Graphene e-tattoos for unobstructive ambulatory electrodermal activity sensing on the palm enabled by heterogeneous serpentine ribbons

Abstract

Electrodermal activity (EDA) is a popular index of mental stress. State-of-the-art EDA sensors suffer from obstructiveness on the palm or low signal fidelity off the palm. Our previous invention of sub-micron-thin imperceptible graphene e-tattoos (GET) is ideal for unobstructive EDA sensing on the palm. However, robust electrical connection between ultrathin devices and rigid circuit boards is a long missing component for ambulatory use. To minimize the well-known strain concentration at their interfaces, we propose heterogeneous serpentine ribbons (HSPR), which refer to a GET serpentine partially overlapping with a gold serpentine without added adhesive. A fifty-fold strain reduction in HSPR vs. heterogeneous straight ribbons (HSTR) has been discovered and understood. The combination of HSPR and a soft interlayer between the GET and an EDA wristband enabled ambulatory EDA monitoring on the palm in free-living conditions. A newly developed EDA event selection policy leveraging unbiased selection of phasic events validated our GET EDA sensor against gold standards.

Technology Roadmap for Flexible Sensors

“…A particularly challenging issue within the scope of soft-hard interfaces is interconnection, which is especially a concern for system integration . In particular, wearable and implantable sensors can be made ultrathin, soft, and stretchable, but poor mechanical strength challenges reliable connection with the rest of the system. , Moreover, sensor arrays ( e.g. , microelectrode arrays for brain mapping) face additional challenges in connecting high-density thin wires across long distances of soft-hard transition.…”

Applications of Graphene in Five Senses, Nervous System, and Artificial Muscles

“…Flexible pressure sensors can evaluate the physiological behaviors, , e.g., the tiny motions of surgical robots and subtle arterial pulse signals. , The ventricular arrhythmia and fibrillation can be captured by magnetoelastic sensor . The graphene tattoos have been developed for wearable electronics with advantages of breathability. , …”

“…330 The graphene tattoos have been developed for wearable electronics with advantages of breathability. 331,332 Second, the data fusion of two types of sensors can provide precision medical healthcare by real-time monitoring. Human−machine interaction result from the synergy of tactile sensing and electrooculography.…”

Human–Machine Interaction via Dual Modes of Voice and Gesture Enabled by Triboelectric Nanogenerator and Machine Learning

“…Nowadays, the rapid development of artificial intelligence and the Internet of Things (IoT) has brought great changes to people’s lives, and human–machine interaction sets application requirements and research ideas for artificial intelligence and the Internet of Things (IoT). − The technology of how to improve the efficiency of communication between human and machine is the most difficult problem for the researchers to overcome, in which the communication system − connecting human and machine is particularly important. Nowadays, there are two main methods of human–machine interaction: voice–machine interaction − and gesture–machine interaction. − Voice signals contain rich character information on humans and are easy to use, so people can use voice signals to make and realize accurate commands.…”