From Event: SPIE Smart Structures + Nondestructive Evaluation, 2023
From smart skins to human-machine interfaces, soft conductive materials have immense potential in wearable applications because of their conformity to the human skin. These materials may be adapted for healthcare devices and sensing functionalities, as well as for rehabilitation purposes like surface functional electrical stimulation (sFES), the process of inducing contractions in paralyzed muscles with electric currents. However, variabilities in muscle distribution among individuals pose new challenges against the development of wearable and personalized sFES platforms. To account for the intricate differences between muscles on different sites of the body, we developed a novel material to actualize stimulation electrodes that are adaptable to be of any shape and size, with self-adhesive properties to ensure conformity to body morphology and guarantee stimulation signal stability. The bio-based polymer of carboxymethyl cellulose is used for the hydrogel matrix due to its water solubility, along with poly(3,4- ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as the conductive additive and tannic acid as the adhesive additive. A mild and biocompatible gelation method involving hydrogen bonds is implemented via the addition of phytic acid, forming the printed hydrogel for the bioelectronic interface within minutes. Compared with conventional stimulation electrodes, the printable hydrogel electrodes can induce muscle movement during sFES with better precision and accuracy.
© (2023) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jia Xi Mary Chen, Terek Li, Zia Saadatnia, Milos R. Popovic, and Hani E. Naguib, "Skin-printable and self-adhesive hydrogel electrodes for functional electrical stimulation therapy," Proc. SPIE 12485, Nano-, Bio-, Info-Tech Sensors, and Wearable Systems 2023, 124850B (Presented at SPIE Smart Structures + Nondestructive Evaluation: March 14, 2023; Published: 18 April 2023); https://doi.org/10.1117/12.2663078.
