Reduced Graphene Oxide Tattoo as Wearable Proximity Sensor

Abstract

AbstractThe human body is punctuated with wide array of sensory systems that provide a high evolutionary advantage by facilitating formation of a detailed picture of the immediate surroundings. The sensors range across a wide spectrum, acquiring input from noncontact audiovisual means to contact‐based input via touch and taste. The ambit of sensing can be extended further by imparting the body with increased noncontact sensing capability through the phenomenon of electrostatics. Here, a graphene‐based tattoo sensor is presented for proximity sensing, employing the principle of electrostatic gating. The sensor shows a remarkable change in resistance upon exposure to objects surrounded with static charge on them. Compared to prior work in this field, the sensor demonstrates the highest recorded proximity detection range of 20 cm. It is ultrathin, highly skin conformal, and comes with a facile transfer process such that it can be tattooed on the human skin, unlike other graphene‐based proximity sensors reported before. Present work details the operation of wearable proximity sensor while exploring the effect of mounting body on the working mechanism. A possible role of the sensor as an alerting system against unwarranted contact with objects in public places especially during the current COVID‐19 pandemic is also explored.