Woven active-matrix display

Abstract

In this paper, we present a woven textile display enabled by replacing standard textile threads with flexible stripes. Each stripe contains amorphous indium-gallium-zinc-oxide thin-film transistors (TFTs) that actuate light-emitting diodes (LEDs) on the same stripe. Weaving exposes thin-film layers on stripes to bending radii smaller than 200 μm (corresponding to strains higher than 10%). Therefore, we adapted our TFT fabrication process by omitting the usual blanket brittle silicon-nitride (SiN x) layer. TFTs fabricated without this layer have an equivalent electrical performance to devices fabricated using a SiN x layer. Furthermore, TFTs are locally protected from excessive bending by covering them with 1.6 mm × 0.8 mm surface mount device LEDs. To demonstrate the feasibility of weaving TFTs on flexible stripes into textiles, we fabricated stripes consisting of three TFTs connected to three LEDs. Three of these stripes were subsequently integrated into a textile using a commercial weaving machine to create a 3 × 3 LED matrix. The matrix was completed using conductive textile threads that are inserted perpendicular to the woven stripes to connect contact pads on adjacent stripes. The results show that TFTs can be woven into textiles without performance loss. © 2011 IEEE.