Introduction

Review on development and application of 4D-printing technology in smart textiles

“…Technical schematic diagram of 4D printing smart textiles: 25 (a) fused deposition modeling, (b) direct ink writing, (c) stereo lithography appearance, (d) digital light processing, and (e) PolyJet.…”

“…After printing a single layer, the construction platform is lowered by one layer before a new layer of cross-sectional extruded curing is performed. This process is repeated layer-by-layer until the entire solid modeling is complete, 25 as shown in Figure 1(a). FDM utilizes hot-melt extrusion heads instead of precious metal components such as lasers, resulting in lower equipment and maintenance costs.…”

“…The DLP printing system comprises a DLP projection system, a mechanical motion system, and a master control system with computation and control capabilities. 25 The master control system must slice the 3D model of the manufactured part into a series of 2D flat images, after which the DLP projection system is directed to project the images while the projected ultraviolet (UV) light triggers the local free radical photopolymerization, which transforms the liquid photopolymer into a solid 3D object, as shown in Figure 1(d). In the process of printing smart textiles using DLP technology, the relationship between the UV energy absorbed during UV irradiation and the curing thickness of the light-cured material is a crucial variable.…”

“…34 Screw extrusion is driven by the rotation of the screw to extrude semi-fluid material from the nozzle. 25 The advantage of the screw extrusion method is the stable state of the extruded filament of the nozzle, which can speed up the pace of extruding materials with a high viscosity. Pneumatic type material extrusion is controlled by a solenoid valve to pass gas into the barrel and extrude the paste material or molten material inside the barrel from the nozzle.…”

“…Pneumatic type material extrusion is controlled by a solenoid valve to pass gas into the barrel and extrude the paste material or molten material inside the barrel from the nozzle. 25 Compared to piston extrusion printheads and screw extrusion printheads, pneumatic extrusion printheads have a simpler structure, a faster printing speed, and the ability to utilize a greater variety of molding materials. DIW can utilize materials with a variety of compositions and properties, including functional polymer systems, conductive polymer systems, and multi-substance material systems.…”