In today’s research, smart textiles is an established topic in both electronics and the textile fields. The concept of producing microelectronics directly on a textile substrate is not a mere idea anymore and several research institutes are working on its realisation. Microelectronics like organic field effect transistor (OFET) can be manufactured with a layered architecture. The production techniques used for this purpose can also be applied on textile substrates. Besides gate, active and contact layers, the isolating or dielectric layer is of high importance in the OFET architecture. Therefore, generating a high quality dielectric layer that is of low roughness and insulating at the same time is one of the fundamental requirements in building microelectronics on textile surfaces. To evaluate its potential, we have studied polyimide as a dielectric layer, dip-coated onto copper-coated polyester filaments. Accordingly, the copper-coated polyester filament was dip-coated from a polyimide solution with two different solvents, 1-methyl-2-pyrrolidone (NMP) and dimethylformaldehyde. A variety of dip-coating speeds, solution concentrations and solvent-solute combinations have been tested. Their effect on the quality of the layer was analysed through microscopy, leak current measurements and atomic force microscopy (AFM). Polyimide dip-coating with polyimide resin dissolved in NMP at a concentration of 15w% in combination with a dip-coating speed of 50 mm/min led to the best results in electrical insulation and roughness. By optimising the dielectric layer’s properties, the way is paved for applying the subsequent semi-conductive layer. In further research, we will be working with the organic semiconductor material TIPS-Pentacene
 Weiser M. THE COMPUTER FOR THE 21ST-CENTURY. Scientific American. 1991; 265: 94.
 Cooper KP and Tms. MATERIALS AND MANUFACTURING CHALLENGES IN HYBRID FLEXIBLE ELECTRONICS. 2010, p.27-40.
 Schwarz A, Cardoen J, Westbroek P, et al. Steps Towards a Textile-Based Transistor: Development of the Gate and Insulating Layer. Textile Research Journal. 2010; 80: 1738-46.
 Gao YL. Surface analytical studies of interfaces in organic semiconductor devices. Materials Science & Engineering R-Reports. 2010; 68: 39-87.
 Kwon JH, Seo JH, Shin SI, et al. A 6,13-bis(Triisopropy lsilylethynyl) pentacene thin-film transistor using a spun-on inorganic gate-dielectric. Ieee Transactions on Electron Devices. 2008; 55: 500-5.
 Knipp D, Street RA, Krusor B and Ho J. Pentacene thin film transistors and circuits: Influence of processing and device design. In: Jabbour GE, Carter SA, Kido J, Lee ST and Sariciftci NS, (eds.). Organic and Polymeric Materials and Devices-Optical, Electrical and Optoelectronic Properties. 2002, p. 131-6.
 Feili D, Schuettler M, Doerge T, Kammer S, Hoffmann KP and Stieglitz T. Flexible organic field effect transistors for biomedical microimplants using polyimide and parylene C as substrate and insulator layers. Journal of Micromechanics and Microengineering. 2006; 16: 1555-61.
 PROETex. D8.1 Report on fibre design for different electronic functions (transistors, sensors). 2007.
 Zhou LR, Wu GN, Cao KJ, Luo Y and Ieee. Study on Charge Transport Mechanism in Polyimide Films. 2009, p.800-3.
 Facchetti A, Yoon MH and Marks TJ. Gate dielectrics for organic field-effect transistors: New opportunities for organic electronics. Adv Mater. 2005; 17: 1705-25.
 Quevedo-Lopez MA, Wondmagegn WT, Alshareef HN, Ramirez-Bon R and Gnade BE. Thin Film Transistors for Flexible Electronics: Contacts, Dielectrics and Semiconductors. J Nanosci Nanotechnol. 2011; 11: 5532-8.
 Lee SC, Tai FC, Wei CH and Yu JI. ATR-FTIR and nanoindentation measurements of PMDA-ODA polyimide film under different curing temperature. Materials Transactions. 2007; 48: 1554-7.
 Youngs IJ, Stevens GC and Vaughan AS. Trends in dielectrics research: an international review from 1980 to 2004. Journal of Physics D-Applied Physics. 2006; 39: 1267-76.
 Bonfiglio A, De Rossi D, Kirstein T, et al. Organic field effect transistors for textile applications. Ieee Transactions on Information Technology in Biomedicine. 2005; 9: 319-24.
 Cardoen J. Ontwikkeling van transistor vezels. Master Thesis Universiteit Gent. 2007.
 Ree M. High performance polyimides for applications in microelectronics and fiat panel displays. Macromolecular Research. 2006; 14: 1-33.
 Kiekens P. Advanced and Specialised Fibrous Materials. Ghent, Belgium: Universiteit Gent, 2008.
 Jung KD, Kim YC, Shin H, et al. A study on the carrier injection mechanism of the bottom-contact pentacene thin film transistor. Applied Physics Letters. 2010; 96.
 Kim JH, Min BR, Won J, Park HC and Kang YS. Phase behavior and mechanism of membrane formation for polyimide/DMSO/water system. Journal of Membrane Science. 2001; 187: 47-55.
 Guo MC and Wang XG. SYNTHESIS AND CHARACTERIZATION OF POLYIMIDE WITH MAIN-CHAIN PHOTOSENSITIVE GROUPS AND HYDROXYL SIDE-GROUPS. Acta Polym Sin. 2008: 1113-7.
 Guo MC, Li SN, Wang XG, Liu G and Yi XS. SYNTHESIS AND CHARACTERIZATION OF A POLYIMIDE CONTAINING PHENOLPHTHALEIN GROUPS. Acta Polym Sin. 2012: 278-83.
 Ren HF, Guan Y, He YN, He HF and Wang XG. Polyimide containing isosorbide units: Synthesis and characterization. Acta Polym Sin. 2006: 248-52.
 Maccioni M, Orgiu E, Cosseddu P, Locci S and Bonfiglio A. Towards the textile transistor: Assembly and characterization of an organic field effect transistor with a cylindrical geometry. Applied Physics Letters. 2006; 89.
 Bormashenko E, Pogreb R, Stanevsky O, et al. Mesoscopic and submicroscopic patterning in thin polymer films: Impact of the solvent. Materials Letters. 2005; 59: 2461-4.
 wikipedia. Chemical Solution Deposition. 2013.
 Arfsten NJ, Eberle A, Otto J and Reich A. Investigations on the angle-dependent dip coating technique (ADDC) for the production of optical filters. Journal of Sol-Gel Science and Technology. 1997; 8: 1099-104.
 Van Genabet B. Synthesis and characterisation of copper, polyimide and TIPS-pentacene layers in the development of a solution processed fibrous transistor. Department of Textiles. Gent: Universiteit Gent, 2010.
 Yong-Hoon K, Lee YU, Jeong-In H, Han SM and Han MK. Influence of solvent on the film morphology, crystallinity and electrical characteristics of triisopropylsilyl pentacene OTFTs. Journal of the Electrochemical Society. 2007; 154: H995-H8.
 Kim J, Jeong J, Cho HD, et al. All-solution-processed bottom-gate organic thin-film transistor with improved subthreshold behaviour using functionalized pentacene active layer. Journal of Physics D-Applied Physics. 2009; 42.
 Choi MH, Han SH, Lee SH, Choo DJ, Jang J and Kwon SK. Effect of active layer thickness on environmental stability of printed thin-film transistor. Organic Electronics. 2009; 10: 421-5.
 Mikhailenko SUD, Wang KP, Kaliaguine S, Xing PX, Robertson GP and Guiver MD. Proton conducting membranes based on cross-linked sulfonated poly(ether ether ketone) (SPEEK). Journal of Membrane Science. 2004; 233: 93-9.
 Adachi T and Sakka S. THE ROLE OF N,N-DIMETHYLFORMAMIDE, A DCCA, IN THE FORMATION OF SILICA-GEL MONOLITHS BY SOL-GEL METHOD. J Non-Cryst Solids. 1988; 99:118-28.
 Schwarz A. Analysis of wetting behaviour of an inclined fibre. Kaunas: Kaunas University of Technology, 2005.
 Quere D, Dimeglio JM and Brochardwyart F. SPREADING OF LIQUIDS ON HIGHLY CURVED SURFACES. Science. 1990; 249: 1256-60.
 C. Hemenway/R. Henry/M. Caulton. Physical electronics. New York: Wiley 1967.
 Frenkel J. On pre breakdown phenomena in insulators and electronic conductors. Physical Review, 1938.
 L. Solymar/D. Wals. Electrical properties of materials 6th ed. Oxford: Oxford university press, 1998, p.90-2.
 Someya T, Sekitani T, Iba S, Kato Y, Kawaguchi H and Sakurai T. A large-area, flexible pressure sensor matrix with organic field-effect transistors for artificial skin applications. Proceedings of the National Academy of Sciences of the United States of America. 2004; 101: 9966-70.