4D Printing: Post-processing for the masses

This research investigates the challenges a user faces in the activation step in shape-changing products. First, previous research on the topic of 4DP is reviewed and important factors are described. Namely, activation temperature, print temperature, print speed, and layer height have a signifi cant impact on the shrinkage...

Utilizing manufacturing-induced stresses for obtaining non-monostable compliant mechanisms

A broad range of bistable, multi-stable and neutrally stable compliant mechanisms have been developed over the years. These non-monostable systems show great potential for deployment in e.g. the medical, the manufacturing and the precision industry. Often the presence of prestress is a requirement for obtaining non-monostability within the realm...

Shape-memory polymer metamaterials based on triply periodic minimal surfaces

Triply periodic minimal surfaces (TPMS) metamaterials and shape-memory polymer (SMP) smart materials are known for their beneficial attributes in novel scientific and industrial fields. Through TPMS designs, low weight accompanied by high surface area are achievable, which are known as crucial parameters in many fields, such as tissue...

4D-printed shape memory polymer: Modeling and fabrication

Additive manufacturing (AM), as one of the most powerful manufacturing methods, is fabricating a three-dimensional (3D) structure using computer-aided design (CAD) data by adding material layer by layer. In contrast to traditional manufacturing processes that start from raw block material and remove waste materials, the AM process can...

Designing 3d-Printed Deployable Structures With Shape Memory Polymers

The aim of this project was to get a better understanding of the shape memory behaviour of 3D-printed polymers, and the different parameters which affect this, with the ultimate goal to apply shape memory in product design. This project started with a literature study on shape memory polymers and 3D-printing. The material properties, different...

Topology Optimization for 4D-Printed Structures

In recent developments in the field of multi-material additive manufacturing, differences in material properties are exploited to create printed shape memory structures, which are referred to as 4D-printed structures. New printing techniques allow for the introduction of prestresses in the specimen during manufacturing. This research focuses on...

Dual-action self-healing protective coatings with photothermal responsive corrosion inhibitor nanocontainers

This work introduces a novel nanocomposite coating with dual-action self-healing corrosion protection activated by the photothermal response of plasmonic titanium nitride nanoparticles (TiN NPs). TiN@mesoporous SiO₂ core–shell nanocontainers were developed as reservoirs for benzotriazole (BTA) corrosion inhibitors and incorporated...

Review of magnetic shape memory polymers and magnetic soft materials

Magnetic soft materials (MSMs) and magnetic shape memory polymers (MSMPs) have been some of the most intensely investigated newly developed material types in the last decade, thanks to the great and versatile potential of their innovative characteristic behaviors such as remote and nearly heatless shape transformation in the case of MSMs....

Nonlinear finite element modelling of thermo-visco-plastic styrene and polyurethane shape memory polymer foams

This paper presents nonlinear finite element (FE) models to predict time-and tempera-ture-dependent responses of shape memory polymer (SMP) foams in the large deformation regime. For the first time, an A SMP foam constitutive model is implemented in the ABAQUS FE package with the aid of a VUMAT subroutine to predict thermo-visco-plastic...

Numerical & Experimental Investigation of the Behavior of SMP Structural Joints

The main objective of the current study is the investigation of the behavior of structural joints consisting of Shape Memory Polymers. Taking into account the large environmental impact caused by the massive production of structural materials, the change of the current structural design philosophy is becoming essential. Conventional structural...

Triple-action self-healing protective coatings based on shape memory polymers containing dual-function microspheres

In this study, a new self-healing shape memory polymer (SMP) coating was prepared to protect the aluminum alloy 2024-T3 from corrosion by the incorporation of dual-function microspheres containing polycaprolactone and the corrosion inhibitor 8-hydroxyquinoline (8HQ). The self-healing properties of the coatings were investigated via scanning...

Programming of shape-shifting with 3D printers

Materials and devices with advanced functionalities often need to include functionalities such as surface features into complex 3D geometries. Precisely controlled bio-nanopatterns, printed electric components and sensors/actuators are all examples of such surface features. However, the vast majority of the refined technologies that are...

Long term stress relaxation behaviour of polyethylene terephthalate subjected to thermally activated restrained shrinkage

Research has been carried out with the aim of better understanding the relevant properties of materials to be used in a new self-healing cementitious composite material system. The system consists of shape memory polymer tendons embedded within a cementitious matrix, upon heat activation these tendons undergo a shrinkage process which closes any...

Self-healing coatings utilizing a shape memory effect

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Smart Materials For The Realization Of An Adaptive Building Component

This research focusses on the realization of adaptive architecture with the use of advanced material technology. Current material research has shown significant advances with the development of “smart” materials. Smart materials are “capable of automatically and inherently sensing or detecting changes in their environment and responding to those...