(Invited) Imperceptible Graphene Based Electronic Tattoo Sensors

Abstract

During last decade, there have been advances in wearables with applications in mobile healthcare, athletic, assistive technology, human machine interface and internet of things. However, current wearable sensors and systems have at least one or more of the following drawbacks: they are bulky, expensive, distractive, unsuitable for long term measurement or prone to motion artifact. We present ultrathin graphene based electronic tattoo (GET) sensors with the overall thickness of less than 500 nm. Presented e-tattoo sensors can be laminated on skin like as temporary tattoo and form conformal contact to microscopic texture of the skin. GET is a set of dry sensors with electrode-skin interface impedance comparable to wet gel electrodes that are gold standard in medical applications. Low electrode-skin interface impedance of these e-tattoo sensors results in high signal to noise ratio and high sensing quality. Due to low areal mass density of GET, it attaches to skin without any adhesive or tape, just by Van der Waals force. Presented e-tattoos are both optically and mechanically imperceptible, therefore, they are desirable for applications in prominent areas of appearance such as face. We present the successful demonstration of GET applications for electrocardiography (EEG), electroencephalography (EEG), electromyography (EMG), electrooculography (EOG), skin temperature sensing, skin hydration sensing and human robot interface.