4D printing of shape memory polylactic acid (PLA)

doi:10.1016/j.polymer.2021.124080

Polymer

Volume 230, 16 September 2021, 124080

https://doi.org/10.1016/j.polymer.2021.124080 Get rights and content

Under a Creative Commons license

open access

Highlights

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The current state of the art on 4D printing of polylactic acid polymer is achieved.
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Properties and shape memory behavior of polylactic acid polymer is thoroughly reviewed and discussed.
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Various types of shape-shifting behaviors and mechanisms in the 4D printed structures are presented.
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The impact of process parameters on the functionality of the fabricated products is discussed.

Abstract

Additive manufacturing has attracted much attention in the last decade as a principal growing sector of complex manufacturing. Precise layer-by-layer patterning of materials gives rise to novel designs and fabrication strategies that were previously not possible to realize with conventional techniques. Using suitable materials and organized variation in the printing settings, parts with time-dependent shapes that can be tuned through environmental stimuli can be realized. Given that these parts can either change their shape over time to a pre-programmed three-dimensional shape or revert to an initial design, this process has become referred to as four-dimensional (4D) printing. In this regard, the commonly-used polylactic acid (PLA) polymer has been recognized as a compelling material candidate for 4D printing as it is a biobased polymer with great shape memory behavior that can be employed in the design and manufacturing of a broad range of smart products. In this review, we investigate the material properties and shape memory behavior of PLA polymer in the first section. Then, we discuss the potential of PLA for 4D printing, including the principles underlying the strategy for PLA-based printing of self-folding structures. The resulting materials exhibit response to environmental stimulus as well as temperature, magnetic field, or light. We additionally discuss the impact of geometrical design and printing conditions on the functionality of the final printed products.

Graphical abstract

Keywords

Additive manufacturing

4D printing

PLA

Shape memory polymer

Programmable structures

Cited by (0)

Mehrshad Mehrpouya earned his Ph.D. degree through a fellowship program from Sapienza University of Rome (Italy) in 2017. He is currently an Assistant Professor in the Department of Design, Production, and Management (DPM) at the University of Twente (UT). His research interests are directed toward Advanced Manufacturing, 3D/4D Printing, Functional Materials, and modeling.

Henri Vahabi received his Ph.D. in Materials Science from the University of Montpellier, France, in 2011. Since then, he joined the University of Lorraine, France as an Associate Professor. His main research interests include flame retardancy of polymeric materials and nanocomposites. He has authored over 100 peer-reviewed scientific articles/book chapters.

Shahram Janbaz received his Ph.D. from TU Delft, the Netherlands. He is currently a Post-Doctoral researcher in the institute of physics at the University of Amsterdam. His research interests are mechanical and smart metamaterials.

Arash Darafsheh is an Associate Professor of Radiation Oncology, a certidied medical physicist by the American Board of Radiology (ABR), and the PI of the Optical Imaging and Dosimetry Lab at the Washington University School of Medicine. He earned a Ph.D. in optical science and engineering in 2013 from the University of North Carolina at Charlotte. His current research interets include optical methods in medical physics, novel radiation dosimeters, ultra-high dose rate radiation therapy, and super-resolution microscopy.

Thomas Mazur is an Assistant Professor of Radiation Oncology at the Washington University School of Medicine. He joined the faculty in 2016. He received his Ph.D. in physics at The University of Texas at Austin in 2014. He is interested in the application and development of advanced technologies for improving radiation therapy.

Seeram Ramakrishna is the Director of the Center for Nanofibres and Nanotechnology at the National University of Singapore (NUS), which is ranked among the top 20 universities in the world. He is regarded as the modern father of electrospinning. He is an elected Fellow of UK Royal Academy of Engineering (FREng); Singapore Academy of Engineering; Indian National Academy of Engineering; and ASEAN Academy of Engineering & Technology. He is an elected Fellow of the International Union of Societies of Biomaterials Science and Engineering (FBSE); Institution of Engineers Singapore; ISTE, India; Institution of Mechanical Engineers and Institute of Materials, Minerals & Mining, UK; and American Association of the Advancement of Science; ASM International; American Society for Mechanical Engineers; American Institute for Medical & Biological Engineering, USA. He is an editor of Elsevier journal Current Opinion in Biomedical Engineering.