Template-Free Preparation of Highly Sensitive Flexible Pressure Sensors with Microtaper Structure by MXene Modification

In recent years, flexible pressure sensors have garnered significant attention for their potential applications in human-machine interfaces, medical monitoring, and electronic skin. However, the microstructure of the sensitive layer often relies on external templates, resulting in a complicated and costly preparation process. Additionally, the existing conductive networks are challenging to combine high sensitivity and a wide detection range due to uneven dispersion of fillers or weak interfacial bonding. In this paper, carboxylated carbon nanotubes (MWCNTs-COOH)/thermoplastic polyurethane (TPU) composite films with conical microstructure on the surface were directly prepared without an external template by optimizing the parameters of the electrostatic spinning process (RPS). The conductive network and its mechanical properties were enhanced by hydrogen bonding between MXene and TPU. This improved the sensitivity and increased the detection range simultaneously. Experimental findings demonstrate that the sensor demonstrates a sensitivity of up to 443.63 kPa–1 within the range of 4 kPa, a detection limit as low as 2 Pa, respectively, and is capable of stable operation across a wide range of 266 kPa. Furthermore, the sensor demonstrates remarkable performance in scenarios such as human physiological signal monitoring and gesture recognition, thereby substantiating its practical value in the domains of medical health monitoring and human-computer interaction.