Wearable biosensors are smart electronic devices that can be worn on the body as implant or accessories. Recent advances in microelectronics, telecommunications and sensor manufacturing have opened up new possibilities for using wearable biosensors to continuously monitor an individual’s body. However, while many commercially available wearable electronics can track users’ physical activities, devices which can provide insightful view of user’s health status at molecular level need more development. Moreover, although some commercial hand-held analyzers enable glucose or lactate detection, most of these devices rely on blood samples. Neither finger-prick nor invasive sensors (such as a needle embedded under skin) is desired for wearable biomedical applications. A key advantage offered by wearable biosensors is continuous monitoring, which has great potential in many cases. For example, optimum diabetes management needs regular glucose monitoring, and a trend of glucose level is more meaningful than an accurate data point. Besides glucose monitoring, real-time detection of some pathogens in body fluids can alert about the possible onset of certain diseases.
Here, we demonstrate highly sensitive and conformal In2O3 nanoribbon FET biosensors with fully integrated on-chip gold side gate, which have been laminated onto various surfaces, such as artificial arms and watches, and have enabled glucose detection in various body fluids, such as sweat and saliva. The non-invasive glucose detections in human body fluids, such as tears and sweat, and the sensing on artificial skin and eye replicas are demonstrated. Therefore, this type of devices are a highly sensitive platform for not only glucose detections but also many other types of sensing applications.