Biodegradable, Flexible Transparent Ordered Ag NWs Micromesh Conductor for Electrical Heater and Electromagnetic Interference Shielding Applications

Abstract

Flexible transparent and biodegradable conductors with excellent performance are quite desirable for the development of portable electrical heaters and electromagnetic interference (EMI) shielding. As a promising candidate, electrical homogeneity and stability are required for a silver nanowire (Ag NW) network conductor to increase its reliability and robustness. Herein, an optimally well organized silver nanowire micromesh (Ag NMs) electrode embedded in biodegradable poly(Llactic acid) (Ag NMs/ePLLA) is prepared without a template by virtue of the coffee-ring effect. The Ag NMs/ePLLA electrode possesses a low sheet resistance variation (<5%), leading to a highly homogeneous temperature distribution and a rapid response time of 6 s with a saturation temperature of 111.8 °C at a low driving voltage of 3 V. Moreover, the Ag NMs/ePLLA film also shows an outstanding EMI shielding efficiency of ∼27.6 dB in X-band with a sheet resistance of ∼10 Ω/sq to prevent electromagnetic radiation pollution and excellent biodegradable properties to avoid pollution by electronic waste. Therefore, the multifunctional portable Ag NMs/ePLLA electrode provides great opportunities in the application fields of thermal management and EMI shielding.

Wearable, Biodegradable, and Antibacterial Multifunctional Ti3C2Tx MXene/Cellulose Paper for Electromagnetic Interference Shielding and Passive and Active Dual-Thermal Management

“…Moreover, Ti 3 C 2 T x /CNF papers possess superior EMI shielding performance due to their outstanding electrical conductivity, which exhibit an EMI SE of >30 dB across the entire X-band (Figure 3c, Figure S2a) with different Ti 3 C 2 T x contents from 5 to 25 mg and satisfy the commercial EMI shielding application demand. 32 To eliminate the Ti 3 C 2 T x / CNF paper thickness (t) effect, EMI SE/t is usually adopted to evaluate the EMI shielding performance. As a representative example, the Ti 3 C 2 T x /CNF paper (∼0.6 Ω/sq, ∼41 μm thick, 20 mg MXene) with an SE of ∼48.5 dB exhibits mean EMI SE/t of ∼12,100 dB•cm −1 and maintains a stable shielding performance even after 10,000 bending cycles (r ∼ 2 mm, Figure 3d), demonstrating extra-thin thickness, flexibility, and reliability properties in a single functional film.…”

“…This flexible Ti 3 C 2 T x /CNF paper keeps stable electrical conductivity throughout the bending process ( r , ∼2 mm, Figure b and Movie S1). Moreover, Ti 3 C 2 T x /CNF papers possess superior EMI shielding performance due to their outstanding electrical conductivity, which exhibit an EMI SE of >30 dB across the entire X-band (Figure c, Figure S2a) with different Ti 3 C 2 T x contents from 5 to 25 mg and satisfy the commercial EMI shielding application demand . To eliminate the Ti 3 C 2 T x /CNF paper thickness ( t ) effect, EMI SE/ t is usually adopted to evaluate the EMI shielding performance.…”

Universal assembly of ordered Ag nanowire micromesh conductors on arbitrary substrates by manipulating the contact angle

“…Silver nanowire (Ag NW) conductors have garnered increasing attention in wearable optoelectronic devices, such as electrical heaters, neuromorphic memristors, solar cells and organic light-emitting diodes, owing to their robust bending durability, high light transmission, and high conductivity. [1][2][3][4][5][6][7][8][9][10] However, the poor electrical homogeneity and thermal stability of Ag NW conductors largely overshadow their wide applications due to the random or uncontrolled patterns of Ag NW networks, where the random distribution of Ag NWs might constitute local hotspots responsible for the early degradation of electronics. 8,11,12 These inferior behavior would be magnied with increased scaling of the Ag NW-based devices because of the rheological solvent, 7,13 where an ordered assembly structure for Ag NWs is desired to tackle these difficulties.…”

“…20,21 Recently, we developed a facile spray-assisted self-assembly method for innovative Ag NW micromesh (Ag NM) conductor fabrication in virtue of the coffee-ring effect. 8,10,11,22 The resultant Ag NM electrodes with abundant microscale open areas and explicit conducting paths exhibit excellent optoelectronic properties with small amount of Ag NWs, high thermal stability, and low sheet resistance variation (<8%), which is better than those of commercial exible transparent ITO electrodes. 8,11 Nevertheless, several momentous unsolved questions in this advanced strategy severely limit the wide application of Ag NM conductors: (1) the Ag NMs are only obtained on several particular at substrates with the volatile isopropanol (IPA) solvent; (2) the Ag NM structure cannot be achieved on any substrate with safer aqueous solvent; (3) the boundary condition for Ag NM formation is still indistinct; (4) most importantly, there is no universal strategy that can make Ag NMs on arbitrary substrates with aqueous and volatile organic solvents, including IPA, ethanol and methanol, for different specic applications.…”

Stretchable, Adhesive, and Bioinspired Visual Electronic Skin with Strain/Temperature/Pressure Multimodal Non-Interference Sensing

“…To adapt to the natural environment, animals such as chameleon and octopus have gradually developed a unique function of skin color change after nature evolution. The thermochromic devices have been exploited to visualize the temperature stimulus with a color change for application in sensors , and displays, − which can be considered an effective solution to overcome the limitation of relying only on terminals with complicatedly physical connections and immensely enhance information interaction in the fields of military equipment, security systems, and human–machine interaction. In this work, inspired by the reversible color-change property of chameleon skin, a bioinspired stretchable and adhesive multimodal chromotropic e-skin system (MCES) consisting of adhesive polydimethylsiloxane (a-PDMS), conformal liquid metal (LM), thermochromic inks, and bare PDMS encapsulation layer was proposed (Figure ), which was capable of simultaneously detecting and distinguishing multi-stimuli of pressure, temperature, and strain through triboelectric, thermochromic, and capacitive effects with disparate perceptive signals.…”