Colloidal Oxide Nanoparticle Inks for Micrometer-Resolution Additive Manufacturing of Three-Dimensional Gas Sensors

2022 ◽  
Author(s):  
Hehao Chen ◽  
Xinjie Min ◽  
Yue Hui ◽  
Weiwei Qin ◽  
Boyu Zhang ◽  
...  

Micrometer-resolution 3D printing of functional oxides is of growing importance for the fabrication of micro-electromechanical systems (MEMS) with customized 3D geometries. Comparing to conventional microfabrication methods, additive manufacturing presents new...

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaoyu Zhao ◽  
Ye Zhao ◽  
Ming-De Li ◽  
Zhong’an Li ◽  
Haiyan Peng ◽  
...  

AbstractPhotopolymerization-based three-dimensional (3D) printing can enable customized manufacturing that is difficult to achieve through other traditional means. Nevertheless, it remains challenging to achieve efficient 3D printing due to the compromise between print speed and resolution. Herein, we report an efficient 3D printing approach based on the photooxidation of ketocoumarin that functions as the photosensitizer during photopolymerization, which can simultaneously deliver high print speed (5.1 cm h−1) and high print resolution (23 μm) on a common 3D printer. Mechanistically, the initiating radical and deethylated ketocoumarin are both generated upon visible light exposure, with the former giving rise to rapid photopolymerization and high print speed while the latter ensuring high print resolution by confining the light penetration. By comparison, the printed feature is hard to identify when the ketocoumarin encounters photoreduction due to the increased lateral photopolymerization. The proposed approach here provides a viable solution towards efficient additive manufacturing by controlling the photoreaction of photosensitizers during photopolymerization.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3149
Author(s):  
Angelika Zaszczyńska ◽  
Maryla Moczulska-Heljak ◽  
Arkadiusz Gradys ◽  
Paweł Sajkiewicz

Tissue engineering (TE) scaffolds have enormous significance for the possibility of regeneration of complex tissue structures or even whole organs. Three-dimensional (3D) printing techniques allow fabricating TE scaffolds, having an extremely complex structure, in a repeatable and precise manner. Moreover, they enable the easy application of computer-assisted methods to TE scaffold design. The latest additive manufacturing techniques open up opportunities not otherwise available. This study aimed to summarize the state-of-art field of 3D printing techniques in applications for tissue engineering with a focus on the latest advancements. The following topics are discussed: systematics of the available 3D printing techniques applied for TE scaffold fabrication; overview of 3D printable biomaterials and advancements in 3D-printing-assisted tissue engineering.


Author(s):  
Morteza Vatani ◽  
Faez Alkadi ◽  
Jae-Won Choi

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.


2021 ◽  
Vol 2021 ◽  
pp. 1-20 ◽  
Author(s):  
Dhinakaran Veeman ◽  
M. Swapna Sai ◽  
P. Sureshkumar ◽  
T. Jagadeesha ◽  
L. Natrayan ◽  
...  

As a technique of producing fabric engineering scaffolds, three-dimensional (3D) printing has tremendous possibilities. 3D printing applications are restricted to a wide range of biomaterials in the field of regenerative medicine and tissue engineering. Due to their biocompatibility, bioactiveness, and biodegradability, biopolymers such as collagen, alginate, silk fibroin, chitosan, alginate, cellulose, and starch are used in a variety of fields, including the food, biomedical, regeneration, agriculture, packaging, and pharmaceutical industries. The benefits of producing 3D-printed scaffolds are many, including the capacity to produce complicated geometries, porosity, and multicell coculture and to take growth factors into account. In particular, the additional production of biopolymers offers new options to produce 3D structures and materials with specialised patterns and properties. In the realm of tissue engineering and regenerative medicine (TERM), important progress has been accomplished; now, several state-of-the-art techniques are used to produce porous scaffolds for organ or tissue regeneration to be suited for tissue technology. Natural biopolymeric materials are often better suited for designing and manufacturing healing equipment than temporary implants and tissue regeneration materials owing to its appropriate properties and biocompatibility. The review focuses on the additive manufacturing of biopolymers with significant changes, advancements, trends, and developments in regenerative medicine and tissue engineering with potential applications.


Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4534 ◽  
Author(s):  
Elżbieta Bogdan ◽  
Piotr Michorczyk

This paper describes the process of additive manufacturing and a selection of three-dimensional (3D) printing methods which have applications in chemical synthesis, specifically for the production of monolithic catalysts. A review was conducted on reference literature for 3D printing applications in the field of catalysis. It was proven that 3D printing is a promising production method for catalysts.


Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 796 ◽  
Author(s):  
Honghui Chu ◽  
Wenguang Yang ◽  
Lujing Sun ◽  
Shuxiang Cai ◽  
Rendi Yang ◽  
...  

Since the late 1980s, additive manufacturing (AM), commonly known as three-dimensional (3D) printing, has been gradually popularized. However, the microstructures fabricated using 3D printing is static. To overcome this challenge, four-dimensional (4D) printing which defined as fabricating a complex spontaneous structure that changes with time respond in an intended manner to external stimuli. 4D printing originates in 3D printing, but beyond 3D printing. Although 4D printing is mainly based on 3D printing and become an branch of additive manufacturing, the fabricated objects are no longer static and can be transformed into complex structures by changing the size, shape, property and functionality under external stimuli, which makes 3D printing alive. Herein, recent major progresses in 4D printing are reviewed, including AM technologies for 4D printing, stimulation method, materials and applications. In addition, the current challenges and future prospects of 4D printing were highlighted.


Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2900
Author(s):  
Alyaa Mohammed ◽  
Nihad Tareq Khshain Al-Saadi

One of the considerable challenges in the design of cementitious mixtures for additive manufacturing/three-dimensional (3D) printing applications is achieving both suitable fresh properties and significant mechanical strengths. This paper presents the use of graphene oxide (GO) as a promising nano reinforcement material with the potential to improve the printing feasibility and quality of a 3D printed cementitious matrix. Additionally, in this study, a viscosity modifying agent (VMA) was employed as a chemical additive to attain the required consistency and flow. The printed mixture was fabricated using various cementitious materials and waste materials. This study investigated the impact of GO and VMA on the enhancement of the 3D printing of cementitious composites through several tests. A flow test was conducted using the flow table test. The results showed a high fluidity and practical consistency, which are essential for nozzle pumping and accurateness in printed shapes. Furthermore, the bleeding test showed minimal bleeding up to hardening, and a considerable self-cleaning ability was noted during handling when conducting examinations of fresh properties. For hardened properties, the mechanical strengths were exceptionally high, especially at early ages, which is crucial for the stability of sequence layers of printed composites. The tensile strengths were 3.77, 10.5, 13.35, and 18.83 MPa at 1, 3, 7, and 28 days, respectively, and the compressive strengths were 25.1, 68.4, 85.6, and 125.4 MPa at 1, 3, 7, and 28 days, respectively. The test results showed the effectiveness of the fabricated cementitious mixture design method for meeting the requirements for 3D concrete printing applications.


2021 ◽  
Author(s):  
Shadpour Mallakpour ◽  
Fariba Sirous ◽  
Chaudhery Mustansar Hussain

In recent years, additive manufacturing, or in other words three-dimensional (3D) printing technology has rapidly become one of the hot topics in the world. Among the vast majority of materials,...


Author(s):  
Ranjit Barua ◽  
Sudipto Datta ◽  
Amit Roychowdhury ◽  
Pallab Datta

Three-dimensional or 3D printing technology is a growing interest in medical fields like tissue engineering, dental, drug delivery, prosthetics, and implants. It is also known as the additive manufacturing (AM) process because the objects are done by extruding or depositing the material layer by layer, and the material may be like biomaterials, plastics, living cells, or powder ceramics. Specially in the medical field, this new technology has importance rewards in contrast with conventional technologies, such as the capability to fabricate patient-explicit difficult components, desire scaffolds for tissue engineering, and proper material consumption. In this chapter, different types of additive manufacturing (AM) techniques are described that are applied in the medical field, especially in community health and precision medicine.


2018 ◽  
Vol 24 (8) ◽  
pp. 1265-1271 ◽  
Author(s):  
Aimin Tang ◽  
Qinwen Wang ◽  
Shan Zhao ◽  
Wangyu Liu

Purpose Nanocellulose is characterised by favourable biocompatibility, degradability, nanostructure effect, high modulus and high tensile strength and has been widely applied in various fields. The current research in the field of new nanocellulose materials mainly focuses on the hydrogel, aerogel and the tissue engineering scaffold. All of these are three-dimensional (3D) porous materials, but conventional manufacturing technology fails to realise precise control. Therefore, the method of preparing structural materials using 3D printing and adopting the nanocellulose as the 3D printing material has been proposed. Then, how to realise 3D printing of nanocellulose is the problem that should be solved. Design/methodology/approach By adding the photosensitive component polyethyleneglycol diacrylate (PEGDA) in the aqueous dispersion system of nanocellulose, the nanocellulose was endowed with photosensitivity. Then, nanocellulose/PEGDA hydrogels were prepared by the additive manufacturing of nanocellulose through light curing. Findings The results showed that the nanocellulose/PEGDA hydrogels had a uniform shape and a controllable structure. The nanocellulose supported the scaffold structure in the hydrogels. Prepared with 1.8 per cent nanocellulose through 40 s of light curing, the nanocellulose/PEGDA hydrogels had a maximum compression modulus of 0.91 MPa. The equilibrium swelling ratio of the nanocellulose/PEGDA hydrogel prepared with 1.8 per cent nanocellulose was 13.56, which increased by 44 per cent compared with that of the PEGDA hydrogel without nanocellulose. Originality/value The paper proposed a method for rapidly prototyping the nanocellulose with expected properties, which provided a theoretical basis and technological reference for the 3D additive manufacturing of nanocellulose 3D structure materials with a controlled accurate architecture.


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