Patterned Magnetorheological Elastomer Developed by 3D Printing

2018 ◽  
Vol 939 ◽  
pp. 147-152 ◽  
Author(s):  
Anil K. Bastola ◽  
Milan Paudel ◽  
Lin Li

This article delineates the characterization of the 3D printed MR elastomer through a forced vibration technique in the squeeze mode of operation. An anisotropic hybrid magnetorheological (MR) elastomer is developed via 3D printing. The 3D printed MR elastomer consists of three different materials; magnetic particles, magnetic particles carrier fluid, and an elastomer. MR fluid filaments are encapsulated layer-by-layer within the elastomer matrix using a 3D printer. When a moderately strong magnetic field is applied, the 3D printed MR elastomer changes its elastic and damping properties. The hybrid 3D printed MR elastomer also shows an anisotropic behavior when the direction of the magnetic field is changed with respect to the orientation of the printed filaments. The relative MR effect is higher when the applied magnetic field is parallel to the orientation of the printed filaments. The maximum change in the stiffness is observed to be 65.2% when a magnetic field of 500 mT is applied to the MR elastomer system. This result shows that the new method, 3D printing could produce anisotropic hybrid MR elastomers or possibly other types.

Author(s):  
Anil K. Bastola ◽  
Milan Paudel ◽  
Lin Li

In this study, 3D printed magnetorheological (MR) elastomer has been characterized through a force vibration testing. The 3D printed MR elastomer is a composite consisting three different materials, magnetic particles and two different elastomers. The MR elastomers were printed layer-by-layer by encapsulating MR fluid within the polymeric elastomer and then allowed to cure at room temperature. The 3D printing allowed to print various patterns of magnetic particles within the elastomeric matrix. In the presence of an external magnetic field, both elastic and damping properties of the 3D printed MR elastomers were changed. Natural frequency, stiffness, damping ratio, damping coefficient, and shear modulus were increased with increasing magnetic field. For the single degree-of-freedoms system, shear mode MR elastomers suppressed the transmitted vibration amplitude up to 31.4% when the magnetic field was 550 mT. The results showed that the 3D printed MR elastomer could be used as a tunable spring element for vibration absorption or isolation applications. However, further optimization of the magnetic particles’ configurations should be performed to obtain the higher MR effect.


2019 ◽  
Vol 31 (3) ◽  
pp. 377-388 ◽  
Author(s):  
AK Bastola ◽  
M Paudel ◽  
L Li

This article presents the development of line-patterned magnetorheological elastomers via 3D printing and their magnetorheological characterization. Herein, we consider five different patterns of magnetorheological fluid filaments that are printed and encapsulated within the elastomer matrix. The 3D-printed magnetorheological elastomers could represent the conventional isotropic and anisotropic magnetorheological elastomers. First, the effect of patterning the magnetorheological fluid filaments and the effect of change in the direction of the magnetic field is studied for all five patterns. Thereafter, the dynamic properties of 3D-printed magnetorheological elastomers under uniaxial deformation are presented. Magnetorheological effect shown by 3D-printed magnetorheological elastomers was found to be depended on the printed patterns as well as the direction of the applied magnetic field. This result showed that the 3D printing method has the potential to produce anisotropic magnetorheological elastomers or unique configuration of magnetic particles within the elastomer matrix. The dynamic testing showed that the storage modulus of 3D-printed magnetorheological elastomers is increased with increasing frequency and decreased with increasing strain amplitude, which signifies that the 3D-printed hybrid magnetorheological elastomers are also viscoelastic materials and the properties are magnetic field dependent as that of current magnetorheological elastomers.


2020 ◽  
Vol 6 (1) ◽  
pp. 57-69
Author(s):  
Amirhosein Fathi ◽  
Farzad Kermani ◽  
Aliasghar Behnamghader ◽  
Sara Banijamali ◽  
Masoud Mozafari ◽  
...  

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.


Author(s):  
Azar Maalouf ◽  
Ronan Gingat ◽  
Vincent Laur

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.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Remmi Danae Baker ◽  
Thomas Montenegro-Johnson ◽  
Anton D. Sediako ◽  
Murray J. Thomson ◽  
Ayusman Sen ◽  
...  

Abstract Through billions of years of evolution, microorganisms mastered unique swimming behaviors to thrive in complex fluid environments. Limitations in nanofabrication have thus far hindered the ability to design and program synthetic swimmers with the same abilities. Here we encode multi-behavioral responses in microscopic self-propelled tori using nanoscale 3D printing. We show experimentally and theoretically that the tori continuously transition between two primary swimming modes in response to a magnetic field. The tori also manipulated and transported other artificial swimmers, bimetallic nanorods, as well as passive colloidal particles. In the first behavioral mode, the tori accumulated and transported nanorods; in the second mode, nanorods aligned along the toriʼs self-generated streamlines. Our results indicate that such shape-programmed microswimmers have a potential to manipulate biological active matter, e.g. bacteria or cells.


2019 ◽  
Vol 24 (42) ◽  
pp. 5039-5048 ◽  
Author(s):  
Sabna Kotta ◽  
Anroop Nair ◽  
Nimer Alsabeelah

Background: 3D printing technology is a new chapter in pharmaceutical manufacturing and has gained vast interest in the recent past as it offers significant advantages over traditional pharmaceutical processes. Advances in technologies can lead to the design of suitable 3D printing device capable of producing formulations with intended drug release. Methods: This review summarizes the applications of 3D printing technology in various drug delivery systems. The applications are well arranged in different sections like uses in personalized drug dosing, complex drugrelease profiles, personalized topical treatment devices, novel dosage forms and drug delivery devices and 3D printed polypills. Results: This niche technology seems to be a transformative tool with more flexibility in pharmaceutical manufacturing. Typically, 3D printing is a layer-by-layer process having the ability to fabricate 3D formulations by depositing the product components by digital control. This additive manufacturing process can provide tailored and individualized dosing for treatment of patients different backgrounds with varied customs and metabolism pattern. In addition, this printing technology has the capacity for dispensing low volumes with accuracy along with accurate spatial control for customized drug delivery. After the FDA approval of first 3D printed tablet Spritam, the 3D printing technology is extensively explored in the arena of drug delivery. Conclusion: There is enormous scope for this promising technology in designing various delivery systems and provides customized patient-compatible formulations with polypills. The future of this technology will rely on its prospective to provide 3D printing systems capable of manufacturing personalized doses. In nutshell, the 3D approach is likely to revolutionize drug delivery systems to a new level, though need time to evolve.


2014 ◽  
Vol 896 ◽  
pp. 444-447
Author(s):  
Yi Hua Fan ◽  
Liao Yong Lou ◽  
Yu Ming Chen

The Phenomenon of a Magnetic Controlled Ferrofluid Flow in the Flat Plate Laminar Flow System is Discussed in this Paper. the Ferrofluid Flow is One Kind of Colloid Mixture, which is Composited by the Magnetic Particles, Carrier Fluid and Surfactant. its Motion is Followed the Fluid Dynamics and can be Controlled by a Magnetic Field. from the Theoretic Analysis and the Experimental Test, the Coefficient of Viscosity of the Ferrofluid Flow will be Affected by the Magnetic Field. Thus, an Experimental Rig is Built to Test the Influences of the Gap of the Plate and the Strength and Direction of the Magnetic Field for Several Ferrofluid Flows with Different Dividing Rates of Volume. Experimental Results Showed that the Coefficient of Viscosity of the Ferrofluid Flow is Almost Not Upgrading in a Wide Gap Condition by the Magnetic Field, but as the Gap is Smaller, the Coefficient of Viscosity will be Promoted Obviously. Furthermore, Enhancing the Magnetic Field, it will be Increase the Coefficient of Viscosity of the Ferrofluid Flow. from the Experimental Results, the Relationship of the Magnetic Field, Coefficient of Viscosity of Ferrofluid Flow and the Carrier Fluid can be Confirmed.


Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3162
Author(s):  
Maria A. Morales ◽  
Alejandro Maranon ◽  
Camilo Hernandez ◽  
Alicia Porras

Natural filler-based composites are an environmentally friendly and potentially sustainable alternative to synthetic or plastic counterparts. Recycling polymers and using agro-industrial wastes are measures that help to achieve a circular economy. Thus, this work presents the development and characterization of a 3D printing filament based on recycled polypropylene and cocoa bean shells, which has not been explored yet. The obtained composites were thermally and physically characterized. In addition, the warping effect, mechanical, and morphological analyses were performed on 3D printed specimens. Thermal analysis exhibited decreased thermal stability when cacao bean shell (CBS) particles were added due to their lignocellulosic content. A reduction in both melting enthalpy and crystallinity percentage was identified. This is caused by the increase in the amorphous structures present in the hemicellulose and lignin of the CBS. Mechanical tests showed high dependence of the mechanical properties on the 3D printing raster angle. Tensile strength increased when a raster angle of 0° was used, compared to specimens printed at 90°, due to the load direction. Tensile strength and fracture strain were improved with CBS addition in specimens printed at 90°, and better bonding between adjacent layers was achieved. Electron microscope images identified particle fracture, filler-matrix debonding, and matrix breakage as the central failure mechanisms. These failure mechanisms are attributed to the poor interfacial bonding between the CBS particles and the matrix, which reduced the tensile properties of specimens printed at 0°. On the other hand, the printing process showed that cocoa bean shell particles reduced by 67% the characteristic warping effect of recycled polypropylene during 3D printing, which is advantageous for 3D printing applications of the rPP. Thereby, potential sustainable natural filler composite filaments for 3D printing applications with low density and low cost can be developed, adding value to agro-industrial and plastic wastes.


BioTechniques ◽  
2021 ◽  
Author(s):  
Vedika J Shenoy ◽  
Chelsea ER Edwards ◽  
Matthew E Helgeson ◽  
Megan T Valentine

3D printing holds potential as a faster, cheaper alternative compared with traditional photolithography for the fabrication of microfluidic devices by replica molding. However, the influence of printing resolution and quality on device design and performance has yet to receive detailed study. Here, we investigate the use of 3D-printed molds to create staggered herringbone mixers (SHMs) with feature sizes ranging from ∼100 to 500 μm. We provide guidelines for printer calibration to ensure accurate printing at these length scales and quantify the impacts of print variability on SHM performance. We show that SHMs produced by 3D printing generate well-mixed output streams across devices with variable heights and defects, demonstrating that 3D printing is suitable and advantageous for low-cost, high-throughput SHM manufacturing.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2456
Author(s):  
Demei Lee ◽  
Guan-Yu Wu

Three-dimensional (3D) printing is a manufacturing technology which creates three-dimensional objects layer-by-layer or drop-by-drop with minimal material waste. Despite the fact that 3D printing is a versatile and adaptable process and has advantages in establishing complex and net-shaped structures over conventional manufacturing methods, the challenge remains in identifying the optimal parameters for the 3D printing process. This study investigated the influence of processing parameters on the mechanical properties of Fused Deposition Modelling (FDM)-printed carbon fiber-filled polylactide (CFR-PLA) composites by employing an orthogonal array model. After printing, the tensile and impact strengths of the printed composites were measured, and the effects of different parameters on these strengths were examined. The experimental results indicate that 3D-printed CFR-PLA showed a rougher surface morphology than virgin PLA. For the variables selected in this analysis, bed temperature was identified as the most influential parameter on the tensile strength of CFR-PLA-printed parts, while bed temperature and print orientation were the key parameters affecting the impact strengths of printed composites. The 45° orientation printed parts also showed superior mechanical strengths than the 90° printed parts.


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