Chahrazad BENBALIT(1,2), Olivera SCHEUBER(1), Eleonora FRAU(1), and Silvia SCHINTKE(1)*
(1) Laboratory of Applied NanoSciences, Department of Industrial Technologies, HEIG-VD, HES-SO // University of Applied Sciences Western Switzerland (HES-SO), CH-1401 Yverdon-les-Bains, Switzerland
(2) Institut UTINAM, UMR 6213 CNRS-UBFC, Université de Bourgogne Franche-Comté (UBFC), F-25030 Besançon Cedex, France
Flexible electrodes play an increasing role for medical applications, such as ECG (electrocardiography) or TENS (Transcutaneous electrical nerve stimulation) due to comfort in use and thus their suitability for health monitoring under movement and during sport. Polymers, such as polyvinylidene fluoride (PVDF), are promising for the development of fabrication methods and materials for such application cases, as stable flexible thin polymer
membranes can be produced at large scale. We have compared different up-scalable fabrication techniques of thin electrode membranes based on PVDF as a function of silver nanowire concentration, using electrospinning, spincoating, and drop-casting techniques. The produced membranes and thin films were investigated by electrical four-point probing, optical microscopy, atomic force microscopy, as well as by stability tests under bending, and water exposure. We show, that a combination of electrospinning and spin-coating presents a reliable method for the fabrication of AgNW-PVDF based flexible nanofiber membrane electrodes (NMEs). Our nanofiber membrane electrodes (NMEs) exhibit a 10 times lower sheet resistance than AgNW-PVDF
thin film electrodes (TFEs) produced for comparisons by a combination of spincoating and dropcasting using the same amounts of AgNWs. Upon immersion in water for up to 48 hours, we do not detect any nanowire release or decomposition of the fabricated electrodes, which is promising in view
of application of the AgNW-PVDF composite electrodes in humid environment.
[Submitted: 2020-01-22, Accepted: 2020-04-07, Online: 2021-01-05]