3D Printed Shape Memory Polymers Produced via Direct Pellet Extrusion

Abstract

Shape memory polymers (SMPs) are materials capable of changing their structural configuration from a fixed shape to a temporary shape, and vice versa when subjected to a thermal stimulus. The present work has investigated the 3D printing process of a shape memory polymer (SMP)-based polyurethane using a material extrusion technology. Here, SMP pellets were fed into a printing unit, and actuating coupons were manufactured. In contrast to the conventional film-casting manufacturing processes of SMPs, the use of 3D printing allows the production of complex parts for smart electronics and morphing structures. In the present work, the memory performance of the actuating structure was investigated, and their fundamental recovery and mechanical properties were characterized. The preliminary results show that the assembled structures were able to recover their original conformation following a thermal input. The printed parts were also stamped with a QR code on the surface to include an unclonable pattern for addressing counterfeit features. The stamped coupons were subjected to a deformation-recovery shape process, and it was observed that the QR code was recognized after the parts returned to their original shape. The combination of shape memory effect with authentication features allows for a new dimension of counterfeit thwarting. The 3D-printed SMP parts in this work were also combined with shape memory alloys to create a smart actuator to act as a two-way switch to control data collection of a microcontroller.

Shape Memory Polymer-Based Endovascular Devices: Design Criteria and Future Perspective

“…By means of obtaining the aneurysm geometry through patient imaging data (e.g., magnetic resonance or computed-tomography imaging), a patient-specific aneurysm geometry could be printed using FDM to obtain a porous endovascular device. FDM has been utilized for the printing of materials with shape memory capacities, including the use of polylactic acid (PLA) [70][71][72], polyurethane [73][74][75], polycyclooctene (PCO) [76], polyvinyl alcohol (PVA) [77], among others [78].…”

“…These designs can also be a promising approach for the design of personalized endovascular devices tailored to patient-specific ICA geometries. Other examples for 3D-printed SMPs include stents [72] and wearable devices [74].…”

4D printing of soft orthoses for tremor suppression

“…Hand orthoses made of SMMs are efficient in tremor suppression. Shape memory alloys (SMAs) have been utilized in a flexible wearable actuator for hand tremor suppression [113,114]. Shape memory polymers (SMPs) have significantly contributed to the 4D printing of soft wearable actuators [115], yielding a high recovery rate of 96% [116].…”

A Brief Review on Additive Manufacturing of Polymeric Composites and Nanocomposites

“…As a result, the drive to improve treatment options to address these disadvantages has intensified in recent years. Other research [ 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 ] looked at the effect of the defects on the mechanical efficiency of FRC and subsequently discussed treatment options for removing or minimizing them to improve the functional properties of the fabricated parts. Since FRCs are made up of a polymeric matrix and a short or continuous fiber reinforcement, the analysis will go through the effects of AM parameters such as infill pattern, layer thickness, raster angle, and fiber orientation on both thermoplastic polymers and FRCs printed using FDM technology.…”