Ultra-conductive and transparent epidermal electrodes for simultaneous dual-mode assessment of brain function

A Stretchable and Sweat-Adhesive 3D Graphene Eutectogel Electrode for EMG Monitoring

“…In recent years, wearable devices have made remarkable progress and have been widely used in different fields, such as human–computer interactions, healthcare, and drug delivery. − An epidermal electrode is a kind of wearable device and can collect electrophysiological signals, including electroencephalography (EEG), electrocardiography (ECG), electrooculography (EOG), and electromyography (EMG). − EMG is derived from electrical potential changes of muscle cells or muscle tissues during activity, which is used for fatigue assessment and relief, sports training, and prosthesis control. − However, epidermal electrodes no longer fit closely to skin after sweating or a period of use, which creates motion artifacts, reduces the signal-to-noise ratio (SNR), and makes it difficult to detect weak EMG. , In addition, human skin deforms with body movement. Dry electrodes do not adapt to the deformation and separate from skin, which cannot stably detect signals and causes discomfort. , Commercial gel electrodes usually reduce adhesion and conductivity after prolonged use due to water loss, which poses a challenge for long-term reusable electrodes. − Eutectic gels are a type of ionic gels, which have great adhesion and stretchability .…”