Soft mixed ionic–electronic conductive electrodes for noninvasive stimulation

ABSTRACT A new material, classified as a soft mixed ionic–electronic conductor (MIEC), was fabricated through casting and curing of different ratios of single walled carbon nanotube (SWNTs), hyaluronic acid (HA), and acrylonitrile butadiene copolymer latex (NBR) and developed for noninvasive stimulation for electrotherapeutics. The morphology of the composite yielded high electrical conductivity and retention of elasticity. The interfacial charge transfer of the material showed that by increasing the HA loading the capacitive contribution decreased, while increasing SWNT loading decreased the interfacial resistance. The soft MIEC materials interfacial charge transfer was superior than current state‐of‐the art electrodes on the market. A layered configuration with high HA ratio at the skin interface and high SWNTs ratio at the stainless‐steel interface was created to induce the most optimal charge transfer. These soft MIEC electrodes will be extremely helpful in electrotherapeutic applications to eliminate the need for hydrogels, which can be unsuitable due the their lack long term durability and instability.