Waterproof Flexible Pressure Sensors Based on Electrostatic Self-Assembled MXene/NH₂-CNTs for Motion Monitoring and Electronic Skin

Abstract

Flexible wearable sensors to monitor human movement and for electronic skins must exhibit high sensitivity, a wide detection range, and waterproof characteristics. This work reports a flexible, highly sensitive, and waterproof sponge pressure sensor (SMCM). The sensor is made by assembling SiO2 (S), MXene (M), and NH2-CNTs (C) on the backbone of melamine sponge (M). The SMCM sensor exhibits excellent sensitivity (10.8 kPa–1), an ultra-short response/recovery time (40 ms/60 ms), a wide detection range (30 kPa), and an extremely low detection limit (4.6 Pa). Benefiting from layer-by-layer self-assembly, the sensor still exhibits excellent stability after 5000 cycles. In addition, the SMCM sensor also has excellent waterproof performance (a water contact angle of 142°), enabling it to operate unaffectedly under wet conditions. The SMCM sensor can accurately detect small body movements such as pulse and swallowing while also accurately detecting finger and elbow movements. In addition, the sensor can be designed as an array to construct an electronic skin for detecting the magnitude and distribution of external pressure. This work holds great application potential in next-generation electronic skin, fitness detection, and flexible pressure sensors.

Flexible MXene/Nanocellulose Composite Aerogel Film with Cellular Structure for Electromagnetic Interference Shielding and Photothermal Conversion

“…To further confirm the successful preparation of MXene nanosheets, XRD analysis of MAX phase, multilayered MXene, and delaminated MXene were performed. Figure S4b displays that the representative peak of MAX (2θ = 39°) disappeared after etching, and the (002) peak downshifted from ∼8.6 (multilayered MXene) to ∼6.6° (delaminated MXene), suggesting that the space between the lamellar layers increased after etching and ultrasound treatment …”

Flexible Accelerated-Wound-Healing Antibacterial Hydrogel-Nanofiber Scaffold for Intelligent Wearable Health Monitoring

“…3,4 Research into integrating electronic components with skin, referred to as "electronic skin" or "e-skin″, has the potential to revolutionize biomedical applications, encompassing wearable health monitoring, 5,6 regenerative biomaterials, 7 and diagnostic modalities, 8 by enhancing the external perception capabilities akin to human skin. 9 This electronic skin emulates external sensory perception while facing challenges in promoting wound healing, particularly in terms of antibacterial properties, mechanical performance, and microenvironment regulation. 10,11 Hence, from a practical biomedical standpoint, eskin should not only possess reliable mechanical properties, including excellent stretchability and high mechanical strength, but also exhibit intelligent sensing capabilities and diverse biological functions.…”

“…Wearable bioelectronics is a field capable of monitoring intermolecular electron transfer within physiological processes and providing real-time physical and biochemical sensing, establishing a foundation for the development of biomedically applicable bioelectronics. , Skin, as the largest organ, acts as a natural multitier barrier that isolates the external environment, making it an ideal human–machine interface. , Research into integrating electronic components with skin, referred to as “electronic skin” or “e-skin″, has the potential to revolutionize biomedical applications, encompassing wearable health monitoring, , regenerative biomaterials, and diagnostic modalities, by enhancing the external perception capabilities akin to human skin . This electronic skin emulates external sensory perception while facing challenges in promoting wound healing, particularly in terms of antibacterial properties, mechanical performance, and microenvironment regulation. , Hence, from a practical biomedical standpoint, e-skin should not only possess reliable mechanical properties, including excellent stretchability and high mechanical strength, but also exhibit intelligent sensing capabilities and diverse biological functions .…”

Flexible and Wearable Piezoresistive Sensors Based on Double Wrinkled Layers for Motion Monitoring and Human Physiological Signal Monitoring

“…At present, according to different working mechanisms, pressure sensors can be mainly divided into four types, including piezoresistive, , capacitive, − piezoelectric, and frictional. , Among them, piezoresistive sensors are more attractive due to their simple structure, convenient signal acquisition, low noise, low energy consumption, and low manufacturing cost. A variety of conductive materials are used in the preparation of piezoresistive sensors, such as carbon-based materials (carbon black, carbon nanotubes, graphene, − etc. ), metal nanomaterials (gold nanoparticles, , silver nanowires, − etc.…”