Epidermis inspired self-assembled iontronic foam with high sensitivity and broad range

Electronic skin has showcased superior sensing capabilities inspired from human skin. However, most preceding studies focused on the dermis of the skin rather than the epidermis. In particular, the pseudo-porous structural domain of the epidermis increases the skin's tolerance while ensuring its susceptibility to touch. Yet, most endeavors on the porous structures failed to replicate the superior sensing performance of skin-like counterparts in terms of sensitivity and/or detection range. Stimulated by the strategy that the epidermis of the skin absorbs energy while producing ionic conduction to the nerves, this work initiatively introduced an easy-to-produce, and low-cost pressure sensor based on ionic-gel foam, and achieved a high sensitivity (2893 ​kPa⁻¹) within a wide pressure range (up to ∼1 ​MPa), which ranked among the best cases thus far. Moreover, the factors affecting the sensor performance were explored while the sensing principles were enriched. Inspiringly, the plantar pressure measurement by harnessing the as-prepared sensor unveiled an ultra-broad detection range (100 Pa-1 MPa), thus delivering a huge application potential in the field of robot and health monitoring.