COMMUNICATION © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim (1 of 5) 1600251 wileyonlinelibrary.com Fully Printed Electrodes on Stretchable Textiles for Long-Term Electrophysiology Eloïse Bihar, Timothée Roberts, Esma Ismailova, Mohamed Saadaoui, Mehmet Isik, Ana Sanchez-Sanchez, David Mecerreyes, Thierry Hervé, Jozina B. De Graaf, and George G. Malliaras* Dr. E. Bihar, Dr. E. Ismailova, Prof. G. G. Malliaras Department of Bioelectronics Ecole Nationale Supérieure des Mines CMP-EMSE MOC, 880, route de Mimet, 13541 Gardanne, France E-mail: malliaras@emse.fr Dr. E. Bihar, T. Roberts, Dr. T. Hervé Microvitae Technologies Hôtel Technologique Europarc Sainte Victoire Bâtiment 6 Route de Valbrillant, 13590 Meyreuil, France Dr. E. Bihar, Dr. M. Saadaoui Department of Flexible Electronics Ecole Nationale Supérieure des Mines CMP-EMSE 880, route de Mimet, 13541 Gardanne, France T. Roberts, Dr. J. B. De Graaf Aix Marseille Univ CNRS, ISM, Marseille, France Dr. M. Isik, Dr. A. Sanchez-Sanchez, Prof. D. Mecerreyes POLYMAT University of the Basque Country UPV/EHU Joxe Mari Korta Center Avda. Tolosa, 72, 20018 Donostia-San Sebastian, Spain DOI: 10.1002/admt.201600251 and allergic reactions from the adhesive used to fix them on the skin. [5] They are also not suitable for long-term measure- ments due to the drying of the gel. [6] To find alternatives, many studies explored electrodes embedded in or deposited on textiles. [7] Textile electrodes can be fabri- cated by integrating conducting yarns into the textile, [8,9] by dip-coating the fibers, [10] or by deposition of conducting materials on the textile. [11] The latter approach, coupled with a direct deposition technique such as inkjet printing, offers great versatility and has the potential to lead to customizable electrodes for health monitoring. To date, however, only a few studies reported the use of inkjet for the fabrication of wearable electrodes for health monitoring. [12,13] Inkjet technology is an additive technology which permits to design customizable electrodes with reduced manufacturing costs. It offers many advantages such as compatibility with a wide range of substrates, small number of fabrication steps, low materials waste, and the possibility to integrate this tech- nique in a roll-to-roll process, making production efficient and inexpensive. In this work we report the fabrication of fully printed, wearable electrodes using inkjet technology by printing the conducting polymer PEDOT:PSS on a commercial stretchable textile. A commercially available pantyhose (100 wt% poly- amide) was chosen as the substrate, as it offers a high level of stretchability. We chose PEDOT:PSS as the conducting layer due to its biocompatibility, [14] and its mixed ionic/electronic conductivity, which yields high quality cutaneous contacts. [15] We further printed an ionic liquid gel to improve the contact between the conducting polymer and skin, as such gels have been shown to lead to high quality contacts with excellent long- term stability. [16] We record electrocardiograms (ECG) from a volunteer and demonstrate recordings that are stable and rather insensitive to motion artifacts, paving the way for the fabrication of low cost, customizable electrodes for cutaneous electrophysiology. The printed electrode geometry (Figure 1) consists of a round disk with a diameter of 1 cm, similar to that of a com- mercial Ag/AgCl electrode, connected to a square contact pad with area of 1 cm 2 . We inkjet-printed several layers of the con- ducting ink (Figure 2) and obtained electrodes with a color that became more apparent as the quantity of conducting material added onto the textile increased. As seen in Figure 2b, the elec- trical resistance of a 1 cm 2 PEDOT:PSS square decreased with Fully printed electrodes consisting of a conducting polymer and an ionic liquid gel are fabricated on a stretchable textile. They are shown to record cardiac activity while the wearer is moving and for long periods of time, paving the way for the development of low-cost devices for continuous health monitoring. Cutaneous devices for health monitoring are attracting a great deal of interest in both industry and academia. Recent advances on the deposition of electronic materials onto textiles are generating a considerable effort focused on the integra- tion of electrical health monitoring systems into clothing. [1–3] Such autonomous, wearable monitoring systems allow a better patient comfort during daily use. They aim to provide early diagnosis of cardiovascular diseases (CVDs), such as arrhyth- mias and can be used for prevention of heart-related problems and related deaths. [4] Existing commercial devices for infant and adult health monitoring use wet (gel-assisted) Ag/AgCl electrodes but these electrodes cause discomfort, and in some cases, skin irritation www.advmattechnol.de Adv. Mater. Technol. 2017, 1600251 www.advancedsciencenews.com