Fully Elastomeric Fingerprint-Shaped Electronic Skin Based on Tunable Patterned Graphene/Silver Nanocomposites.

Multifunctional electronic skins (e-skins), which mimic the somatosensory system of human skin, have been widely employed in wearable devices for intelligent robotics, prosthetics, and human health monitoring. Relatively low sensitivity and severe mutual interferences of multiple stimuli detection have limited the applications of the existing e-skins. To address these challenges, inspired by the physical texture of the natural fingerprint, a novel fully elastomeric e-skin is developed herein for highly sensitive pressure and temperature sensing. A region-partition strategy is utilized to construct the multifunctional fingerprint-shaped sensing elements, where strain isolation structure of indurated film patterns are further embedded to enhance the sensitivity and effectively reduce mutual interferences between the differentiated units. The fully elastomeric graphene/silver/silicone rubber nanocomposites are synthesized with tunable properties including conductivity and sensitivity to satisfy the requirements of highly sensitive pressure and temperature sensing as well as stretchable electrodes. Remarkable progress in sensitivities for both pressure and temperature, up to 5.53 kPa in a wide range of 0.5-120 kPa and 0.42% °C in 25-60 °C, respectively, are achieved with the inappreciable mutual interferences. Further studies demonstrate the great potential of the proposed e-skin in the next-generation of wearable electronics for human-machine interfaces.