Plastic optical fiber was chosen for information delivery media in smart textile. Cladding layer was peeled off by chemical and mechanical methods to find optimal peeling conditions. Both radial side illumination and longitudinal end-tip illumination were measured for visible light of 627 µm wavelength. A half-cone-shaped jig was manufactured using 3D printing to give various curvature conditions to fibers. Also POFs were embedded in plain weave textile structure to measure the light dissipation effect. The waveguide phenomenon was modeled using discrete ray tracing technique and ray-to-interface collision detection algorithm. Results from the proposed modeling technique showed linear relationship with those from experiment.

An advanced theoretical method to simulate the light delivery in plastic optical fiber is presented. e final objective is to use "light" as a new media for information delivery in wearable computers. A large-time-step-based ray-tracing algorithm, which was improved from our previous research, was used to simulate the light vector movement in a complex weave structure efficiently. NURBS and free-form-deformation-based modeling was used to mimic the arbitrary weave structure. Experimentally, optical fibers were modified to control the direction of light emission. Particularly, half side of a cladding layer in the radial direction was selectively removed to enhance one-sided fabric light scattering. e cladding-removed plastic optical fiber was adopted in a textile weave structure, and its light scattering was measured quantitatively by varying the removal length, fiber curvature, and fabric weave patterns. To show the validity of the proposed simulation technique, twill structures with varying number of cross repeat numbers were used as a testbed. e unit number 2 was found to be the optimal structure for light emission, when a single POF was embedded in the textile. e proposed model showed the similar result with the actual light intensity measurement, with computation time not much than one second.

Plastic optical fibers (POF) have several advantages over the conventional glass optical fibers (GOF), such as flexibility and transfer of visible lights. For information delivery, various IT devices can be interconnected into or onto the fabric. For aesthetic value, fabric can be active light emission device using optical fiber. In this work, we propose a light emission fabric which contains optical fiber structure with the external clad layer removed using mechanical or chemical method. POF was embedded into plain weave structure and the light scattering phenomenon was measured quantitatively by specially designed 3D printed jig using google SketchUp software. Various light frequency including 405nm, 455nm, 530nm and 627 nm tested because visible and UV lights were of our concern. Thermal and mechanical force were used for the clad removal respectively and the removal status was measured using microscope. Light scattering was stronger in clad-removed fibers, especially 5 times in 455 nm.

Purpose The purpose of this paper is to provide an efficient tool for simulating electrospinning process in virtual 3D space and optimizing experimental parameters. The fiber orientation from virtual or real electrospinning process can be easily measured using the image analysis technique. Using the semi-implicit Euler integration, the time integration can be more fast and stable, which enabled optimization of the electrospinning process. Also boundary conditions can be easily adopted during conjugate gradient matrix solving step. Design/methodology/approach To simulate the electrospinning process, the authors have adopted a particle-based modeling technique using the molecular dynamics theory, which is known to be suitable for modeling materials with nonlinear and nonhomogeneous behavior such as fibers or fabrics. Gravitational, tensional, and electrostatical forces and their Jacobians were carefully defined and chosen to maintain the stability of the governing equation. Preconditioned conjugate gradient method was used to solve the matrix iteratively with boundary conditions. The 2-D metaball fitting technique, which was applied in the previous research (Sul et al., 2009) on experimental nanofiber scanning electron microscopy images, was utilized with virtual nanofiber images. A staircase function and a new shading language were proposed to automatically calculate the orientation and radius distribution of the graphically simulated electrospun fiber structures. The automatic measurement procedure was verified via graphically designed virtual replica images. Also the orientation tendency acquired from the simulation was compared with that of experimental data. Findings Simulation result of fiber orientation showed linear relationship with the collecting drum speed. Use of particle-based method generated a simple system to simulate electrospinning process. Originality/value The semi-implicit Euler integration was applied to the electrospinning process and the final linear system was numerically stable to solve.

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