Multifunctional Conductive Elastomeric Composites for Broadband Electromagnetic Radiation Shielding and Biomechanical Energy Harvesting
Shovan Biswas, Palash Das, Sayan Chakraborty, Jasomati Nayak, Ajay Haridas, Ankur Katheria, Titash Mondal, S. K. Ray, Narayan Chandra Das
Abstract
The demand for eco-friendly, tactile-integrated, multimodal sensors with self-powered and self-healing capabilities is rising, especially for autonomous sensing systems in smart homes, healthcare, and electronic skin applications. This research introduces multifunctional, self-healing nanocomposites exhibiting remarkable strain sensing, triboelectric nanogenerator (TENG) capabilities, and electromagnetic interference (EMI) shielding. These composites are synthesized by a two-step wet and melt mixing process, integrating zinc oxide cross-linked, 1-(3-aminopropyl) imidazole (API)-grafted carboxylated nitrile butadiene elastomer (XNBR) with multiwalled carbon nanotubes (MWCNTs) to establish a network that is continuous and conductive, resembling nacre. The materials exhibit a self-healing capability of 78.2% at 45 °C while preserving outstanding mechanical strength and elasticity. The composites exhibit an EMI shielding efficacy of −26.4 dB, an open-circuit voltage of ∼224 V, a short-circuit current of ∼24.9 μA, and a power density of 1.1 W/m 2 at a load resistance of 5 MΩ. The material exhibits strain sensitivity with a gauge factor (GF) of 9.78 at elevated strain levels reaching 50%. Furthermore, they incorporate a reversible ionic network that facilitates self-healing properties with autonomous sensing, enhancing smart home, healthcare, and electronic skin technologies. The durability and multifunctionality provide valuable insights for the creation of elastomeric composites that are both high-performance and possess superior mechanical properties, strain sensing capabilities, EMI shielding, self-repair functions, and triboelectric nanogenerators for power portable electronic devices. These versatile and sustainable nanocomposites offer potential for wearable electronics, tactile sensors, and durable environmental solutions.