A New 4 × 4 Rectangular Waveguide Short-Slot Coupler in 3D Printed Technology at Ku-Band

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.

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Conductive Polymer Composites Based Flexible Strain Sensors by 3D Printing: A Mini-Review

Frontiers in Materials ◽

10.3389/fmats.2021.725420 ◽

2021 ◽

Vol 8 ◽

Author(s):

Libing Liu ◽

Dong Xiang ◽

Yuanpeng Wu ◽

Zuoxin Zhou ◽

Hui Li ◽

...

Keyword(s):

3D Printing ◽

Polymer Composites ◽

High Performance ◽

Low Cost ◽

Wearable Sensors ◽

Conductive Polymer ◽

Strain Sensors ◽

Layer By Layer ◽

Conductive Polymer Composites ◽

3D Printed

With the development of wearable electronic devices, conductive polymer composites (CPCs) based flexible strain sensors are gaining tremendous popularity. In recent years, the applications of additive manufacturing (AM) technology (also known as 3D printing) in fabricating CPCs based flexible strain sensors have attracted the attention of researchers due to their advantages of mold-free structure, low cost, short time, and high accuracy. AM technology, based on material extrusion, photocuring, and laser sintering, produces complex and high-precision CPCs based wearable sensors through layer-by-layer stacking of printing material. Some high-performance CPCs based strain sensors are developed by employing different 3D printing technologies and printing materials. In this mini-review, we summarize and discuss the performance and applications of 3D printed CPCs based strain sensors in recent years. Finally, the current challenges and prospects of 3D printed strain sensors are also discussed to provide an insight into the future of strain sensors using 3D printing technology.

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A millifluidic chip for cultivation of fish embryos and toxicity testing fabricated by 3D printing technology

RSC Advances ◽

10.1039/d1ra00846c ◽

2021 ◽

Vol 11 (33) ◽

pp. 20507-20518

Author(s):

Petr Panuška ◽

Zuzana Nejedlá ◽

Jiří Smejkal ◽

Petr Aubrecht ◽

Michaela Liegertová ◽

...

Keyword(s):

3D Printing ◽

Toxicity Testing ◽

Toxicity Screening ◽

Printing Technology ◽

3D Printing Technology ◽

Fish Embryos ◽

3D Printed ◽

Novel Design

A novel design of 3D printed zebrafish millifluidic system for embryonic long-term cultivation and toxicity screening has been developed. The chip unit provides 24 cultivation chambers and a selective individual embryo removal functionality.

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Microstructured Surface Plasmon Resonance Sensor Based on Inkjet 3D Printing Using Photocurable Resins with Tailored Refractive Index

Polymers ◽

10.3390/polym13152518 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2518

Author(s):

Nunzio Cennamo ◽

Lorena Saitta ◽

Claudio Tosto ◽

Francesco Arcadio ◽

Luigi Zeni ◽

...

Keyword(s):

Surface Plasmon Resonance ◽

3D Printing ◽

Surface Plasmon ◽

Plasmon Resonance ◽

Optical Sensor ◽

Low Cost ◽

3D Print ◽

Spr Sensor ◽

Resonance Sensor ◽

3D Printed

In this work, a novel approach to realize a plasmonic sensor is presented. The proposed optical sensor device is designed, manufactured, and experimentally tested. Two photo-curable resins are used to 3D print a surface plasmon resonance (SPR) sensor. Both numerical and experimental analyses are presented in the paper. The numerical and experimental results confirm that the 3D printed SPR sensor presents performances, in term of figure of merit (FOM), very similar to other SPR sensors made using plastic optical fibers (POFs). For the 3D printed sensor, the measured FOM is 13.6 versus 13.4 for the SPR-POF configuration. The cost analysis shows that the 3D printed SPR sensor can be manufactured at low cost (∼15 €) that is competitive with traditional sensors. The approach presented here allows to realize an innovative SPR sensor showing low-cost, 3D-printing manufacturing free design and the feasibility to be integrated with other optical devices on the same plastic planar support, thus opening undisclosed future for the optical sensor systems.

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Additive technology applied to the realization of K-band microwave terminations: reproducibility improvement

International Journal of Microwave and Wireless Technologies ◽

10.1017/s1759078717001404 ◽

2018 ◽

Vol 10 (1) ◽

pp. 3-8

Author(s):

Azar Maalouf ◽

Ronan Gingat ◽

Vincent Laur

Keyword(s):

3D Printing ◽

Frequency Band ◽

Rectangular Waveguide ◽

Three Dimensional ◽

Low Density ◽

Support Material ◽

Additive Technology ◽

3D Printed ◽

K Band

This study examines K-band rectangular waveguide terminations with three-dimensional (3D)-printed loads, and proposes an Asymmetrical Tapered Wedge topology. This geometry shows a good tradeoff between microwave performance and 3D-printing issues (printing directions and support material requirements), thus improving noticeably the reproducibility of the devices. The effect of the density of the 3D-printed load on the reflection parameter of the termination was investigated. Even for a low density, reflection level remained below −27.5 dB between 18 and 26.5 GHz. Reproducibility was demonstrated by the characterization of six loads that were 3D printed under the same conditions. Measurements demonstrate that a maximum reflection parameter level of −33.5 dB can be ensured over the whole frequency band without any post-machining of the 3D-printed devices.

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Accessing 3D Printed Vascular Phantoms for Procedural Simulation

Frontiers in Surgery ◽

10.3389/fsurg.2020.626212 ◽

2021 ◽

Vol 7 ◽

Author(s):

Jasamine Coles-Black ◽

Damien Bolton ◽

Jason Chuen

Keyword(s):

3D Printing ◽

Endovascular Procedures ◽

Low Cost ◽

3D Models ◽

Routine Care ◽

Aortic Aneurysms ◽

Patient Specific ◽

Ct Angiogram ◽

Abdominal Aortic ◽

3D Printed

Introduction: 3D printed patient-specific vascular phantoms provide superior anatomical insights for simulating complex endovascular procedures. Currently, lack of exposure to the technology poses a barrier for adoption. We offer an accessible, low-cost guide to producing vascular anatomical models using routine CT angiography, open source software packages and a variety of 3D printing technologies.Methods: Although applicable to all vascular territories, we illustrate our methodology using Abdominal Aortic Aneurysms (AAAs) due to the strong interest in this area. CT aortograms acquired as part of routine care were converted to representative patient-specific 3D models, and then printed using a variety of 3D printing technologies to assess their material suitability as aortic phantoms. Depending on the technology, phantoms cost $20–$1,000 and were produced in 12–48 h. This technique was used to generate hollow 3D printed thoracoabdominal aortas visible under fluoroscopy.Results: 3D printed AAA phantoms were a valuable addition to standard CT angiogram reconstructions in the simulation of complex cases, such as short or very angulated necks, or for positioning fenestrations in juxtarenal aneurysms. Hollow flexible models were particularly useful for device selection and in planning of fenestrated EVAR. In addition, these models have demonstrated utility other settings, such as patient education and engagement, and trainee and anatomical education. Further study is required to establish a material with optimal cost, haptic and fluoroscopic fidelity.Conclusion: We share our experiences and methodology for developing inexpensive 3D printed vascular phantoms which despite material limitations, successfully mimic the procedural challenges encountered during live endovascular surgery. As the technology continues to improve, 3D printed vascular phantoms have the potential to disrupt how endovascular procedures are planned and taught.

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Novel 3D-Printed MEMS Magnetometer with Optical Detection

Proceedings ◽

10.3390/proceedings2130783 ◽

2018 ◽

Vol 2 (13) ◽

pp. 783 ◽

Cited By ~ 1

Author(s):

Matthias Kahr ◽

Wilfried Hortschitz ◽

Harald Steiner ◽

Michael Stifter ◽

Andreas Kainz ◽

...

Keyword(s):

3D Printing ◽

Product Development ◽

Rapid Prototyping ◽

Low Cost ◽

High Accuracy ◽

Structural Performance ◽

Sensitivity Measurement ◽

Optical Readout ◽

3D Printed ◽

Working Principle

This paper reports a novel 3D printed MEMS magnetometer with optical readout, which demonstrates the advantages of 3D printing technology in terms of rapid prototyping. Low-cost and fast product development cycles favour 3D printing as an effective tool. Sensitivity measurement with such devices indicate high accuracy and good structural performance, considering material and technological uncertainties. This paper is focusing on the novelty of the rapid, 3D-printing prototyping approach and verification of the working principle for printed MEMS magnetometers.

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

Journal of Materials Chemistry C ◽

10.1039/d0tc02660c ◽

2020 ◽

Vol 8 (28) ◽

pp. 9495-9501 ◽

Cited By ~ 1

Author(s):

Sayli Jambhulkar ◽

Weiheng Xu ◽

Rahul Franklin ◽

Dharneedar Ravichandran ◽

Yuxiang Zhu ◽

...

Keyword(s):

3D Printing ◽

Self Assembly ◽

High Performance ◽

Chemical Sensor ◽

Carbon Nanofiber ◽

Polymer Nanoparticle ◽

3D Printed

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

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An Initial Effort to Create a Superficial Femoral Artery Ultrasound Phantom Using 3-Dimensional Printing

Journal for Vascular Ultrasound ◽

10.1177/1544316720911490 ◽

2020 ◽

Vol 44 (2) ◽

pp. 69-73

Author(s):

Paul D. Bishop ◽

Thomas Fultz ◽

Lisa Smith ◽

Ryan S. Klatte ◽

Francis Loth ◽

...

Keyword(s):

3D Printing ◽

Femoral Artery ◽

Superficial Femoral Artery ◽

Low Cost ◽

Duplex Ultrasound ◽

3D Print ◽

Stl File ◽

Calcified Plaque ◽

3D Printed ◽

Artery Geometry

Three-dimensional (3D) printing of anatomical structures has yielded valuable models for simulation, education, and surgical planning applications. Applications for 3D printing have continued to expand to include some ultrasound applications. The goal of this effort was to evaluate if a 3D printed model of a superficial femoral artery (SFA) would have realistic ultrasound characteristics. A computed tomography scan was 3D reconstructed and segmented using TeraRecon Aquarius Intuition software (TeraRecon, Foster City, California) to obtain an atherosclerotic SFA geometry. Both the lumen geometry and calcified plaque geometry of the SFA were exported as a stereolithographic (STL) file. The STL file was printed with An Object350 Connex 3D System using 2 different materials selected based on published elastic modulus data. VeroWhite was selected for the calcified plaque and TangoPlus Clear was selected for the artery wall. After printing, the SFA model was imaged in a water bath with a Phillips IU22 duplex ultrasound console and L12-9 ultrasound probe. Ultrasound imaging of the SFA model yielded grayscale views of artery geometry. Lumen geometry of the SFA model was similar to the actual artery geometry. Ultrasound was able to discern between the 3D print materials and visualize regions with stenosis. Suboptimal ultrasound parameters of echogenicity and wave velocity noted to differ from biological tissue. Total 3D print material cost was estimated at below $20. Although the 3D printed model did not have fully accurate ultrasound characteristics, it still provided realistic imaging. With further research, 3D printed models may offer a low-cost alternative for ultrasound phantoms.

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Development of Soft sEMG Sensing Structures Using 3D-Printing Technologies

Sensors ◽

10.3390/s20154292 ◽

2020 ◽

Vol 20 (15) ◽

pp. 4292

Author(s):

Gerjan Wolterink ◽

Pedro Dias ◽

Remco G. P. Sanders ◽

Frodo Muijzer ◽

Bert-Jan van Beijnum ◽

...

Keyword(s):

3D Printing ◽

Biceps Brachii ◽

Low Cost ◽

Recognition Algorithm ◽

Practical Applications ◽

Variable Level ◽

Processing Step ◽

Significant Difference ◽

3D Printed ◽

Emg Electrodes

3D printing of soft EMG sensing structures enables the creation of personalized sensing structures that can be potentially integrated in prosthetic, assistive and other devices. We developed and characterized flexible carbon-black doped TPU-based sEMG sensing structures. The structures are directly 3D-printed without the need for an additional post-processing step using a low-cost, consumer grade multi-material FDM printer. A comparison between the gold standard Ag/AgCl gel electrodes and the 3D-printed EMG electrodes with a comparable contact area shows that there is no significant difference in the EMG signals’ amplitude. The sensors are capable of distinguishing a variable level of muscle activity of the biceps brachii. Furthermore, as a proof of principle, sEMG data of a 3D-printed 8-electrode band are analyzed using a patten recognition algorithm to recognize hand gestures. This work shows that 3D-printed sEMG electrodes have great potential in practical applications.

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Evaluation of a Desktop 3D Printed Rigid Refractive-Indexed-Matched Flow Phantom for PIV Measurements on Cerebral Aneurysms

Cardiovascular Engineering and Technology ◽

10.1007/s13239-019-00444-z ◽

2019 ◽

Vol 11 (1) ◽

pp. 14-23 ◽

Cited By ~ 1

Author(s):

W. H. Ho ◽

I. J. Tshimanga ◽

M. N. Ngoepe ◽

M. C. Jermy ◽

P. H. Geoghegan

Keyword(s):

3D Printing ◽

Flow Visualization ◽

Investment Casting ◽

Flow Model ◽

Low Cost ◽

Ammonium Thiocyanate ◽

Cerebral Aneurysms ◽

Model Material ◽

Flow Phantom ◽

3D Printed

Abstract Purpose Fabrication of a suitable flow model or phantom is critical to the study of biomedical fluid dynamics using optical flow visualization and measurement methods. The main difficulties arise from the optical properties of the model material, accuracy of the geometry and ease of fabrication. Methods Conventionally an investment casting method has been used, but recently advancements in additive manufacturing techniques such as 3D printing have allowed the flow model to be printed directly with minimal post-processing steps. This study presents results of an investigation into the feasibility of fabrication of such models suitable for particle image velocimetry (PIV) using a common 3D printing Stereolithography process and photopolymer resin. Results An idealised geometry of a cerebral aneurysm was printed to demonstrate its applicability for PIV experimentation. The material was shown to have a refractive index of 1.51, which can be refractive matched with a mixture of de-ionised water with ammonium thiocyanate (NH4SCN). The images were of a quality that after applying common PIV pre-processing techniques and a PIV cross-correlation algorithm, the results produced were consistent within the aneurysm when compared to previous studies. Conclusions This study presents an alternative low-cost option for 3D printing of a flow phantom suitable for flow visualization simulations. The use of 3D printed flow phantoms reduces the complexity, time and effort required compared to conventional investment casting methods by removing the necessity of a multi-part process required with investment casting techniques.

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