An official website of the United States government
One critical challenge for commercial products manufactured via material extrusion 3D printing is their inferior mechanical properties in comparison to injection molding; in particular, 3D printing leads to weaker properties perpendicular to the plane of the printed roads (z-direction). Here, rapid (≤20 s) post-processing of 3D printed carbon- poly(ether ether ketone) (PEEK) with microwaves is demonstrated to dramatically increase the modulus, such that the z-direction after microwave processing (2.7–3.8 GPa) exhibits a higher elastic modulus than the maximum in any direction for the as-printed part (2.3 GPa). Additionally, the stress at break in the z-orientation is increased by an order of magnitude by microwaves to slign with the stress for other print orientations in the as-printed state. The rapid heating and cooling by coupling of the microwave energy with the carbon filler in the PEEK does not increase the crystallinity of the PEEK, so the increased mechanical properties are attributed to improved interfaces between printed roads. This simple microwave post-processing enables large increases in the elastic modulus of the printed parts and can be tuned by the microwave power. As PEEK is generally difficult to print, these concepts can likely be applied to other commercial engineering plastic filaments that contain carbon or other fillers that are microwave active to rapidly post process 3D printed thermoplastics without requiring modification of the filament with selective placement of microwave absorbers. Additionally, these results demonstrate that the average crystallinity does not necessarily correlate with the strength of 3D printed semicrystalline plastics due to the importance of the details of the interface between adjacent printed roads.
more »
« less
A mindful introduction to 3D printing: Teaching students to maximize output while minimizing waste
This article showcases a lesson developed by the authors to be a mindful and engaging introduction to 3D printing that positions students to maximize the output of the 3D-printing process by reducing print failures and inefficiencies. The big idea for this lesson is to have students learn and apply the concepts behind designing for manufacturability through the additive manufacturing process. To do so, students will explore various 3D-printed designs and consider the concepts of what makes those designs good or bad. These concepts include print orientation, infill, layer height, and support. Students will then be challenged to apply their acquired knowledge by engaging in an engineering challenge to optimize the speed, quality, and efficiency of a 3D-printed product by appropriately adjusting print settings within slicing software—helping to ensure that students know how to take care in printing objects in a way that maximizes the output of the printing process while minimizing the waste of materials and other resources. At the end of the challenge, students will evaluate and share both the print settings and the final features of the printed products to illustrate and reaffirm their knowledge from the lesson as well as determine which student team achieved the most ideal results for the challenge.
more »
« less
- Award ID(s):
- 2044288
- PAR ID:
- 10569187
- Publisher / Repository:
- International Technology and Engineering Educators Association
- Date Published:
- Journal Name:
- Technology & Engineering Education Journal
- ISSN:
- https://www.iteea.org/news/tee
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
The goal of this project is to gain a better understanding of the importance of structural integrity and how structures behave under motion. This report intends to investigate and analyze structural dynamics’ concepts with 3-D printed components in four unique challenges. Challenge 1 explores angular acceleration and rotational dynamics through a 3-D printed wheel. Challenge 2 focuses on reciprocating motion by designing and assembling a mechanism that is connected to a 3-D printed shake table. Challenge 3 involves creating structural columns which are assembled in a single-story structure. It also dives into concepts such as the natural frequency of a structure and how elements of design will influence it. Challenge 4 incorporates both Challenges 2 and 3 by shaking the single-story structure through the reciprocating motion mechanism. It also looks at important structural dynamics’ concepts such as transmissibility and resonance.The 3D-printing Dynamics Design (3D3) Competition intends to train School of Civil Engineering & Environmental Science (CEES) undergraduates at the University of Oklahoma in fundamental concepts related to vibrations, structural dynamics, and earthquake engineering through a semester-long, hands-on competition run in parallel with Introduction to Dynamics for Architectural and Civil Engineers (CEES 3263). Competition participants, or 3D3 Scholars, design, build, and test a bench-scale shake table using 3D-printed components. The designs of these shake tables are published here, along with all the STL files needed for teachers or students elsewhere to fabricate the tables. Also, the data collected during the challenges is published.more » « less
-
null (Ed.)The ability to manufacture biodegradable structures at small scales is integral to a variety of applications in biological, medical, and pharmaceutical fields. Recent developments in additive manufacturing (or "three-dimensional (3D) printing") allow for biodegradable materials to be printed with high resolution; however, there is typically a limit with respect to a resolvable feature size (e.g., layer height) that dictates the minimum increments for tuning distinct degradation-mediated functionalities via print geometry. Here we investigate the potential to 3D print designs that afford additional degrees of control during intermediate stages between the complete biodegradation of microstructures that differ by a single layer height. Preliminary fabrication results revealed effective printing of tubular 3D biodegradable gelatin methacryloyl (GelMA) structures with outer diameters of 100 μm and wall thicknesses of 35 μm using two-photon direct laser writing (DLW)-based additive manufacturing. Simulation results for varying designs suggest that both the total degradation time as well as the diffusion dynamics through a microstructure during the final stage of biodegradation can be modulated via geometric means. Thus, the concepts presented in this work could open new avenues in areas including drug delivery and biomaterials.more » « less
-
This report will explore concepts regarding structural dynamics through the utilization of a 3-D printed structure. The report has been broken into 4 challenges, each with its own concept being investigated. Within Challenge 1, a wheel was designed and printed to generate the lowest possible angular acceleration while gathering examining the theory behind rotational motion. Challenge 2 explored cyclical motion as this is where the shake table was designed and constructed. This challenge allowed for an understanding of how ground motion can be generated under a structure. Challenge 3 consisted of free vibration tests through the design of columns with a targeted natural frequency. Challenge 4 compounded off of Challenge 2 and Challenge 3 when the structure was subjected to forced, cyclical motion, from the shake table in order to explore concepts such as displacement and transmissibility generated from a structure subjected to forced vibration.The 3D-printing Dynamics Design (3D3) Competition intends to train School of Civil Engineering & Environmental Science (CEES) undergraduates at the University of Oklahoma in fundamental concepts related to vibrations, structural dynamics, and earthquake engineering through a semester-long, hands-on competition run in parallel with Introduction to Dynamics for Architectural and Civil Engineers (CEES 3263). Competition participants, or 3D3 Scholars, design, build, and test a bench-scale shake table using 3D-printed components. The designs of these shake tables are published here, along with all the STL files needed for teachers or students elsewhere to fabricate the tables. Also, the data collected during the challenges is published.more » « less
-
The report involves the application and testing of dynamics concepts through the use of 3D-printed components. It includes various challenges promoting innovation and critical thinking. Challenge 1 focused on exploring angular motion through the design of a 3D-printed wheel. In Challenge 2, a shake table was developed by creating a reciprocating mechanism that converted rotational-to-linear motion. The kinematic relations of the 3D model were derived from the geometry of the mechanism to meet a targeted acceleration. Challenge 3 applied structural dynamics concepts by designing columns of a structure to meet a natural frequency. Challenge 4 built upon previous challenges to test a structure and shake table under forced vibrations. The results from the experiment were used to analyze the dynamic response of a structural system. The challenges integrated 3D design and mathematical modeling to understand the importance of dynamic behaviors in structural engineering.The 3D-printing Dynamics Design (3D3) Competition intends to train School of Civil Engineering & Environmental Science (CEES) undergraduates at the University of Oklahoma in fundamental concepts related to vibrations, structural dynamics, and earthquake engineering through a semester-long, hands-on competition run in parallel with Introduction to Dynamics for Architectural and Civil Engineers (CEES 3263). Competition participants, or 3D3 Scholars, design, build, and test a bench-scale shake table using 3D-printed components. The designs of these shake tables are published here, along with all the STL files needed for teachers or students elsewhere to fabricate the tables. Also, the data collected during the challenges is published.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- The DOI is not currently available.
