Page 80 - IJB-6-2

3D printed fabric silicone composite
A B C

D E G H

F

I

Figure 5. Investigation of adhesion of three-dimensional (3D) printed silicone on fabric: (A) Viscosity
curve of the silicone print mixtures with different thickener contents; (B) and (C) demonstration of the
problem of extremely low viscosity of print mixture for first layer printing, (D) schematic of ASTM
D5169; (E) image of 3D printing process of ASTM D5169; (F) image of a ASTM D5169 sample;
(G) plotted shearing forces versus extension; (H) maximum shearing force comparison; (I) cross-sectional
observation of (i) 0.2 wt%_Thickener_0.4 mm sample, (ii) 0.2 wt%_Thickener sample, and (iii) 2 wt%_
Thickener sample; Scale bar: 200 μm.

as shown in Figure 5Iiii. Therefore, its shear adhesion of the printed material and fabric, the
strength is mainly contributed by the adhesion size of the print model should be considered. As
and friction of the silicone and fabric and result the fabric has high flexibility, the distance between
in much lower shearing strength than the other the build platform and fabric can be reduced due
samples. to gravity, especially in the middle of the elevated
The proposed printing approach here shows a area if a large print model is required. As a result,
dramatic improvement of adhesion (600% in shear the adhesion between the fabric and silicone can
strength) between the fabric and silicone which be reduced. Furthermore, the shape of the model
demonstrates its potential for customizing any for printing can be affected due to the caving-in of
type of application, such as wearable electronics, the fabric.
soft robotics, engineered foot insoles, and orthotic 3.2.2 Tensile properties
bracewear.
Although the use of the proposed multi- The durability of a material is a key element of
material approach on elevated fabric improves the pressure therapy because undependable materials

76 International Journal of Bioprinting (2020)–Volume 6, Issue 2