Flexibly stretchable acrylic resin elastomer films for efficient electromagnetic shielding and photothermal conversion

Abstract

A retractable, stretchable shielding device with large areal strain variability is essential for intelligent wearable electronics. Most developed shielding composites are films or foams without ductility and restorability. Furthermore, the electronics applied in a frigidly harsh environment require thermal collection and heat dissipation. Herein, we combined a dielectric elastomer (ADE) with single-walled carbon nanotubes (SWCNTs) to obtain composite films with mechanical stability, which exhibit biaxial stretchability, remarkable electromagnetic interference (EMI) shielding property, photothermal conversion and rapid cooling ability. Through an efficient spray process, the SWCNTs form a uniform conductive network above the ADE matrix, providing stabilized and real-time tunable shielding effectiveness (SE) up to 32 dB in the X-band with an areal strain of 100%. In comparison, the SE of 300% areal strain can reach about 30 dB. In addition, the as-prepared SWCNTs/ADE films possess high resistance to bending. After 1000 bending times, SE retains 47% of its original value, showing a specific fatigue resistance. SWCNTs/ADE films also combine high heat-collection characteristics. After being exposed under a 150 W infrared bulb for 180 s, these films self-heat to 66.5 °C and cool down to room temperature (RT) within 10 s. Moreover, the photothermal feature can remain stable after 200 cycles, while having a rapid-responsive ability. This work reveals the potential of composite elastomers as a candidate for self-heating shielding devices applied in wearable electronics at icy temperatures.