4D Printing of Single-Network Shape Memory Polyurethanes with Two-Way Actuation Properties

Abstract

Two-way shape memory polymers (SMPs) have received much attention due to their ability to enable stimuli-responsive reversible structures without requiring repeated human intervention, which may be useful for application in many fields where multiple actuation cycles are desired. However, many layered or composite SMP systems are not integrated structures and suffer from several disadvantages, such as poor interlayer adhesion with limited actuation repeatability. In addition, twoway SMPs are limited by their manufacturing method to producing userdefined, complex, high-precision devices and parts. In this work, we developed a 3D-printable resin comprising two polyurethane-based oligomers with distinctly different transition temperatures�polypentadecalactone diacrylate (PPDLDA) and polycaprolactone diacrylate (PCLDA)�together with other monomers to fabricate single-network two-way shape memory smart materials by digital light projection 3D printing. The chemical, mechanical, and thermal properties of printed products can be easily tuned by facile manipulation of monomer and oligomer compositions. The PCLDA and PPDLDA switching segments were found to exhibit high mean shape fixity ratios (R f ) of >97% and high shape recovery ratios (R r ) of >89%. The strategy for achieving 3D-printable single-network two-way SMPs presented herein holds promise for applications in soft robotics, medicine, and so forth.

Sustainable Robots 4D Printing

“…[228] Another widely used sustainable technique for the fabrication of BSSA is VPP. TPETA, [83] GelMA, [84,85] AAm, [117] PEGDA, [88][89][90][91]107,113,117,130,140,147] PCLDMA, [87,103] photocurable PLA, [110] PCLDA, [86,129] gelatin, [99] photocurable chitosan-based polymer, [34] PETA, [107] photocurable alginate-based polymer, [100] PEGMA, [101] PGMEA, [108] PEGgel, [92] and PEGDMA [149] are among biodegradable materials used to make appropriate photocurable polymer for VPP technique. Biocompatibility and biodegradability can be tailored by using different base monomers, and the modulus of elasticity and strength of the final product can be modified by altering the degree of crosslinking.…”

“…Reproduced with permission. [ 129 ] Copyright 2022, American Chemical Society. c) DLP 3D‐printed pneumatic soft actuator with two fingers capturing a soft rubber pipette bulb.…”

“…This is because they are highly crystalline, have low toxicity, have mechanical properties that can be changed easily, and break down quickly. [ 259,260 ] Jiang et al [ 129 ] discussed how the use of smart materials in 3D printing allows for the creation of structures with programmable and adaptable shapes, properties, or functionalities. They fabricated a 3D‐printable resin that can produce single‐network two‐way shape memory smart materials.…”

“…[238] Unfortunately, because of their restricted range of mechanical and chemical characteristics, these polymers are only suitable for particular kinds of tissue replacement scaffolds. TPETA, [83] GelMA, [84,85] Acrylamide (AAm), [117] PEGDA, [88][89][90][91]107,113,117,130,140,147] photocrosslinkable polycaprolactone dimethyl acrylate (PCLDMA), [87,103] photocurable PLA, [110] photocurable polycaprolactone diacrylate (PCLDA), [86,129] gelatin, [99] photocurable chitosan-based polymer, [34] pentaerythritol tetraacrylate (PETA), [107] photocurable alginate-based polymer, [100] poly(ethylene glycol) methyl ether methacrylate (PEGMA), [101] propylene glycol methyl ether acetate (PGMEA), [108] PEGgel, [92] and polyethylene glycol dimethacrylate (PEGDMA) [149] are among biodegradable materials used to make appropriate photocurable polymer for VPP technique. In the following sections, several facets of each VPP approach have been addressed in more detail.…”

“…b) DLP 4D Printing of single-network SMP with two-way actuation properties. Reproduced with permission [129]. Copyright 2022, American Chemical Society.…”