Flexible Ti₃C₂T_x MXene/PANI/Bacterial Cellulose Aerogel for e-Skins and Gas Sensing

Abstract

Flexible pressure sensors made of carbon materials have been used in electronic skins (e-skins), whose performance can be enhanced if composite sensing materials are used. Herein, an MXene/polyaniline/bacterial cellulose (MXene/PANI/BC) aerogel sensor has been fabricated through the self-assembly process between the MXene and one-dimensional active material. Combined with fewer-layer or single-layer MXenes, the as-fabricated aerogel could be used as the active layer of the pressure sensor, monitoring tiny motion signals of finger bending, wrist bending, and pulse beating. Bluetooth wireless transmission could also be realized to monitor the real-time spatial pressure distributions on the mobile phone, making the aerogel-based sensor an ideal candidate in e-skins. Meanwhile, the aerogel-based sensor is sensitive toward NH3 due to the unique three-dimensional (3D) structure of the aerogel and the abundant terminal groups (such as −O, −OH, and −F) of the MXene in the system that ensure efficient electronic transfer for the sensing process and create active sites for the absorption with the target gas. This work offers a versatile platform to develop MXenes to fabricate 3D composite aerogels for high-performance flexible multiple sensors.

Assessment of Occlusal Force and Local Gas Release Using Degradable Bacterial Cellulose/Ti3C2Tx MXene Bioaerogel for Oral Healthcare

“…These results clearly suggest a synergistic effect between cellulose, which improves the gas response of the biocomposite, and MXene. The cellulose fiber possesses rich −OH groups and easily forms hydrogen bonds with the abundant functional groups on the surface of MXene, which may lead to significant changes in carrier density and enhance the response. , In addition, the bioaerogel with a 3D porous structure provides a larger surface area and generates more effective NH 3 molecule adsorption sites. − Considering this, we anticipate that the proposed BC/MXene aerogel-based sensor will effectively sense trace NH 3 molecules and enrich the application fields of MXene materials.…”

Lightweight Nanofibrous Crosslinked Composite Aerogels with Controllable Shapes and Superelasticity for Pressure Sensors

“…After elaborate calculation, the S of the as-prepared pressure sensor was high as 0.53 kPa −1 in a wide pressure range of 0.1-3.62 kPa. It was quite difficult for most aerogel-based pressure sensors to retain a high sensitivity and excellent linear response in such a large range, [23][24][25][26] so our pressure sensor was an ideal candidate with broad application prospects in encrypted information transmission. Moreover, the linear sensitivity of composite carbonized aerogels with different shapes as pressure sensor in a pressure range of 0.1-3.62 kPa are provided as Figure S6, Supporting Information.…”

Interface Growth of PANI-ZnO Nanohybrids on a Self-Formed Grapefruit Peel Aerogel to Construct a Quick Self-Restored Gas Sensor

“…30 Cellulose aerogel materials with a porous surface with high specificity can improve gas sensing performance. 31,32 structural stability and high gas detection remains a great challenge.…”

“…to ensure efficient electron transfer for sensing processes while creating active sites for target gas absorption. 31,32 In addition, some PANI NPs are in direct contact with ZnO nanorods to form p−n heterojunctions, which reduce the band gap of each other and further increase the electron transfer rate and improve the response rate of the sensor to the gas (Figures S6 and S7). 25,46 A higher resistance change and lower response and recovery times of PANI-ZnO@GPA further validated the enhanced sensing role of these structures (Figure S8).…”

“…Especially, PANI-ZnO nanohybrids exhibit lower detection limits, faster response times, and more stable sensing signals compared to other component sensors. , However, PANI-ZnO nanohybrids without a supporting template are prone to agglomeration and difficult to use effectively. − Poly­(ethylene oxide) and chitin nanowhiskers were used to improve the dispersion of PANI-ZnO nanocomposites, which can enhance gas sensing ability; however, those templates still show weak structural stability . Cellulose aerogel materials with a porous surface with high specificity can improve gas sensing performance. , However, constructing PANI-ZnO nanocomposites based on cellulose aerogels with structural stability and high gas detection remains a great challenge.…”