Highly Sensitive Multifunctional Electronic Skin Based on Nanocellulose/MXene Composite Films with Good Electromagnetic Shielding Biocompatible Antibacterial Properties

Abstract

Electronic skin has aroused extensive research interest due to high similarity with human skin. Realizing a multifunctional electronic skin that is highly consistent with skin functions and endowed with more other functions is now a more urgent need and important challenge. Here, we use 2,2,6,6tetramethylpiperidinyl-1-oxyl (TEMPO)-oxidized cellulose nanofibril (TOCN) dispersion and highly conductive Ti 3 C 2 T X dispersion to prepare TOCN/Ti 3 C 2 T X composite film through vacuum-assisted filtration. The obtained composite film imitating the nacre-like lamellar structure of natural shells has good mechanical properties (124.6 MPa of tensile strength). Meanwhile, the composite film also showed excellent electromagnetic shielding performance (36 dB), biocompatibility, and antibacterial properties. In addition, the piezoresistive sensor assembled from the composite film exhibited a high sensitivity (11.6 kPa −1 ), fast response and recovery time (≤10 ms), ultralow monitoring limit (0.2 Pa), and long-term stability (>10 000 cycles). It also could detect human daily activities such as finger bent, chewing, and so on.

Forward polarization enhanced all-polymer based sustainable triboelectric nanogenerator from oriented electrospinning PVDF/cellulose nanofibers for energy harvesting

“…S2†) showed that the specific surface area of TOCN aerogel film was up to 97.3 m 2 g −1 and its average pore diameter was 16.4 nm, indicating that it mainly contained rich mesopores which was beneficial to improve the performance of TENG. FTIR results showed that typical characteristic peaks 30 corresponded to stretching vibrations of –OH (3345 cm −1 ), C–H (2910 cm −1 ), CO (1607 cm −1 ), and C–O (1055 cm −1 ) respectively in Fig. S3 †.…”

“…For the increase of thickness of OE PVDF, the thicker lm per unit triboelectric active area can provide more internal surface area to store electrostatic charge, so as to improve the overall electrostatic charge density and output performance of the OE PVDF lm. 30 When the electrospinning time was prolonged by three times (i.e., the thickness of the obtained OE PVDF lm was increased from about 35 mm to about 103 mm by three times), the output voltage of the corresponding device was increased by 2.42 times under the same conditions. These results suggested that increasing the area and thickness of the OE PVDF lm were effective strategies to improve the energy harvesting.…”

Nanocellulose-Based Nanocomposites for Sustainable Applications: A Review

“…Self-healing nanocomposite films with superior mechanical strength (409% increase compared to pure PVA and high toughness up to 407.1%) and excellent adhesion (9670 times greater than its own weight) to various substrates in air and water were achieved by the combination of weak H-bonds and iron coordination bonds and the synergistic effect of these components. Liu et al [265] synthesized a TOCN/Ti 3 C 2 T X composite film using vacuum-assisted filtering and dispersion of 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO)-oxidized CNF (TOCN). Good mechanical qualities are evident in the generated composite film that mimics the nacre-like lamellar structure of real shells.…”

Low-Temperature Photothermal Therapy Based on Borneol-Containing Polymer-Modified MXene Nanosheets

“…22,23 2D Ti 3 C 2 T x MXene nanosheets (2DM) exhibit strong adsorption and high photothermal conversion efficiency in the NIR region (700−1100 nm), indicating good potential as an effective antibacterial strategy in the postantibiotic era. 24,25 Although previous groups have attempted to treat bacterial infections through PTT by encapsulating or immobilizing 2DM in composite films, 26 hydrogels, 27 and wearable fabrics, 28,29 2DM undergoes rapid aggregation and precipitation in physiological media, which reduces their ability to target bacteria and hinders their clinical application as therapeutic antimicrobials. 30,31 Surface engineering is critical for developing MXenes that disperse well in physiological media and specifically target bacteria.…”

“…In 2011, Naguib et al developed a new family of two-dimensional (2D) transition metal carbides and nitrides, known as MXenes, which have high electrical conductivity, unique optical and mechanical properties, and rich surface functional groups. Consequently, MXenes have diverse applications in energy storage, catalysis, the environment, and biomedicine. , 2D Ti 3 C 2 T x MXene nanosheets (2DM) exhibit strong adsorption and high photothermal conversion efficiency in the NIR region (700–1100 nm), indicating good potential as an effective antibacterial strategy in the post-antibiotic era. , Although previous groups have attempted to treat bacterial infections through PTT by encapsulating or immobilizing 2DM in composite films, hydrogels, and wearable fabrics, , 2DM undergoes rapid aggregation and precipitation in physiological media, which reduces their ability to target bacteria and hinders their clinical application as therapeutic antimicrobials. , Surface engineering is critical for developing MXenes that disperse well in physiological media and specifically target bacteria …”