Two-Way 4D Printing: A Review on the Reversibility of 3D-Printed Shape Memory Materials

Abstract In recent years, more and more attentions have been attracted on integrating three-dimensional (3D) printing with fields (such as magnetic field) or innovating new methods to reap the full potential of 3D printing in manufacturing high-quality parts and processing nano-scaled composites. Among all of newly innovated methods, four-dimensional (4D) printing has been proved to be an effective way of creating dynamic components from simple structures. Common feeding materials in 4D printing include shape memory hydrogels, shape memory polymers, and shape memory alloys. However, few attempts have been made on 4D printing of ceramic materials to shape ceramics into intricate structures, owing to ceramics’ inherent brittleness nature. Facing this problem, this investigation aims at filling the gap between 4D printing and fabrication of complex ceramic structures. Inspired by swelling-and-shrinking-induced self-folding, a 4D printing method is innovated to add an additional shape change of ceramic structures by controlling ZrO2 contents and patterns. Experimental results evidenced that by deliberately controlling ZrO2 contents and patterns, 3D-printed ceramic parts would undergo bending and twisting during the sintering process. To demonstrate the capabilities of this method, more complex structures (such as a flower-like structure) were fabricated. In addition, functional parts with magnetic behaviors were 4D-printed by incorporating iron into the PDMS-ZrO2 ink.

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A Review on Development of Soft Gripper Using 4D Printing

INTERNATIONAL JOURNAL OF ADVANCED PRODUCTION AND INDUSTRIAL ENGINEERING ◽

10.35121/ijapie202007348 ◽

2020 ◽

Vol 5 (3) ◽

pp. 49-55

Author(s):

Ashutosh Singh ◽

◽

Ravi Butola ◽

Jitendra Bhaskar ◽

Keyword(s):

3D Printing ◽

Shape Memory ◽

Advanced Materials ◽

Soft Robotics ◽

4D Printing ◽

Silicone Elastomers ◽

System Architectures ◽

Shape Memory Materials ◽

End Effectors ◽

Future Work

Improvements in soft robotics, materials, and flexible gripper technology made it possible for the soft grippers to advance rapidly. A brief analysis of soft robotic grippers featuring various material collections, physical rules, and system architectures is provided here. Soft gripping is divided into three technologies, enabling gripping with: a) actuation, b) material used, and c) Use of 3D printing in fabricating grippers. An informative analysis is provided of every form. Similar to stiff grippers, flexible and elastic end-effectors may also grab or control a broader variety of objects. The inherent versatility of the materials is increasingly being used to study advanced materials and soft structures, particularly silicone elastomers, shape-memory materials, active polymers, and gels, in the development of compact, simple, and more versatile grippers. For future work, enhanced structures, techniques, and senses play a prominent part.

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Frontally polymerizable shape memory polymer for 3D printing of free-standing structures

Smart Materials and Structures ◽

10.1088/1361-665x/ac41ea ◽

2021 ◽

Author(s):

Yongsan An ◽

Joon Hyeok Jang ◽

Ji Ho Youk ◽

Woong-Ryeol Yu

Keyword(s):

Shape Memory ◽

Memory Performance ◽

Shape Memory Polymer ◽

Three Dimensional ◽

Frontal Polymerization ◽

4D Printing ◽

Free Standing ◽

Time Shape ◽

Standing Structure ◽

3D Printed

Abstract Four-dimensional (4D) printing is used to describe three-dimensional (3D)-printed objects with properties that change over time. Shape memory polymers (SMPs) are representative materials for 4D printing technologies. The ability to print geometrically complex, free-standing forms with SMPs is crucial for successful 4D printing. In this study, an SMP capable of frontal polymerization featuring exothermic self-propagation was synthesized by adding cyclooctene to a poly(dicyclopentadiene) network, resulting in switching segments. The rheological properties of this SMP were controlled by adjusting incubation time. A nozzle system was designed such that the SMP could be printed with simultaneous polymerization to yield a free-standing structure. The printing speed was set to 3 cm/min according to the frontal polymerization speed. A free-standing, hexagonal spiral was successfully printed and printed spiral structure showed excellent shape memory performance with a fixity ratio of about 98% and a recovery ratio of 100%, thereby demonstrating the 3D printability and shape memory performance of frontally polymerizable SMPs.

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4D Printing of Shape Memory Materials for Textiles: Mechanism, Mathematical Modeling, and Challenges

Advanced Functional Materials ◽

10.1002/adfm.202100257 ◽

2021 ◽

pp. 2100257

Author(s):

Manik Chandra Biswas ◽

Samit Chakraborty ◽

Abhishek Bhattacharjee ◽

Zaheeruddin Mohammed

Keyword(s):

Mathematical Modeling ◽

Shape Memory ◽

4D Printing ◽

Shape Memory Materials

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Shape memory materials and 4D printing in pharmaceutics

Advanced Drug Delivery Reviews ◽

10.1016/j.addr.2021.03.013 ◽

2021 ◽

Vol 173 ◽

pp. 216-237

Author(s):

Alice Melocchi ◽

Marco Uboldi ◽

Matteo Cerea ◽

Anastasia Foppoli ◽

Alessandra Maroni ◽

...

Keyword(s):

Shape Memory ◽

4D Printing ◽

Shape Memory Materials

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Editorial: Shape Memory Materials for Medical Devices

The Open Medical Devices Journal ◽

10.2174/1875181401002020001 ◽

2010 ◽

Vol 2 (2) ◽

pp. 1-1

Author(s):

WM Huang ◽

CL Song ◽

YQ Fu

Keyword(s):

Shape Memory ◽

Medical Devices ◽

Shape Memory Materials

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Pressure Orientation-Dependent Recovery of 3D-Printed PLA Objects with Varying Infill Degree

Polymers ◽

10.3390/polym13081275 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1275 ◽

Cited By ~ 1

Author(s):

Guido Ehrmann ◽

Andrea Ehrmann

Keyword(s):

Shape Memory ◽

Fused Deposition Modeling ◽

Static Load ◽

Shape Memory Polymer ◽

Applied Pressure ◽

Poly Lactic Acid ◽

Fused Deposition ◽

Deposition Modeling ◽

Load Tests ◽

3D Printed

Poly(lactic acid) is not only one of the most often used materials for 3D printing via fused deposition modeling (FDM), but also a shape-memory polymer. This means that objects printed from PLA can, to a certain extent, be deformed and regenerate their original shape automatically when they are heated to a moderate temperature of about 60–100 °C. It is important to note that pure PLA cannot restore broken bonds, so that it is necessary to find structures which can take up large forces by deformation without full breaks. Here we report on the continuation of previous tests on 3D-printed cubes with different infill patterns and degrees, now investigating the influence of the orientation of the applied pressure on the recovery properties. We find that for the applied gyroid pattern, indentation on the front parallel to the layers gives the worst recovery due to nearly full layer separation, while indentation on the front perpendicular to the layers or diagonal gives significantly better results. Pressing from the top, either diagonal or parallel to an edge, interestingly leads to a different residual strain than pressing from front, with indentation on top always firstly leading to an expansion towards the indenter after the first few quasi-static load tests. To quantitatively evaluate these results, new measures are suggested which could be adopted by other groups working on shape-memory polymers.

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Structural multi-colour invisible inks with submicron 4D printing of shape memory polymers

Nature Communications ◽

10.1038/s41467-020-20300-2 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Wang Zhang ◽

Hao Wang ◽

Hongtao Wang ◽

John You En Chan ◽

Hailong Liu ◽

...

Keyword(s):

Shape Memory ◽

Information Hiding ◽

Shape Memory Polymer ◽

Shape Memory Polymers ◽

Photonic Devices ◽

Temperature Sensitive ◽

4D Printing ◽

Two Photon ◽

Shape Memory Effects ◽

Nanoscale Structure

AbstractFour-dimensional (4D) printing of shape memory polymer (SMP) imparts time responsive properties to 3D structures. Here, we explore 4D printing of a SMP in the submicron length scale, extending its applications to nanophononics. We report a new SMP photoresist based on Vero Clear achieving print features at a resolution of ~300 nm half pitch using two-photon polymerization lithography (TPL). Prints consisting of grids with size-tunable multi-colours enabled the study of shape memory effects to achieve large visual shifts through nanoscale structure deformation. As the nanostructures are flattened, the colours and printed information become invisible. Remarkably, the shape memory effect recovers the original surface morphology of the nanostructures along with its structural colour within seconds of heating above its glass transition temperature. The high-resolution printing and excellent reversibility in both microtopography and optical properties promises a platform for temperature-sensitive labels, information hiding for anti-counterfeiting, and tunable photonic devices.

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