scholarly journals Intelligent Hydrogel Actuators With Controllable Deformations and Movements

2021 ◽  
Vol 8 ◽  
Author(s):  
Qian Zhao ◽  
Zhenglei Yu ◽  
Yunhong Liang ◽  
Lei Ren ◽  
Luquan Ren
Keyword(s):  
3D Printing ◽  
Near Infrared ◽  
Response Rate ◽  
Three Dimensional ◽  
High Response Rate ◽  
Structure Design ◽  
Forward Movement ◽  
Practical Applications ◽  
3D Printed ◽  
Intelligent Hydrogel

Near infrared laser- (NIR-) driven intelligent hydrogel actuator systems including printable N-isopropylacrylamide- (NIPAm-) nanosized synthetic hectorite clay-nanofibrillated cellulose (NFC) hydrogels and NIPAm-4-hydroxybutyl acrylate- (4HBA-) NFC hydrogels with a high response rate were prepared via three-dimensional (3D) printing and hydrothermal synthesis, respectively. The addition of NFC was beneficial to the improvement in rheology. The 3D printed intelligent hydrogel actuators with a structure pattern of Model I and Model II exhibited the saddle and inverted saddle deformations, respectively, to prove the validity of 3D printing. In order to improve the response rate and enrich movement patterns, the hydrothermal synthesized intelligent hydrogel actuators were prepared on the base of the 3D printed intelligent hydrogel compositions. The addition of NFC maintained the controllable NIR response. Based on a wedge-shaped design, the hydrothermal synthesized intelligent hydrogel pushed the resin ball with weight of 130 mg forward 8 mm in 39 s. By changing the torque values of a hydrogel in a different direction, the actuator realized controllable continuous rollover movement. Attributed to the longilineal shape, the intelligent hydrogel actuator reached an effective displacement of 20 mm in 10 s via a forward movement. The characteristics and structure design of a hydrogel material significantly realized multiple controllable functional four-dimensional (4D) printed deformations and movements. The combination of advantages of the 3D printed and hydrothermal synthesized intelligent hydrogels provided a new direction of development and abundant material candidates for the practical applications of 4D printing in soft robot, information sensing, and health engineering.

scholarly journals Dense ceramics with complex shape fabricated by 3D printing: A review

2021 ◽  
Author(s):  
Zhe Chen ◽  
Xiaohong Sun ◽  
Yunpeng Shang ◽  
Kunzhou Xiong ◽  
Zhongkai Xu ◽  
...  
Keyword(s):  
3D Printing ◽  
Complex Shape ◽  
Raw Materials ◽  
Three Dimensional ◽  
Critical Parameters ◽  
Printing Process ◽  
Practical Applications ◽  
3D Printing Technology ◽  
3D Printed ◽  
Ceramic Density

AbstractThree-dimensional (3D) printing technology is becoming a promising method for fabricating highly complex ceramics owing to the arbitrary design and the infinite combination of materials. Insufficient density is one of the main problems with 3D printed ceramics, but concentrated descriptions of making dense ceramics are scarce. This review specifically introduces the principles of the four 3D printing technologies and focuses on the parameters of each technology that affect the densification of 3D printed ceramics, such as the performance of raw materials and the interaction between energy and materials. The technical challenges and suggestions about how to achieve higher ceramic density are presented subsequently. The goal of the presented work is to comprehend the roles of critical parameters in the subsequent 3D printing process to prepare dense ceramics that can meet the practical applications.

scholarly journals Three-dimensional printing for heart diseases: clinical application review

2021 ◽  
Author(s):  
Yanyan Ma ◽  
Peng Ding ◽  
Lanlan Li ◽  
Yang Liu ◽  
Ping Jin ◽  
...  
Keyword(s):  
3D Printing ◽  
Clinical Application ◽  
Heart Diseases ◽  
Three Dimensional ◽  
Convincing Evidence ◽  
Surgical Interventions ◽  
Three Dimensional Printing ◽  
Complex Anatomy ◽  
Precise Understanding ◽  
3D Printed

AbstractHeart diseases remain the top threat to human health, and the treatment of heart diseases changes with each passing day. Convincing evidence shows that three-dimensional (3D) printing allows for a more precise understanding of the complex anatomy associated with various heart diseases. In addition, 3D-printed models of cardiac diseases may serve as effective educational tools and for hands-on simulation of surgical interventions. We introduce examples of the clinical applications of different types of 3D printing based on specific cases and clinical application scenarios of 3D printing in treating heart diseases. We also discuss the limitations and clinically unmet needs of 3D printing in this context.

scholarly journals Three-Dimensional Printing of Hydroxyapatite Composites for Biomedical Application

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 353
Author(s):  
Yanting Han ◽  
Qianqian Wei ◽  
Pengbo Chang ◽  
Kehui Hu ◽  
Oseweuba Valentine Okoro ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
3D Printing ◽  
Biomedical Application ◽  
Three Dimensional ◽  
Antibacterial Properties ◽  
Natural Polymers ◽  
Three Dimensional Printing ◽  
3D Printed ◽  
Dental Applications ◽  
Hard Tissue Engineering

Hydroxyapatite (HA) and HA-based nanocomposites have been recognized as ideal biomaterials in hard tissue engineering because of their compositional similarity to bioapatite. However, the traditional HA-based nanocomposites fabrication techniques still limit the utilization of HA in bone, cartilage, dental, applications, and other fields. In recent years, three-dimensional (3D) printing has been shown to provide a fast, precise, controllable, and scalable fabrication approach for the synthesis of HA-based scaffolds. This review therefore explores available 3D printing technologies for the preparation of porous HA-based nanocomposites. In the present review, different 3D printed HA-based scaffolds composited with natural polymers and/or synthetic polymers are discussed. Furthermore, the desired properties of HA-based composites via 3D printing such as porosity, mechanical properties, biodegradability, and antibacterial properties are extensively explored. Lastly, the applications and the next generation of HA-based nanocomposites for tissue engineering are discussed.

scholarly journals Three-dimensionally printed polycaprolactone/multicomponent bioactive glass scaffolds for potential application in bone tissue engineering

2020 ◽  
Vol 6 (1) ◽  
pp. 57-69
Author(s):  
Amirhosein Fathi ◽  
Farzad Kermani ◽  
Aliasghar Behnamghader ◽  
Sara Banijamali ◽  
Masoud Mozafari ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
3D Printing ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Three Dimensional ◽  
Layer By Layer ◽  
Composite Scaffolds ◽  
3D Printed ◽  
Co Doped

AbstractOver the last years, three-dimensional (3D) printing has been successfully applied to produce suitable substitutes for treating bone defects. In this work, 3D printed composite scaffolds of polycaprolactone (PCL) and strontium (Sr)- and cobalt (Co)-doped multi-component melt-derived bioactive glasses (BGs) were prepared for bone tissue engineering strategies. For this purpose, 30% of as-prepared BG particles (size <38 μm) were incorporated into PCL, and then the obtained composite mix was introduced into a 3D printing machine to fabricate layer-by-layer porous structures with the size of 12 × 12 × 2 mm3.The scaffolds were fully characterized through a series of physico-chemical and biological assays. Adding the BGs to PCL led to an improvement in the compressive strength of the fabricated scaffolds and increased their hydrophilicity. Furthermore, the PCL/BG scaffolds showed apatite-forming ability (i.e., bioactivity behavior) after being immersed in simulated body fluid (SBF). The in vitro cellular examinations revealed the cytocompatibility of the scaffolds and confirmed them as suitable substrates for the adhesion and proliferation of MG-63 osteosarcoma cells. In conclusion, 3D printed composite scaffolds made of PCL and Sr- and Co-doped BGs might be potentially-beneficial bone replacements, and the achieved results motivate further research on these materials.

scholarly journals 3D printing of a bio-based ink made of cross-linked cellulose nanofibrils with various metal cations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. Benedikt Mietner ◽  
Xuehe Jiang ◽  
Ulrica Edlund ◽  
Bodo Saake ◽  
Julien R. G. Navarro
Keyword(s):  
3D Printing ◽  
Divalent Cations ◽  
Cellulose Nanofibrils ◽  
Three Dimensional ◽  
Metal Cations ◽  
Cross Link ◽  
Cellulose Pulp ◽  
Freeze Dried ◽  
3D Printed ◽  
Metallic Cations

AbstractIn this work, we present an approach to cross-link cellulose nanofibrils (CNFs) with various metallic cations (Fe3+, Al3+, Ca2+, and Mg2+) to produce inks suitable for three-dimensional (3D) printing application. The printability of each hydrogel ink was evaluated, and several parameters such as the optimal ratio of Mn+:TOCNF:H2O were discussed. CNF suspensions were produced by mechanical disintegration of cellulose pulp with a microfluidizer and then oxidized with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). Finally, metal cations were introduced to the deprotonated TEMPO-oxidized CNF (TOCNF) suspension to cross-link the nanofibrils and form the corresponding hydrogels. The performances of each gel-ink were evaluated by rheological measurements and 3D printing. Only the gels incorporated with divalent cations Ca2+ and Mg2+ were suitable for 3D printing. The 3D printed structures were freeze-dried and characterized with Fourier transform infrared spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). The better interaction of the TOCNFs with the divalent metallic cations in terms of printability, the viscoelastic properties of the inks, and the variation trends owing to various metal cations and ratios are discussed.

A review on the role of 3D printing in the fight against COVID-19: safety and challenges

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sapam Ningthemba Singh ◽  
Vavilada Satya Swamy Venkatesh ◽  
Ashish Bhalchandra Deoghare
Keyword(s):  
Supply Chain ◽  
3D Printing ◽  
Three Dimensional ◽  
Content Type ◽  
Medical Supplies ◽  
Future Challenges ◽  
Safety And Reliability ◽  
3D Printed ◽  
Comprehensive Study

Purpose During the COVID-19 pandemic, the three-dimensional (3D) printing community is actively participating to address the supply chain gap of essential medical supplies such as face masks, face shields, door adapters, test swabs and ventilator valves. This paper aims to present a comprehensive study on the role of 3D printing during the coronavirus (COVID-19) pandemic, its safety and its challenges. Design/methodology/approach This review paper focuses on the applications of 3D printing in the fight against COVID-19 along with the safety and challenges associated with 3D printing to fight COVID-19. The literature presented in this paper is collected from the journal indexing engines including Scopus, Google Scholar, ResearchGate, PubMed, Web of Science, etc. The main keywords used for searches were 3D printing COVID-19, Safety of 3D printed parts, Sustainability of 3D printing, etc. Further possible iterations of the keywords were used to collect the literature. Findings The applications of 3D printing in the fight against COVID-19 are 3D printed face masks, shields, ventilator valves, test swabs, drug deliveries and hands-free door adapters. As most of these measures are implemented hastily, the safety and reliability of these parts often lacked approval. The safety concerns include the safety of the printed parts, operators and secondary personnel such as the workers in material preparation and transportation. The future challenges include sustainability of the process, long term supply chain, intellectual property and royalty-free models, etc. Originality/value This paper presents a comprehensive study on the applications of 3D printing in the fight against COVID-19 with emphasis on the safety and challenges in it.

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

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.

Algorithm to Reduce Leading and Lagging in Conformal Direct-Print

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Morteza Vatani ◽  
Faez Alkadi ◽  
Jae-Won Choi
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
3D Model ◽  
Three Dimensional ◽  
Motion Direction ◽  
B Spline ◽  
And Topology ◽  
Printing System ◽  
3D Printed ◽  
Printed Patterns

A novel additive manufacturing algorithm was developed to increase the consistency of three-dimensional (3D) printed curvilinear or conformal patterns on freeform surfaces. The algorithm dynamically and locally compensates the nozzle location with respect to the pattern geometry, motion direction, and topology of the substrate to minimize lagging or leading during conformal printing. The printing algorithm was implemented in an existing 3D printing system that consists of an extrusion-based dispensing module and an XYZ-stage. A dispensing head is fixed on a Z-axis and moves vertically, while the substrate is installed on an XY-stage and moves in the x–y plane. The printing algorithm approximates the printed pattern using nonuniform rational B-spline (NURBS) curves translated directly from a 3D model. Results showed that the proposed printing algorithm increases the consistency in the width of the printed patterns. It is envisioned that the proposed algorithm can facilitate nonplanar 3D printing using common and commercially available Cartesian-type 3D printing systems.

scholarly journals Off-Axis Diffractive Optics for Compact Terahertz Detection Setup

2020 ◽  
Vol 10 (23) ◽  
pp. 8594
Author(s):  
Paweł Komorowski ◽  
Mateusz Surma ◽  
Michał Walczakowski ◽  
Przemysław Zagrajek ◽  
Agnieszka Siemion
Keyword(s):  
3D Printing ◽  
Small Volume ◽  
Optical Element ◽  
Structure Design ◽  
Thz Radiation ◽  
Direct Printing ◽  
Terahertz Detection ◽  
3D Printed ◽  
Printing Techniques ◽  
Optical Structure

Medical and many other applications require small-volume setups enabling terahertz imaging. Therefore, we aim to develop a device for the in-reflection examination of the samples. Thus, in this article, we focus on the diffractive elements for efficient redirection and focusing of the THz radiation. A terahertz diffractive optical structure has been designed, optimized, manufactured (using extrusion-based 3D printing) and tested. Two manufacturing methods have been used—direct printing of the structures from PA12, and casting of the paraffin structures out of 3D-printed molds. Also, the limitations of the off-axis focusing have been discussed. To increase the efficiency, an iterative algorithm has been proposed that optimizes off-axis structures to focus the radiation into small focal spots located far from the optical axis, at an angle of more than 30 degrees. Moreover, the application of higher-order kinoform structure design allowed the maintaining of the smallest details of the manufactured optical element, using 3D printing techniques.

scholarly journals A STUDY ON PLANNING AND PLATFORM FOR INTERACTIVE EXHIBITION OF SCIENTIFIC CULTURAL HERITAGE

2019 ◽  
Vol XLII-2/W15 ◽  
pp. 605-607
Author(s):  
Y. H. Jo ◽  
J. Kim ◽  
N. C. Cho ◽  
C. H. Lee ◽  
Y. H. Yun ◽  
...  
Keyword(s):  
3D Printing ◽  
Cultural Heritage ◽  
Three Dimensional ◽  
Conservation Science ◽  
Scientific Content ◽  
Projection Mapping ◽  
Digital Database ◽  
3D Effects ◽  
3D Printed ◽  
Bronze Mirrors

<p><strong>Abstract.</strong> This study has developed an experiential exhibition system of scientific cultural heritage through interactive projection mapping. A bronze mirror with fine linear design was selected as an exhibition subject considering the intuitiveness and responsiveness of research and development results. First, three-dimensional (3D) scanning was performed to construct a digital database of the original forms, and computer graphics-based 3D modeling was also performed to build exhibition materials and 3D printed objects. Furthermore, objective scenarios were created based on a traditional science experience, understanding the present bronze mirror, and processes of restoring the corroded original bronze mirror through modern conservation science. The technique selected to implement the scientific content of bronze mirror as media art in this study is interactive projection mapping. Moreover, a large 3D printing of bronze mirror was installed at the center of the exhibition space to allow users and all viewers to concurrently engage in scientific cultural heritage content. Simultaneous projection mapping on the front and rear of the printed bronze mirror model enhanced 3D effects and the immersion of the content. To construct an interactive space connecting the virtual and reality, ore, mold, bronze mirror replicas, 3D printing outputs, and cultural products used in the process of producing bronze mirrors were exhibited to make the exhibit more intuitive for visitors. This interactive projection mapping-based scientific and cultural exhibition of the bronze mirror is an experiential exhibition system which combines traditional science, modern conservation science, and future exhibition technology.</p>

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