (tgel ~30 s). As-prepared TCHs are tough, conductive, stretchable, and anti-freezing. This template-free 3D printing can process TCHs to arbitrary structures during the fabrication process. To further demonstrate the merits of this simple OPAP strategy and TCHs, 3D-printed TCHs hydrogel arrays and helical lines, as proofs-of-concept, are made to assemble high-performance pressure sensors and a temperature-responsive actuator. It is anticipated that this one-pot rapid, controllable OPAP strategy opens new horizons to tough hydrogels.


2020 ◽  
Vol 22 (4) ◽  
pp. 2157-2163 ◽  
Author(s):  
Huilan Li ◽  
Xiaofei Wang ◽  
Chu Qi ◽  
Chengcheng Zhao ◽  
Cuimei Fu ◽  
...  

A self-assembled MoO3-decorated carbon nanofiber interlayer is effectively integrated into the Li–S battery with high performance.


2018 ◽  
Vol 6 (3) ◽  
pp. 853-858 ◽  
Author(s):  
Swetha Chandrasekaran ◽  
Eric B. Duoss ◽  
Marcus A. Worsley ◽  
James P. Lewicki

We report 3D printing of a ‘pure’ thermal cure cyanate ester for the fabrication of robust 3D printed structures through the formulation, tailoring and post processing of a custom ‘ink’ for Direct Ink Writing.


2021 ◽  
Author(s):  
Zhiwen Yan ◽  
Yun Qian ◽  
Cunyi Fan

Nerve guide conduits (NGCs) connect dissected nerve stumps and effectively repair short-range peripheral nerve defects. However, for long-range defects, autografts show better therapeutic effects, despite intrinsic limitations. Recent evidence shows that biomimetic design is essential for high-performance NGCs, and 3D printing is a promising fabricating technique. The current work includes a brief review of the challenges for peripheral nerve regeneration. The authors propose a potential solution using biomimetic 3D-printed NGCs as alternative therapies. The assessment of biomimetic designs includes microarchitecture, mechanical property, electrical conductivity and biologics inclusion. The applications of 3D printing in preparing NGCs and present strategies to improve therapeutic effects are also discussed.


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