Review of MXene-based Resistance Pressure Sensors for Vital Signs Monitor

Various 2D functional materials were studied to evaluate their suitability for a variety of applications, such as energy storage devices, electronic devices, sensors, etc. Among many sensors, pressure sensors are widely used in healthcare, automobiles, industrial automation, and robotic electronic skin applications, etc. Pressure sensors work on different principles. Among them, the piezoresistance principle is more relevant for 2D materials-based pressure sensors. Among many 2D materials classes, MXenes are the latest materials which have been studied for different applications in the past few years. MXenes exhibit a piezoresistance effect by a reduced lattice interlayer distance, enhanced surface contact area, and increased strain under applied pressure. In the past few years, many researchers have studied MXene-based resistance pressure sensors (RPSs) for a variety of applications in healthcare. Here, a review of the recent literature on vital signs (heart rate, blood pressure, respiration rate) monitoring, and body language analysis by MXene-based RPSs is systematically reported. Vital signs give information about the homeostasis status of the human body. Further, various synthesis methods for different MXenes and their composites functional materials preparation, sensor fabrication geometries, such as sensors with and without a spacer layer, and matrix array sensors have been reported. The MXenes and their composite-based RPSs vital signs monitoring performances are also compared with other 2D graphene materials, for a quick understanding.