Hierarchical MXene@ZIF-67 Film Based High Performance Tactile Sensor with Large Sensing Range from Motion Monitoring to Sound Wave Detection

Conductive two-dimensional transition metal carbides and nitrides (MXenes) as active materials have demonstrated significant promise for applications in wearable electronic devices. However, the intrinsic high conductivity and poor structural stability of MXenes severely limits its application as a high-performance flexible tactile sensor. To overcome these disadvantages, an interlayer hierarchical MXene/MOFs film was synthesized by intercalating poorly conductive ZIF-67s octahedron crystals between highly conductive MXene nanosheets by vacuum-assisted filtration. The alternating MXene and MOFs layers provided a 3D, interconnected conductive network that enhanced the variation range of the conductive path. The fabricated flexible sensing device featuring the MXene/MOFs hybrid active layers exhibited excellent sensing performance, with a sensitivity of 110.0 kPa(-1), a fast response/recovery time of 15 ms/15 ms, and a broad pressure-detection range of 0.0035-100 kPa. Owing to these merits, the fabricated sensor was capable of monitoring diverse stimuli over a large pressure range, such as recognizing finger movements, eyes blinking, pulses, and vibrations from musical instruments.