Triboelectric Nanogenerator-based smart biomedical sensors for healthcare

Self-powered nanogenerators (NGs) use ambient mechanical energy to power devices, and NGs can replace batteries. The NGs converting mechanical energy into electrical energy utilizing the phenomenon of triboelectrification and electrostatic induction are called Triboelectric Nanogenerators (TENGs). TENGs-based self-powered sensors have gained popularity as biomedical sensors due to their properties. The activities of elderly people with chronic diseases or younger ones doing exercise need continuous health monitoring. Remote healthcare monitoring also requires trustworthy and affordable solutions. For these reasons, self-powered biomedical devices are being developed to address the needs of patients, specifically in the elderly category. This study reviews recent TENG-powered smart and wearable biomedical sensors. We use respiratory, tactile, cardiac, and sweat-based TENG sensors to monitor younger and older patients remotely and at home. Moreover, we also discuss different TENGs and in vivo sensors reported in recent years. Further, we discuss the drawbacks and limitations of the existing designs of TENGs, including poor performance, complex fabrication strategies with a large number of electronic elements, problems with miniaturization, etc. We strongly believe that developing smart and wearable self-powered devices capable of reading physiological data will determine the health monitoring at home for older people in the future.