All-Printed MXene–Graphene Nanosheet-Based\nBimodal Sensors for Simultaneous Strain and Temperature Sensing

Abstract

Multifunctional\nsensors with integrated multiple sensing capabilities\nhave enormous potential for in situ sensing, structural health monitoring,\nand wearable applications. However, the fabrication of multimodal\nsensors typically involves complex processing steps, which limit the\nchoices of materials and device form factors. Here, an aerosol jet\nprinted flexible bimodal sensor is demonstrated by using graphene\nand Ti₃C₂T_<i>x</i> MXene\nnanoinks. The sensor can detect strain by measuring a change in the\nAC resistive voltage while simultaneously monitoring temperature by\ndetecting the DC Seebeck voltage across the same printed device pattern.\nThe printed bimodal sensor not only expands the sensing capability\nbeyond conventional single-modality sensors but also provides improved\nspatial resolution utilizing the microscale printed patterns. The\nprinted temperature sensor shows a competitive thermopower output\nof 53.6 μV/°C with ultrahigh accuracy and stability during\nboth steady-state and transient thermal cycling tests. The printed\nsensor also demonstrates excellent flexibility with negligible degradations\nafter 1000 bending cycles. The aerosol jet printing and integration\nof nanomaterials open many opportunities to design and manufacture\nmultifunctional devices for a broad range of applications.