MXene/PPy@PDMS sponge-based flexible pressure sensor for human posture recognition with the assistance of a convolutional neural network in deep learning

Abstract

The combination of flexible sensors and deep learning has attracted much attention as an efficient method for the recognition of human postures. In this paper, an in situ polymerized MXene/polypyrrole (PPy) composite is dip-coated on a polydimethylsiloxane (PDMS) sponge to fabricate an MXene/PPy@PDMS (MPP) piezoresistive sensor. The sponge sensor achieves ultrahigh sensitivity (6.8925 kPa−1) at 0–15 kPa, a short response/recovery time (100/110 ms), excellent stability (5000 cycles) and wash resistance. The synergistic effect of PPy and MXene improves the performance of the composite materials and facilitates the transfer of electrons, making the MPP sponge at least five times more sensitive than sponges based on each of the individual single materials. The large-area conductive network allows the MPP sensor to maintain excellent electrical performance over a large-scale pressure range. The MPP sensor can detect a variety of human body activity signals, such as radial artery pulse and different joint movements. The detection and analysis of human motion data, which is assisted by convolutional neural network (CNN) deep learning algorithms, enable the recognition and judgment of 16 types of human postures. The MXene/PPy flexible pressure sensor based on a PDMS sponge has broad application prospects in human motion detection, intelligent sensing and wearable devices.

Advancements in MXene Composite Materials for Wearable Sensors: A Review

“…Moreover, the excellent elasticity and porous characteristics of the PU sponge, combined with MXene's outstanding mechanical properties, endowed the MCG sponge pressure sensor with remarkable stability (maintaining sensing performance stability after 15,000 cycles of reciprocal pressure testing at 3.4 kPa) and rapid response/recovery times (63/40 ms). In another study, Xia et al [97] fabricated MXene/PPy@PDMS (MPP) sponges by coating PDMS sponge frameworks obtained via sacrificial sugar templating with MXene/PPy solution synthesized through in situ polymerization. The evaluation demonstrated that the MPP sponge pressure sensor achieved high sensitivity (6.8925/kPa), short response/recovery times (100/110 ms), excellent stability (5000 cycles), and a low detection limit (below 0.43 Pa) within the pressure range of 0-15 kPa.…”

Anti-Oxidized Self-Assembly of Multilayered F-Mene/MXene/TPU Composite with Improved Environmental Stability and Pressure Sensing Performances

“…The conductive modification of the compressible structure of the pressure-sensitive layer is considered to be one of the strategies to improve the performance of the sensor [16]. The current compressible structures include porous skeleton structures [17,18], cotton or fabric [19,20], nonwoven structures [21], and so on. For example, Cheng et al [22] prepared MXene/PPNs/TPUEM nanofiber mats by the vacuum filtration of poly (styrenemethacrylic acid) @polypyrrole nanospheres (PPNs) and MXene onto a thermoplastic polyurethane electrospun membrane (TPUEM) with a multi-void structure, and assembled a flexible pressure sensor.…”