Biocellulose (BC) is a biocompatible material produced by the Glucanacetobacter xylinus bacteria [1]. It is renewable and biodegradable, being used in medical applications, is stable up to 260 °C and its dielectric constant is in the range 1.6 − 1.9 [2]. BC-based materials are being studied for applications in organic electronics, either as substrate or as dielectric.
In this communication we report on the fabrication and characterisation of organic field-effect transistors incorporating biocellulose, chitosan or composites based on these materials, either as substrates or as dielectric. Organic semiconductors such as RR-poly(3-hexylthiophene) (P3HT) or poly(9,9-dioctylfluorene-alt-bithiophene), deposited by spin coating or by inkjet, and thermally deposited pentacene, are being used in such devices.
Figure 1 shows the output characteristics of a transistor prepared with P3HT and a 50 micron thick chitosan film as dielectric.
Acknowledgments: We thank FCT under the contracts PTDC/CTM/102144/2008 and PTDC/QUI/65474/2006 for financial support.

References
[1] É. Pecoraro, D. Manzani, Y. Messaddeq, S. J. L. Ribeiro, in Monomers, Polymers and Composites from Renewable Resources, (Eds: B. Mohamed Naceur, G. Alessandro), Elsevier, Amsterdam 2007, 369.
[2] L. Alcácer, J. Morgado, Q. Ferreira, É. Pecoraro, C. P. Neto, A. J. D. Silvestre, C. S. R. Freire, E. Trovatti, S. C. M. Fernandes, in EUROCON 2011, Lisboa, 2011.