3D Printing of Carbon Nanotube (CNT)/Thermoplastic Polyurethane (TPU) Functional Composites and Preparation of Highly Sensitive, Wide‐range Detectable, and Flexible Capacitive Sensor Dielectric Layers via Fused Deposition Modeling (FDM)

Abstract

3D printing platform to directly form the desired 3D part. [4][5][6][7] Compared with other 3D printing methods, FDM has the advantages of low cost, simple principle, and high reliability. However, the development of the FDM process is limited by the small variety of available filaments, the poor mechanical properties, and the lack of functionality of the printed parts. [8][9][10] Researchers have mostly focused on the study of FDM process parameters to solve the problems such as the poor mechanical properties of the printed parts. [11,12] Korkut et al. [13] studied the influence of FDM printing process parameters, such as line width, layer thickness, and filler orientation, on the tensile strength and quality of samples. Wang et al. [14] studied the effects of printing parameters such as the FDM nozzle temperature, platform temperature, printing speed and layer thickness on mechanical properties such as tensile strength, flexural strength, and impact strength. Cerda-Avila et al. [15] studied the effects of the filler orientation, layer thickness, and filler morphology on Young's modulus and the ultimate tensile stress of materials. Garzon-Hernandez et al. [16] studied the effects of cavity density and filament orientation on the mechanical properties of samples. Wang et al. [17] studied the influence of printing angle, nozzle temperature, and filling rate materials on mechanical properties. Vicente et al. [18] studied the influence of interlayer cooling time, nozzle diameter, layer thickness, and other parameters on the mechanical properties of FDM processing parts.

Study on CNT/TPU Cubic under the 3D Printing Conditions of Infill Patterns and Density

“…As for the research on manufacturing sensors by synthesizing TPU and carbon nanomaterials, there have been studies on manufacturing sensors with CNT/TPU [22][23][24] , GR/TPU [25][26][27][28] , and CB/TPU [29,30] . In particular, various studies applying carbon/TPU to the 3D printing process are also being conducted.…”

Study on CNT/TPU cube under the 3D printing conditions of infill patterns and density

“…Thermoplastic polyurethane (TPU) is used to impart excellent stretchability and flexibility 25 – 27 . As for the research on manufacturing sensors by synthesizing TPU and carbon nanomaterials, there have been studies on manufacturing sensors with CNT/TPU 28 – 30 , GR/TPU 31 – 34 , and CB/TPU 35 , 36 . In particular, various studies applying carbon/TPU to the 3D printing process are also being conducted.…”

Three-dimensional printed re-entrant strain sensor using various carbon types/thermoplastic polyurethane filaments

“…Therefore, it was shown that 3D printing can improve the performance of carbon/TPU. [20][21][22][23] Accordingly, the development of sensors using GR-TPU, [24][25][26][27] CF-TPU, 28 CB-TPU, 15,29 and CNT-TPU [30][31][32][33][34] has been recently investigated. Li et al 26 manufactured a filament by mixing and blending various GR contents (3 wt%) and TPU.…”