Shape-reversible 4D printing aided by shape memory alloys

Akbari，Saeed1; Sakhaei，Amir Hosein2; Panjwani，Sahil3; Kowsari，Kavin3; Ge，Qi3,4

2022

4D printing Finite element analysis Shape memory alloy Shape memory polymer

English

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.

10.1016/B978-0-323-95430-3.00014-2

Smart Materials in Additive Manufacturing, volume 2: 4D Printing Mechanics, Modeling, and Advanced Engineering Applications

387-406

Others

2-s2.0-85137545257

Scopus

1.RISE Research Institutes of Sweden,Mölndal,Sweden
2.School of Engineering and Digital Arts,University of Kent,Canterbury,United Kingdom
3.Digital Manufacturing and Design Center,Singapore University of Technology and Design,Singapore,Singapore
4.Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen,China

Akbari，Saeed,Sakhaei，Amir Hosein,Panjwani，Sahil,et al. Shape-reversible 4D printing aided by shape memory alloys. 2022-01-01.