Fig. 2
From: Bifurcation-based embodied logic and autonomous actuation
Direct ink writing (DIW) of PDMS-glass fiber composites. a Schematic of extrusion of PDMS ink during DIW 3D printing, leading to alignment of glass fibers. b, c Rheological characterization of the PDMS-GF ink shows shear-thinning and yield-stress behavior, respectively. d An optical micrograph showing material printed using PDMS-GF ink (15 vol% glass fibers), with alignment of glass fibers along the print direction. e Stiffness of PDMS-GF composites (after curing of printed structures) as a function of the volume fraction of glass fibers and the fiber orientation, based on tensile testing of printed specimens (“Longitudinal” and “Transverse” indicate printing and fiber orientation that is parallel with or perpendicular to the loading direction, respectively), and fit using the Halpin–Tsai model64
