• Tuukkanen, Sampo
• Kallio, Pasi
• Viehrig, Marlitt
• Rajala, Satu

Abstract

Cellulose based nanomaterials, generally known as nanocellulose [1], are interesting renewable bio-based nanomaterials which have potential applications in material sciences, electronics and biomedical engineering and diagnostic. A strong ability to form light-weight, highly porous, entangled networks makes nanocellulose suitable substrate or membrane material for various applications, such as supercapacitors [2,3].It was proposed already in 1950’s, that wood has piezoelectric properties initiating from the highly crystalline assemblies of cellulose chains [4]. Experimental evidence of the piezoelectricity of cellulose nanocrystals (CNC) was reported only very recently [5,6]. Cellulose nanofibrils (CNF), produced by a mechanical homogenizing process from cellulose fibers, contain both crystalline and amorphous regions. CNC can be obtained from CNF by removal of amorphous regions using hydrolysis e.g. in sulfuric acid.Here, we report the experimental results on piezoelectricity of nanocellulose films prepared using different methods. The piezoelectric sensitivity of prepared sensor elements is measured using in-house built measurement setup equipped with a mechanical shaker and charge amplifier [7]. A randomly oriented CNF film (prepared by pressure filtering from aqueous CNF dispersion) showed piezoelectric sensitivities of 2-7 pC/N [8,9], which is between the piezoelectric coefficients of quartz (2.3 pC/N) and polyvinylidenefluoride (PVDF, -30 pC/N). Initial results from the nanocellulose based composite films gives promises for biomedical applications of nanocellulose based piezoelectric sensors. Keywords: Nanocellulose, piezoelectric sensor, cellulose nanofibrils, polyvinylidenefluoride[1]MOON, R. J., MARTINI, A., NAIRN, J., SIMONSEN, J. & YOUNGBLOOD, J. 2011. Cellulose nanomaterials review: structure, properties and nanocomposites. Chem Soc Rev. 40(7), 3941-3994.[2]TUUKKANEN, S., LEHTIMAKI, S., JAHANGIR, F., ESKELINEN, A.-P., LUPO, D. & FRANSSILA, S. 2014. Printable and disposable supercapacitor from nanocellulose and carbon nanotubes. In: Proceedings of the 5th Electronics System-Integration Technology Conference (ESTC). IEEE; 1-6. [3]TORVINEN, K., LEHTIMÄKI, S., KERÄNEN J. T., SIEVÄNEN, J. , VARTIAINEN, J.,HELLÉN, E., LUPO, D., & TUUKKANEN, S. 2015. Pigment-cellulose nanofibril composite and its application as a separator-substrate in printed supercapacitors. Electron Mater Lett., 11(6), 1040-1047.[4]FUKADA, E. 1955. Piezoelectricity of Wood. J Phys Soc Japan., 10, 149-154.[5]CSOKA, L., HOEGER, I. C., ROJAS, O. J., PESZLEN, I., PAWLAK, J. J. & PERALTA, P. N. 2012. Piezoelectric effect of cellulose nanocrystals thin films. ACS Macro Lett., 1(7), 867-870.[6]FRKA-PETESIC, B., JEAN, B. & HEUX, L. 2014. First experimental evidence of a giant permanent electric-dipole moment in cellulose nanocrystals. EPL (Europhysics Lett., 107(2), 28006.[7]RAJALA, S., METTANEN, M. & TUUKKANEN, S. 2015. Structural and Electrical Characterization of Solution-Processed Electrodes for Piezoelectric Polymer Film Sensors. IEEE Sens J. (Accepted for publication).[8]RAJALA, S., VUORILUOTO, M., ROJAS, O. J., FRANSSILA, S. & TUUKKANEN, S. 2015. Piezoelectric sensitivity measurements of cellulose nanofibril sensors. In: XXI IMEKO 2015 World Congress “Measurement in Research and Industry” Conference Proceedings. 2-6.[9]TUUKKANEN, S. & RAJALA, S. 2015. A Survey of Printable Piezoelectric Sensors. In: Proceedings of IEEE Sensors 2015 Conference., 1426-1429.

Topics

• porous
• nanocomposite
• impedance spectroscopy
• dispersion
• polymer
• amorphous
• Carbon
• nanotube
• thin film
• composite
• wood
• cellulose