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Shape-reversible 4D printing aided by shape memory alloys

Akbari, Saeed and Sakhaei, Amir Hosein and Panjwani, Sahil and Kowsari, Kavin and Ge, Qi (2022) Shape-reversible 4D printing aided by shape memory alloys. In: Smart Materials in Additive Manufacturing. Volume 2: 4D Printing Mechanics, Modeling, and Advanced Engineering Applications. Elsevier. ISBN 978-0-323-95430-3. (doi:10.1016/B978-0-323-95430-3.00014-2) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided) (KAR id:96073)

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Four-dimensional (4D) printed structures fabricated from shape memory polymers (SMPs) are typically one-way actuators, that is, for each actuation cycle, they must be programmed to deform from the original (as-printed) shape to a secondary (programmed) shape. This is done by applying a combination of thermal and mechanical loads. Then, they restore the initial shape during the actuation process by applying a thermal load. Here, we generalize this concept to fabricate two-way actuators by embedding shape memory alloy (SMA) wires into the printed SMP structures. To explain this in greater detail, we describe the printing process of a two-way bending actuator whose bilayer hinges consist of stiff SMPs as well as elastomers with low modulus. Joule heating was employed to modulate the hinges bending stiffness. To this end, electrical current was applied to the resistive wires inserted into the hinges SMP layer to control their temperature. On the other hand, thermomechanical programming of the SMA wires, which were integrated into the actuator, provided the bending actuation force. The fabricated actuator was able to bend, maintain the deformed shape, and recover the as-fabricated shape in a fully automated manner. Further potentials of this design methodology were assessed using a nonlinear finite element model. The model incorporated user-defined subroutines to incorporate complex material behaviors of SMAs and SMPs.

Item Type: Book section
DOI/Identification number: 10.1016/B978-0-323-95430-3.00014-2
Uncontrolled keywords: 4D printingShape memory alloyShape memory polymerFinite element analysis
Subjects: T Technology > TA Engineering (General). Civil engineering (General)
T Technology > TJ Mechanical engineering and machinery
Divisions: Divisions > Division of Computing, Engineering and Mathematical Sciences > School of Engineering and Digital Arts
Depositing User: Amirhosein Sakhaei
Date Deposited: 05 Aug 2022 10:21 UTC
Last Modified: 12 Aug 2022 11:00 UTC
Resource URI: (The current URI for this page, for reference purposes)

University of Kent Author Information

Sakhaei, Amir Hosein.

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