Electrospun gelatin nanofiber based self-powered bio-e-skin for health care monitoring

Progress on smart self-powered electronic skin (e-skin) presents unique opportunities to detect and discriminate static human physiological signals and dynamic tactile stimuli. Nevertheless, development of piezoelectric materials possessing adequate flexibility, light weight, ease of large-area processing, low cost and environmental safety are attractive but remains a challenging choice for next-generation pressure/force sensors and mechanical energy harvesters. Here, we design a wearable bio-inspired piezoelectric pressure sensor (i.e., bio-e-skin) from structurally stable fish gelatin nanofibers (GNFs) using large area compatible electrospining technology. Owing to superior mechanosensitivity (similar to 0.8 V kPa(-1)), the bio-e-skin can mimic spatiotemporal human perception and monitors real-time human physiological signals in non-invasive rational strategy. More importantly, nanoscale ferro-and piezo-electricity (d(33)similar to-20 pm/V) in GNFs, realized by piezoresponse force microscopy allow the bio-e-skin to be self-powered with excellent operational stability (over 108,000 cycles) and anti-fatigue (over 6 months) properties which solve the complication of external power supply for pressure sensing applications.