scholarly journals Flexible 3D Printed Conductive Metamaterial Units for Electromagnetic Applications in Microwaves

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3879
Author(s):  
Anna C. Tasolamprou ◽  
Despoina Mentzaki ◽  
Zacharias Viskadourakis ◽  
Eleftherios N. Economou ◽  
Maria Kafesaki ◽  
...  

In this work we present a method for fabricating three dimensional, ultralight and flexible millimeter metamaterial units using a commercial household 3D printer. The method is low-cost, fast, eco-friendly and accessible. In particular, we use the Fused Deposition Modeling 3D printing technique and we fabricate flexible conductive Spilt Ring Resonators (SRRs) in a free-standing form. We characterized the samples experimentally through measurements of their spectral transmission, using standard rectangular microwave waveguides. Our findings show that the resonators produce well defined resonant electromagnetic features that depend on the structural details and the infiltrating dielectric materials, indicating that the thin, flexible and light 3D printed structures may be used as electromagnetic microwave components and electromagnetic fabrics for coating a variety of devices and infrastructure units, while adapting to different shapes and sizes.

2021 ◽  
pp. 002199832098856
Author(s):  
Marcela Piassi Bernardo ◽  
Bruna Cristina Rodrigues da Silva ◽  
Luiz Henrique Capparelli Mattoso

Injured bone tissues can be healed with scaffolds, which could be manufactured using the fused deposition modeling (FDM) strategy. Poly(lactic acid) (PLA) is one of the most biocompatible polymers suitable for FDM, while hydroxyapatite (HA) could improve the bioactivity of scaffold due to its chemical composition. Therefore, the combination of PLA/HA can create composite filaments adequate for FDM and with high osteoconductive and osteointegration potentials. In this work, we proposed a different approache to improve the potential bioactivity of 3D printed scaffolds for bone tissue engineering by increasing the HA loading (20-30%) in the PLA composite filaments. Two routes were investigated regarding the use of solvents in the filament production. To assess the suitability of the FDM-3D printing process, and the influence of the HA content on the polymer matrix, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were performed. The HA phase content of the composite filaments agreed with the initial composite proportions. The wettability of the 3D printed scaffolds was also increased. It was shown a greener route for obtaining composite filaments that generate scaffolds with properties similar to those obtained by the solvent casting, with high HA content and great potential to be used as a bone graft.


Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 655 ◽  
Author(s):  
Seong-Woo Hong ◽  
Ji-Young Yoon ◽  
Seong-Hwan Kim ◽  
Sun-Kon Lee ◽  
Yong-Rae Kim ◽  
...  

In this study, a soft structure with its stiffness tunable by an external field is proposed. The proposed soft beam structure consists of a skin structure with channels filled with a magnetorheological fluid (MRF). Two specimens of the soft structure are fabricated by three-dimensional printing and fused deposition modeling. In the fabrication, a nozzle is used to obtain channels in the skin of the thermoplastic polyurethane, while another nozzle is used to fill MRF in the channels. The specimens are tested by using a universal tensile machine to evaluate the relationships between the load and deflection under two different conditions, without and with permanent magnets. It is empirically shown that the stiffness of the proposed soft structure can be altered by activating the magnetic field.


ACS Omega ◽  
2020 ◽  
Vol 5 (19) ◽  
pp. 11147-11150 ◽  
Author(s):  
Dirk Volker Woortman ◽  
Martina Haack ◽  
Norbert Mehlmer ◽  
Thomas B. Brück

2019 ◽  
Vol 25 (1) ◽  
pp. 82-87
Author(s):  
Wenqiong Su ◽  
Yulong Li ◽  
Lulu Zhang ◽  
Jiahui Sun ◽  
Shuopeng Liu ◽  
...  

Typography-like templates for polydimethylsiloxane (PDMS) microfluidic chips using a fused deposition modeling (FDM) three-dimensional (3D) printer are presented. This rapid and fast proposed scheme did not require complicated photolithographic fabrication facilities and could deliver resolutions of ~100 μm. Polylactic acid (PLA) was adopted as the material to generate the 3D-printed units, which were then carefully assembled on a glass substrate using a heat-melt-curd strategy. This craft of bonding offers a cost-effective way to design and modify the templates of microfluidic channels, thus reducing the processing time of microfluidic chips. Finally, a flexible microfluidic chip to be employed for cell-based drug screening was developed based on the modularized 3D-printed templates. The lithography-free, typography-like, 3D-printed templates create a modularized fabrication process and promote the prevalence of integrated microfluidic systems with minimal requirements and improved efficiency.


2021 ◽  
Vol 18 (1) ◽  
pp. 07-13
Author(s):  
Neha Thakur ◽  
Hari Murthy

Three-dimensional printing (3DP) is a digitally-controlled additive manufacturing technique used for fast prototyping. This paper reviews various 3D printing techniques like Selective Laser Sintering (SLS), Fused Deposition Modeling, (FDM), Semi-solid extrusion (SSE), Stereolithography (SLA), Thermal Inkjet (TIJ) Printing, and Binder jetting 3D Printing along with their application in the field of medicine. Normal medicines are based on the principle of “one-size-fits-all”. This is not true always, it is possible medicine used for curing one patient is giving some side effects to another. To overcome this drawback “3D Printed medicines” are developed. In this paper, 3D printed medicines forming different Active Pharmaceutical Ingredients (API) are reviewed. Printed medicines are capable of only curing the diseases, not for the diagnosis. Nanomedicines have “theranostic” ability which combines therapeutic and diagnostic. Nanoparticles are used as the drug delivery system (DDS) to damaged cells’ specific locations. By the use of nanomedicine, the fast recovery of the disease is possible. The plant-based nanoparticles are used with herbal medicines which give low-cost and less toxic medication called nanobiomedicine. 4D and 5D printing technology for the medical field are also enlightened in this paper.


Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2144
Author(s):  
Maria Sevastaki ◽  
Mirela Petruta Suchea ◽  
George Kenanakis

In the present work, the use of nanocomposite polymeric filaments based on 100% recycled solid polystyrene everyday products, enriched with TiO2 nanoparticles with mass concentrations up to 40% w/w, and the production of 3D photocatalytic structures using a typical fused deposition modeling (FDM)-type 3D printer are reported. We provide evidence that the fabricated 3D structures offer promising photocatalytic properties, indicating that the proposed technique is indeed a novel low-cost alternative route for fabricating large-scale photocatalysts, suitable for practical real-life applications.


2014 ◽  
Vol 657 ◽  
pp. 795-799 ◽  
Author(s):  
Anastasios Chatzikonstantinou ◽  
Dimitrios Tzetzis ◽  
Panagiotis Kyratsis ◽  
Nikolaos Bilalis

The current work demonstrates a feasibility study on the generation of a copy, having a highly complex geometry, of a Greek paleontological find utilising reverse engineering and low-cost rapid prototyping techniques. A part of the jaw bone of a cave bear (Ursus spelaeus) that lived during the Pleistocene and became extinct about 10,000 years ago was digitized using a three-dimensional laser scanner. The resulting point-cloud of the scans was treated with a series of advanced software for the creation of surfaces and ultimately for a digital model. The generated model was three-dimensionally built by the aid of a Fused Deposition Modeling (FDM) apparatus. An analytical methodology is presented revealing the step by step approach from the scanning to the prototyping. It is believed that a variety of interested parties could benefit from such an analytical approach, including, production engineers, three-dimensional CAD users and designers, paleontologists and museum curators.


2022 ◽  
Vol 8 ◽  
Author(s):  
Charbel Tawk ◽  
Rahim Mutlu ◽  
Gursel Alici

A single universal robotic gripper with the capacity to fulfill a wide variety of gripping and grasping tasks has always been desirable. A three-dimensional (3D) printed modular soft gripper with highly conformal soft fingers that are composed of positive pressure soft pneumatic actuators along with a mechanical metamaterial was developed. The fingers of the soft gripper along with the mechanical metamaterial, which integrates a soft auxetic structure and compliant ribs, was 3D printed in a single step, without requiring support material and postprocessing, using a low-cost and open-source fused deposition modeling (FDM) 3D printer that employs a commercially available thermoplastic poly (urethane) (TPU). The soft fingers of the gripper were optimized using finite element modeling (FEM). The FE simulations accurately predicted the behavior and performance of the fingers in terms of deformation and tip force. Also, FEM was used to predict the contact behavior of the mechanical metamaterial to prove that it highly decreases the contact pressure by increasing the contact area between the soft fingers and the grasped objects and thus proving its effectiveness in enhancing the grasping performance of the gripper. The contact pressure can be decreased by up to 8.5 times with the implementation of the mechanical metamaterial. The configuration of the highly conformal gripper can be easily modulated by changing the number of fingers attached to its base to tailor it for specific manipulation tasks. Two-dimensional (2D) and 3D grasping experiments were conducted to assess the grasping performance of the soft modular gripper and to prove that the inclusion of the metamaterial increases its conformability and reduces the out-of-plane deformations of the soft monolithic fingers upon grasping different objects and consequently, resulting in the gripper in three different configurations including two, three and four-finger configurations successfully grasping a wide variety of objects.


Author(s):  
Aya Abdalla ◽  
Bhavik Anil Patel

Three-dimensional (3D) printing has recently emerged as a novel approach in the development of electrochemical sensors. This approach to fabrication has provided a tremendous opportunity to make complex geometries of electrodes at high precision. The most widely used approach for fabrication is fused deposition modeling; however, other approaches facilitate making smaller geometries or expanding the range of materials that can be printed. The generation of complete analytical devices, such as electrochemical flow cells, provides an example of the array of analytical tools that can be developed. This review highlights the fabrication, design, preparation, and applications of 3D printed electrochemical sensors. Such developments have begun to highlight the vast potential that 3D printed electrochemical sensors can have compared to other strategies in sensor development. Expected final online publication date for the Annual Review of Analytical Chemistry, Volume 14 is August 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 318 ◽  
Author(s):  
Pang-Yun Chou ◽  
Ying-Chao Chou ◽  
Yu-Hsuan Lai ◽  
Yu-Ting Lin ◽  
Chia-Jung Lu ◽  
...  

Polycaprolactone/nano-hydroxylapatite (PCL/nHA) nanocomposites have found use in tissue engineering and drug delivery owing to their good biocompatibility with these types of applications in addition to their mechanical characteristics. Three-dimensional (3D) printing of PCL/nHA nanocomposites persists as a defiance mostly because of the lack of commercial filaments for the conventional fused deposition modeling (FDM) method. In addition, as the composites are prepared using FDM for the purpose of delivering pharmaceuticals, thermal energy can destroy the embedded drugs and biomolecules. In this report, we investigated 3D printing of PCL/nHA using a lab-developed solution-extrusion printer, which consists of an extrusion feeder, a syringe with a dispensing nozzle, a collection table, and a command port. The effects of distinct printing variables on the mechanical properties of nanocomposites were investigated. Drug-eluting nanocomposite screws were also prepared using solution-extrusion 3D printing. The empirical outcomes suggest that the tensile properties of the 3D-printed PCL/nHA nanocomposites increased with the PCL/nHA-to-dichloromethane (DCM) ratio, fill density, and print orientation but decreased with an increase in the moving speed of the dispensing tip. Furthermore, printed drug-eluting PCL/nHA screws eluted high levels of antimicrobial vancomycin and ceftazidime over a 14-day period. Solution-extrusion 3D printing demonstrated excellent capabilities for fabricating drug-loaded implants for various medical applications.


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