Electromagnetic Functions Modulation of Recycled By-Products by Heterodimensional Structure

Abstract

One of the significant technological challenges in safeguarding electronic devices pertains to the modulation of electromagnetic (EM) wave jamming and the recycling of defensive shields. The synergistic effect of heterodimensional materials can effectively enable the manipulation of EM waves by altering the nanostructure. Here we propose a novel approach for upcycling by-products of silver nanowires that can fabricate shape-tunable aerogels which enable the modulation of its interaction with microwaves by heterodimensional structure of by-products. By-product heterodimensionality was used to design EM-wave-jamming-dissipation structures and therefore two typical tunable aerogel forms were studied. The first tunable form was aerogel film, which shielded EM interference (EMI shielding effectiveness (EMI SE) > 89 dB) and the second tunable form was foam, which performed dual EM functions (SE > 30 dB & reflective loss (RL) < -35 dB, effective absorption bandwidth (EAB) > 6.7 GHz). We show that secondary recycled aerogels retain nearly all of their EM protection properties, making this type of closed-loop cycle an appealing option. Our findings pave the way for the development of adaptive EM functions with nanoscale regulation in a green and closed-loop cycle, and they shed light on the fundamental understanding of microwave interactions with heterodimensional structures.

1. Introduction

With the continuous scaling of complementary metal–oxide–semiconductor (CMOS) technology, three-dimensional (3D) integration has emerged as a practical solution to enhance device density by vertically stacking devices or dies, keeping pace with Moore’s law [1, 2]. However, this stacking approach significantly exacerbates electromagnetic interference (EMI), which poses a critical challenge to the reliability and stability of integrated circuits [3–5]. Beyond compromising circuit performance, the increasing intensity of EMI generated by high-density integrated systems can also extend its impact to human health and the surrounding environment, if no shielding is provided [6–9]. Presently, nanomaterial-based EM-functional shrouds are appealing due to their ultrahigh conductivity, flexibility, and varied dimensions [10]. Yet, how to deal with themselves and their by-products, however, is challenging because those are probably nanotoxic (including carcinogenicity and reproductive toxicity) and degradation-resistant [11–14]. In addition, the growing environmental impacts associated with electronic waste make sustainable development in next-generation consumer electronics essential [15, 16].

Low-dimensional nanomaterials for EM function contain different dimensions (zero-dimensional (0D), quasi-one-dimensional (Q1D), one-dimensional (1D), and two-dimensional (2D) nanofillers) [17–19]. The ingenious combination of these different dimensions known as heterodimensional structures will exhibit novel physical properties (containing nanostructure, conductive network distribution, EM response, etc.) beyond those of the parent material at the nano/micro/macroscale [20]. The modulation of heterodimensional structure can effectively realize super effective EMI shielding or better microwave absorption (MA) and, to some extent, enables the integration of EM dual functions, specifically EMI shielding and MA [17, 21, 22]. For instance, the synthesis of 1D metal nanowires (MNWs)/carbon nanotubes (CNTs) and 2D graphene/MXene boosts the reflective dissipation and enhances the flexibility of the whole system [23–26]. Likewise, the combination of 0D nanomagnet and 1D/2D nanoconductor in a single composite can synchronously achieve the “cond