Steps Towards a Textile-Based Transistor: Development of the Gate and Insulating Layer

Abstract

Textiles are increasingly used in combination with electronics to create electronic textiles (so-called e-textiles). The evolution of electronic textiles began by attaching miniaAbstract During recent years, intensive research has been carried out in the area of electronic textiles. There is an emerging trend to create garments that host electronic components embedded in the textile substrate, as well as electronic textiles made from yarns or fibers already possessing electronic properties. The creation of passive devices, such as textile electrodes that measure body parameters, has proved successful. However, there is a great need for the development of textiles possessing additional active functions. Accordingly, we investigated the possibility of developing a textile substrate possessing integrated switching and amplification functions by depositing parts of an organic thin-film transistor on fibrous substrates of varying geometries and origins.This article relates the initial steps we employed to develop a textile-based thin-film transistor. It reports the development of a gate layer from the deposition of electroless copper, as well as the deposition of a polyimide dielectric layer using dip coating. Further, it discusses the layer's properties in terms of thickness and electrical characteristics.A copper layer of 350 nm thickness deposited on polyester tape and polyamide fibers displayed excellent electro-conductive properties. A smooth gate dielectric layer was achieved with a polyimide concentration of 15 w% and a withdrawal speed of 50 mm/min. As a result, optimum conditions for producing thin functional gate and dielectric layers were found. The transistor properties, the deposition of a semiconductive layer, and the production of drain and source electrodes remain the focus of future work.

Synthesis and characterization of copper, polyimide and TIPS-pentacene layers for the development of a solution processed fibrous transistor

“…In a previous study, 3 we already reported that a bottom-gate, top-contact configuration was preferred, as it allows an easier interconnection in textile applications.…”

Polyimide Dielectric Layer on Filaments for Organic Field Effect Transistors: Choice of Solvent, Solution Composition and Dip-Coating Speed

“…When coated at a lower concentration of 7.5w% as well as 10w% PI, all samples remain conductive over the entire range of withdrawal speed (threshold < 1010 Ωcm) [8]. Insulating layers were only obtained at a concentration of 12.5w%, when the dip-coating speed was relatively low, i.e.…”

“…The gate layer was thoroughly investigated by Schwarz et al (2010) [8]. The focus of this work is on the dielectric layer, which plays a significant role in the performance of microelectronic devices in general, for instance field effect transistors, LED or photovoltaic cells.…”

Progress in Flexible Electronic Textile for Heating Application: A Critical Review

“…Coatings on the conductive polymeric textile are carried out by sputtering, electroless plating, and deposition of vapour. In order to prepare conductive textiles, metal fibres are combined with traditional fibres during spinning [ 4 , 31 , 32 ]. During weaving and knitting, the processing of these yarns is difficult, consequential in fabrics with movable textile properties [ 16 , 33 ].…”