3D printing of shape memory polymers

Abstract

Shape memory polymers (SMPs) are polymers which ''remember'' their original shape and can return to it after deformation, if an external stimulus-often an increased temperatureis applied. Some SMPs can be 3D printed, typically by fused deposition modeling (FDM). The most well-known SMP is poly(lactic acid), which belongs to the most often used materials in FDM 3D printing. There are; however, many more SMPs which can be 3D printed to combine the possibilities to prepare new, sophisticated shapes with the opportunity to restore these shapes after undesirable or intentional deformation. This review gives an overview of several 3D printable SMPs, their mechanical characteristics and their possible applications.

Design, Construction and Tests of a Low-Cost Myoelectric Thumb

“…Printing was performed using an Ender V2 (Shenzhen Creality 3D Technology Co., Ltd., Shenzhen, China) with a nozzle diameter of 0.4 mm. As filament, polylactic acid (PLA) was chosen, which has advantages like good printability, being eco-friendly and degradable, and its shape memory properties allow for bending parts that cannot be printed easily in the desired shape [36,37]. The following parameters were used for printing: layer thickness 0.16 mm, 3 perimeters, fill density 20%, printing temperature 210 • C, printing bed temperature 50 • C, printing speed 50 mm/s, and the angle from which an overhang needs support structure was chosen as 51 • .…”

Volumetric additive manufacturing of shape memory polymers

“…Two common AM methods utilized to print SMP objects include melt material extrusion, which uses heat to thermally extrude SMP thermoplastics, and stereolithography, which uses light to cure photoresin layers to build the 3D structure. [12][13][14][15][16][17] As these methods use layer-by-layer assembly to build complex geometries, end-use objects often have anisotropic SMP responses and recovery depending on the part orientation during printing. 18 These layer effects can also impact the cyclic stability of SMP parts, as layers can act as mechanical defects leading to part failure.…”

Investigating inexpensive polymeric 3D printed materials under extreme thermal conditions

“…Applications can be found, e.g. in biotechnology, for orthoses and prostheses, as bumpers or for reinforcements of textile fabrics [5][6][7][8][9]. One of the most challenging applications is using 3D printed parts for space, e.g.…”