Wrist-Worn Capacitive Sensor for Activity and Physical Collaboration Recognition

Abstract

Given the wide and increasing popularity of smart-watches, the wrist is a compelling location for placing sensors. On the other hand, only specific information such as hand/arm motions and selected physiological signals are readily available at the wrist. In this paper, we explore a novel wrist-worn sensing approach that allows information not typically associated with the wrist or the arm to be acquired by exploring the ubiquitous near-field electric phenomena. We first introduce the design of an ultra-low power near-field electric field sensing prototype, which is able to sense $uV$ level potential variation caused by disturbance or movement of the human body in an environment. Then we demonstrate how our prototype can detect motions of various body parts beyond the wrist, such as touch and proximity between users and objects. Finally, a use case related to a collaborative work by two people is recorded by deploying our prototypes both at surrounding objects and on wrists, presenting the feasibility of collaborative work monitoring by sensing the variation of the near field electric field.