Maximizing Electron Channels Enabled by MXene Aerogel for High-Performance Self-Healable Flexible Electronic Skin

Abstract

Among the increasingly popular miniature and flexible smart electronics, two-dimensional materials show great potential in the development of flexible electronics owing to their layered structures and outstanding electrical properties. MXenes have attracted much attention in flexible electronics owing to their excellent hydrophilicity and metallic conductivity. However, their limited interlayer spacing and tendency for self-stacking lead to limited changes in electron channels under external pressure, making it difficult to exploit their excellent surface metal conductivity. We propose a strategy for rapid gas foaming to construct interlayer tunable MXene aerogels. MXene aerogels with rich interlayer network structures generate maximized electron channels under pressure, facilitating the effective utilization of the surface metal properties of MXene; this forms a self-healable flexible pressure sensor with excellent sensing properties such as high sensitivity (1,799.5 kPa–1), fast response time (11 ms), and good cycling stability (>25,000 cycles). This pressure sensor has applications in human body detection, human–computer interaction, self-healing, remote monitoring, and pressure distribution identification. The maximized electron channel design provides a simple, efficient, and scalable method to effectively exploit the excellent surface metal conduction of 2D materials.

Ti3C2Tx MXene-Based Multifunctional Tactile Sensors for Precisely Detecting and Distinguishing Temperature and Pressure Stimuli

“…When Ti 3 C 2 T x MXene is engineered into a 3D porous network, its thermal conductivity can be further reduced, which would allow a stable temperature gradient across the 3D structure to be quickly reached and easily maintained upon exposure to temperature stimuli, thereby ensuring a stable thermoelectric voltage output. Meanwhile, the electrical resistance of the 3D MXene structure can efficiently respond to pressure on the basis of deforming the conducting network, benefiting thermoelectric and piezoresistive applications. , In addition, the excellent electrical conductivity of MXene can contribute to the ultralow noise and high signal-to-noise ratio of the output electrical signals, which are crucial for achieving a high-resolution sensing performance. More importantly, the hydrophilic surface moieties (e.g., -OH) on Ti 3 C 2 T x MXene sheets make them easily processable, facilitating facile device fabrications. − Therefore, despite the low S T value, Ti 3 C 2 T x MXene is likely to provide an opportunity to develop dual-mode temperature–pressure sensors with large-scale application potentials.…”

“…Meanwhile, the electrical resistance of the 3D MXene structure can efficiently respond to pressure on the basis of deforming the conducting network, benefiting thermoelectric and piezoresistive applications. 20,45 In addition, the excellent electrical conductivity of MXene can contribute to the ultralow noise and high signal-to-noise ratio of the output electrical signals, which are crucial for achieving a highresolution sensing performance. More importantly, the hydrophilic surface moieties (e.g., -OH) on Ti 3 C 2 T x MXene sheets make them easily processable, facilitating facile device fabrications.…”

MXene‐Based Flexible Sensors: Materials, Preparation, and Applications

“…[22] Temperature and humidity sensors can sense temperature and humidity changes in the environment and assume an important role in multifunctional smart devices. [17b,23] MXene-based flexible sensors have a wide range of applications in various fields, especially in wearable devices, [24] electronic skin, [25] smart healthcare, [26] environmental monitoring, [27] and food safety. [28] Wearable devices need to be in direct contact with human skin for detecting various physiological signals of the human body, and the preparation of soft, comfortable, safe and efficient flexible sensors is the key to this application area.…”

Inserting an “atomic trap” for directional dopant migration in core/multi-shell quantum dots

“…4,28 Additional challenges to control and study the dopant migration behavior pertains to limited analytical techniques available to the detection of the location and distribution of low concentration dopant ions (generally less than ve percent) in NCs with high spatial and temporal resolution at the nanoscale. 20,[29][30][31] Dopant ions inside NC lattice are extrinsic point defects, which could entail a signicant local distortion of the structure, especially with a large size mismatch with the host substitutional sites. Therefore, thermodynamically, the point defects can migrate to more ideal substitutional sites with smaller size mismatch.…”