(Invited) Multimodal Flexible Sensor System with Wireless Feedback Alarm Function

Abstract

Flexible and stretchable electronics are now widely studied for a next class of electric devices replaced from the silicon-based conventional inflexible devices. In particular, multi-functional sensor sheets can contribute to the applications for Internet of Things concepts applied to infrastructure, vehicles, plants, and human owing to macroscale and conformable covering onto curved and soft surfaces. One of the interesting approaches to use the flexible sensor sheet is a healthcare and medical application to monitor vital signals from skin surface. Because of soft and flexible sensor system, it can be attached onto skin conformally and comfortably, resulting in that more vital signals can be detected unlike conventional wearable watch-based devices. In this application, chemical information such as pH, glucose, sodium ion, and potassium ion levels are very important to monitor as well as physical information including activity, temperature, heartbeat, and electrocardiogram (ECG) signals. Furthermore, simultaneous multiple condition monitoring of physical and chemical information is a next class of wearable devices for convenient and safe human life by integrating with wireless and signal processing circuit systems.To realize the multi-functional flexible sensor system platforms, in this talk, multimodal flexible physical and chemical sensor sheets will be discussed by developing low-cost and macroscale fabrication methods. Especially, ECG, respiration, perspiration, skin temperature, and human activity are monitored by using the developed sensor system. After understanding the fundamental properties and mechanism of the flexible sensors, integrated device applications with several sensors on a flexible film are demonstrated as proof-of-concepts for multi-functional e-skins. Finally, wireless and feedback alarm system integrated with the multimodal flexible sensor sheet are briefly discussed.