Self-assembly of dendritic-lamellar MXene/Carbon nanotube conductive film for wearable tactile sensors and artificial skin

A porous structure based on a solution-based approach is highly desired for electrodes in flexible electronics due to the requirements of efficient electron and mass transfer. However, such a structure is largely unexplored for MXene-based electrodes. Here, we developed a solution-based self-assembly system to produce a conductive film with a high void space. Using water evaporation-induced self-assembly, a dendritic-lamellar MXene/carbon nanotube/polyvinylpyrrolidone electrode with high flexibility was prepared. By printing this electrode on hemisphere bumps of natural rubber substrates, a tactile sensor was prepared using face-to-face contacting of the hemisphere bumps. A detection limit of 0.69 Pa and a response time of ∼48 ms were obtained for the sensor, which were demonstrated for voice recognition and pulse measurement. An artificial skin realized a resolution of n2 using 2n connection ports based on the printed MXene/SWCNT/PVP electrode. This solution-based self-assembly for construction of MXene-related composites can be applied to other two-dimensional nanomaterials.