Tailoring Cellular Auxetics for Wearable Applications With Multimaterial 3D Printing

2016 ◽  
Author(s):  
Krishna Kumar Saxena ◽  
Emilio P. Calius ◽  
Raj Das
Keyword(s):  
3D Printing ◽  
Impact Resistance ◽  
Interesting Property ◽  
Cellular Materials ◽  
Strain Sensitivity ◽  
Gradient Distribution ◽  
Mechanical Metamaterials ◽  
Potential Applications ◽  
Protection Devices ◽  
Impact Protection

The properties of cellular materials depend as much on their architecture as on their composition. Auxetic materials are a novel class of mechanical metamaterials which exhibit an interesting property of negative Poisson’s ratio by virtue of their architecture rather than composition. One of their most interesting aspects is their improved indentation resistance, impact resistance and fracture toughness. Thus, they have potential applications in wearable impact protection. The classical re-entrant structure has been a focus of research for many years because of its well established auxetic behaviour. However, the stiff re-entrant corners, buckling of struts, less strain sensitivity and limited cellular stiffness limit its applications in wearable impact protection devices. In this work, multi-material cellular designs are proposed which have the capability to fulfill the requirements for wearable impact protection devices. With the advancements in 3D printing, multi-material cellular designs can be realized in practice. Using Finite Elements approach, two-material and multi-material cellular designs are investigated. It was observed that introduction of material gradient/distribution in the cell provides a means to tailor auxetic behaviour, cellular stiffness and strain-sensitivity as per the specific requirement. The results will lead to a better understanding of tailoring auxeticity in cellular materials and will aid in the design of auxetic wearable impact protection devices which rely on auxeticity gradients and variable auxeticity as well.

scholarly journals Complex Geometry Strain Sensors Based on 3D Printed Nanocomposites: Spring, Three-Column Device and Footstep-Sensing Platform

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1106
Author(s):  
Alejandro Cortés ◽  
Xoan F. Sánchez-Romate ◽  
Alberto Jiménez-Suárez ◽  
Mónica Campo ◽  
Ali Esmaeili ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
3D Printing ◽  
Complex Geometry ◽  
Uv Light ◽  
Shielding Effect ◽  
Strain Sensitivity ◽  
Printing Technology ◽  
3D Printing Technology ◽  
Sensing Platform ◽  
Electromechanical Performance

Electromechanical sensing devices, based on resins doped with carbon nanotubes, were developed by digital light processing (DLP) 3D printing technology in order to increase design freedom and identify new future and innovative applications. The analysis of electromechanical properties was carried out on specific sensors manufactured by DLP 3D printing technology with complex geometries: a spring, a three-column device and a footstep-sensing platform based on the three-column device. All of them show a great sensitivity of the measured electrical resistance to the applied load and high cyclic reproducibility, demonstrating their versatility and applicability to be implemented in numerous items in our daily lives or in industrial devices. Different types of carbon nanotubes—single-walled, double-walled and multi-walled CNTs (SWCNTs, DWCNTs, MWCNTs)—were used to evaluate the effect of their morphology on electrical and electromechanical performance. SWCNT- and DWCNT-doped nanocomposites presented a higher Tg compared with MWCNT-doped nanocomposites due to a lower UV light shielding effect. This phenomenon also justifies the decrease of nanocomposite Tg with the increase of CNT content in every case. The electromechanical analysis reveals that SWCNT- and DWCNT-doped nanocomposites show a higher electromechanical performance than nanocomposites doped with MWCNTs, with a slight increment of strain sensitivity in tensile conditions, but also a significant strain sensitivity gain at bending conditions.

scholarly journals Additive Manufacturing of Biopolymers for Tissue Engineering and Regenerative Medicine: An Overview, Potential Applications, Advancements, and Trends

2021 ◽  
Vol 2021 ◽  
pp. 1-20 ◽  
Author(s):  
Dhinakaran Veeman ◽  
M. Swapna Sai ◽  
P. Sureshkumar ◽  
T. Jagadeesha ◽  
L. Natrayan ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Regenerative Medicine ◽  
Tissue Regeneration ◽  
Three Dimensional ◽  
Porous Scaffolds ◽  
Wide Range ◽  
Potential Applications ◽  
Pharmaceutical Industries

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.

Computational Study of Reinforcement Mechanisms of Cuttlefish Bone Inspired Structure for 3D Printing

2021 ◽  
Author(s):  
Brandon Bethers ◽  
Yang Yang
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Computational Study ◽  
High Energy ◽  
Simulation Software ◽  
Support Structures ◽  
Common Support ◽  
Potential Applications ◽  
Manufacturing Techniques ◽  
Traditional Manufacturing

Abstract Cuttlebone, the internal shell structure of a cuttlefish, presents a unique labyrinthian wall-septa design that promotes high energy absorption, porosity, and damage tolerance. This structure offers us an inspiration for the design of lightweight and strong structures for potential applications in mechanical, aerospace and biomedical engineering. However, the complexity of the cuttlebones structural design makes its fabrication by traditional manufacturing techniques not feasible. The advances in additive manufacturing (3D printing) make highly complex structures like cuttlebone possible to manufacture. In this work, the authors sought to establish comparative data between cuttlebone structures and some common support structures used in additive manufacturing. The structures compared to cuttlebone in this work include the cubic, honeycomb and triangular support structures. This was accomplished by using CAD modeling and simulation software. This study found that the cuttlefish structures had higher average stress values than the others but similar average strain values. This leads to a higher modulus of elasticity for the cuttlebone structures. The data suggests that further research into cuttlebone structures could produce future designs that improve upon the current well-established additive manufacturing support structures. Further study will be performed for the 3D printing of cuttlebone inspired structures by using various types of materials, such as soft and rigid polymers, functional ceramics, composites, and metals.

3D printing of cellular materials for advanced electrochemical energy storage and conversion

Nanoscale ◽  
2020 ◽  
Vol 12 (14) ◽  
pp. 7416-7432 ◽  
Author(s):  
Xiaocong Tian ◽  
Kun Zhou
Keyword(s):  
Energy Storage ◽  
3D Printing ◽  
Cellular Materials ◽  
Electrochemical Energy Storage ◽  
Energy Storage And Conversion ◽  
Comprehensive Overview ◽  
3D Printed ◽  
Electrochemical Energy

This article provides a comprehensive overview of 3D-printed cellular materials for advanced electrochemical energy storage and conversion applications.

scholarly journals Design and Characterization of Sodium Alginate and Poly(vinyl) Alcohol Hydrogels for Enhanced Skin Delivery of Quercetin

Pharmaceutics ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1149
Author(s):  
Ludovico Esposito ◽  
Ana Isabel Barbosa ◽  
Tânia Moniz ◽  
Sofia Costa Lima ◽  
Paulo Costa ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Sodium Alginate ◽  
Vinyl Alcohol ◽  
Fruits And Vegetables ◽  
Radical Scavenging ◽  
Entrapment Efficiency ◽  
Interesting Property ◽  
Poly Vinyl Alcohol ◽  
Skin Delivery ◽  
Potential Applications

Nature has led to the discovery of biopolymers with noteworthy pharmaceutical applications. Blended biopolymers have demonstrated promising characteristics when compared with their individual counterparts. Sodium alginate (SA) is a marine polymer that has demonstrated the ability to form hydrogels, an interesting property for the development of cutaneous formulations. Predicting the good performance of blended biopolymers, a novel series of hybrid hydrogels based on SA and poly(vinyl) alcohol (PVA) were prepared. Quercetin, a natural polyphenolic flavonoid commonly found in fruits and vegetables, is widely known for its strong anti-inflammatory and antioxidant activity, thus with potential applications against melanoma, dermatitis, psoriasis, and skin ageing. Here, hydrogels were produced at different ratios of SA and PVA. The surface morphology, structure, interaction of polymers, the capacity to absorb water and the entrapment efficiency of quercetin were evaluated for the blended hydrogels. Targeting the cutaneous application of the formulations, the rheological properties of all unloaded and quercetin-loaded hydrogels revealed pseudoplastic behavior, evidence of non-thixotropy, good resistance to deformation, and profile maintenance with temperatures ranging from 20 °C up to 40 °C. The incorporation of quercetin in the hydrogel retained its antioxidant activity, confirmed by radical scavenging assays (ABTS and DPPH). The permeability of quercetin through the skin showed different penetration/permeation profiles according to the hydrogel’s blend. This behavior will allow the selection of SA-PVA at 2/1 ratio for a local and prolonged skin effect, making the use of these hydrogels a good solution to consider for the treatment of skin ageing and inflammation.

scholarly journals Developing Fall-impact Protection Pad with 3D Mesh Curved Surface Structure using 3D Printing Technology

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1800 ◽  
Author(s):  
Park ◽  
Lee
Keyword(s):  
3D Printing ◽  
Human Body ◽  
Curved Surface ◽  
Printing Technology ◽  
Mesh Structure ◽  
3D Printing Technology ◽  
Spacer Fabric ◽  
Impact Protection ◽  
Scan Data ◽  
The Impact

In this study, we present the development of fall-impact protection pads for elderly people using three-dimensional (3D) printing technology. To develop fall-impact protection clothing, it is important to maintain the functionality of the protection pad while ensuring that its effectiveness and appearance remain optimal in the process of inserting it. Therefore, this study explores the benefit of exploiting 3D scan data of the human body using 3D printing technology to develop a fall-impact protection pad that is highly suited to the human body shape. The purpose of this study was to present a 3D modeling process for creating curved protective pads comprising a hexagonal mesh with a spacer fabric structure and to verify the impact protection performance by printing curved pads. To this end, we set up a section that includes pads in the 3D human body scan data and extracted body surface information to be applied in the generation of the pad surface. The sheet-shaped hexagonal mesh structure was cut and separated according to the pad outline, and then deformed according to the curved surface of the human body. The pads were printed, and their protection performance was evaluated; a 79.2–81.8% reduction in impact force was observed compared to similar cases in which the pads were not used.

scholarly journals 3D-Printed Biopolymers for Tissue Engineering Application

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Xiaoming Li ◽  
Rongrong Cui ◽  
Lianwen Sun ◽  
Katerina E. Aifantis ◽  
Yubo Fan ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
3D Printing ◽  
Three Dimensional ◽  
Engineering Application ◽  
Tissue Engineering Application ◽  
Printing Technology ◽  
3D Printing Technology ◽  
Potential Applications ◽  
3D Printed ◽  
Dimensional Object

3D printing technology has recently gained substantial interest for potential applications in tissue engineering due to the ability of making a three-dimensional object of virtually any shape from a digital model. 3D-printed biopolymers, which combine the 3D printing technology and biopolymers, have shown great potential in tissue engineering applications and are receiving significant attention, which has resulted in the development of numerous research programs regarding the material systems which are available for 3D printing. This review focuses on recent advances in the development of biopolymer materials, including natural biopolymer-based materials and synthetic biopolymer-based materials prepared using 3D printing technology, and some future challenges and applications of this technology are discussed.

scholarly journals Rapid Fabrication of MgNH4PO4·H2O/SrHPO4 Porous Composite Scaffolds with Improved Radiopacity via 3D Printing Process

Biomedicines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1138
Author(s):  
Xiaofeng Cao ◽  
Wufei Ge ◽  
Yihu Wang ◽  
Ming Ma ◽  
Ying Wang ◽  
...  
Keyword(s):  
3D Printing ◽  
Bone Repair ◽  
Magnesium Phosphate ◽  
Porous Composite ◽  
Composite Scaffolds ◽  
X Ray ◽  
P Elements ◽  
Cellular Attachment ◽  
Potential Applications

Although bone repair scaffolds are required to possess high radiopacity to be distinguished from natural bone tissues in clinical applications, the intrinsic radiopacity of them is usually insufficient. For improving the radiopacity, combining X-ray contrast agents with bone repair scaffolds is an effective method. In the present research, MgNH4PO4·H2O/SrHPO4 3D porous composite scaffolds with improved radiopacity were fabricated via the 3D printing technique. Here, SrHPO4 was firstly used as a radiopaque agent to improve the radiopacity of magnesium phosphate scaffolds. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) were used to characterize the phases, morphologies, and element compositions of the 3D porous composite scaffolds. The radiography image showed that greater SrHPO4 contents corresponded to higher radiopacity. When the SrHPO4 content reached 9.34%, the radiopacity of the composite scaffolds was equal to that of a 6.8 mm Al ladder. The porosity and in vitro degradation of the porous composite scaffolds were studied in detail. The results show that magnesium phosphate scaffolds with various Sr contents could sustainably degrade and release the Mg, Sr, and P elements during the experiment period of 28 days. In addition, the cytotoxicity on MC3T3-E1 osteoblast precursor cells was evaluated, and the results show that the porous composite scaffolds with a SrHPO4 content of 9.34% possessed superior cytocompatibility compared to that of the pure MgNH4PO4·H2O scaffolds when the extract concentration was 0.1 g/mL. Cell adhesion experiments showed that all of the scaffolds could support MC3T3-E1 cellular attachment well. This research indicates that MgNH4PO4·H2O/SrHPO4 porous composite scaffolds have potential applications in the bone repair fields.

scholarly journals Recycled Tire Rubber in Additive Manufacturing: Selective Laser Sintering for Polymer-Ground Rubber Composites

2021 ◽  
Vol 11 (18) ◽  
pp. 8778
Author(s):  
Antoniya Toncheva ◽  
Loïc Brison ◽  
Philippe Dubois ◽  
Fouad Laoutid
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Thermoplastic Polyurethane ◽  
Selective Laser Sintering ◽  
Morphological Characteristics ◽  
Laser Sintering ◽  
Industrial Applications ◽  
Tire Rubber ◽  
Abrasive Resistance ◽  
Potential Applications

Natural and synthetic rubber is gaining increased interest in various industrial applications and daily life sectors (automotive industry, acoustic and electrical isolators, adhesives, impermeable surfaces, and others) due to its remarkable physicomechanical properties, excellent durability, and abrasive resistance. These great characteristics are accompanied by some recycling difficulties of the final products, particularly originated from the tire waste rubber industry. In this study, recycled tire rubber was incorporated in polymer matrices using selective laser sintering as 3D printing technology. Two polymers were used-polyamide and thermoplastic polyurethane, for their rigid and elastomeric properties, respectively. Polymer composites containing various tire powder amounts, up to 40 wt.%, were prepared by physical blending. The final materials’ morphological characteristics, mechanical properties, and thermal stability were evaluated. The proposed ambitious additive manufacturing approach looked over also some of the major aspects to be considered during the 3D printing procedure. In addition, examples of printed prototypes with potential applications were also proposed revealing the potential of the recycled tire rubber-loaded composites.

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