This paper presents a novel aerogel-based Triboelectric Nanogenerator (TENG) which shows a superior performance for energy harvesting and sensing applications. Polyimide-based aerogel film with varying open-cell content level is developed to be used as the main contact material for the TENG. The fabricated aerogel film is fully characterized to reveal the chemical and mechanical properties of the developed material. It is shown the use of Polyimide aerogel film remarkably enhances the performance of the TENG compared to a TENG with fully dense Polyimide layer with no porosity. This enhancement is due to the increase on the effective surface area, charge generation inside the open-cells of the aerogel, and increase on the relative capacitance of the TENG device. The effect of varying porosity from zero to 70% of open-cell content reveals that the aerogel film with 50% shows the highest performance where the peak open-circuit voltage of 40V and peak short-circuit current of 5 μA are obtained. These values are higher than those of the TENG with simple Polyimide layer with an order of magnitude. Finally, the performance of proposed TENG under resistive loads and capacitors are tested. Thus, this work presents an effective method for high performance TENG.

In this study, the effects of nanoclay on the mechanical properties of poly(methylmethacrylate) (PMMA)/clay nanocomposite foams are investigated. Intercalated PMMA/clay nanocomposites have been prepared through a solvent co-precipitation method. PMMA/clay nanocomposites with only 0.5 wt% of well-dispersed montmorillonite nanoclay showed considerable improvement of mechanical properties; specifically in elastic modulus, tensile strength, and elongation at break. However, with an increased load of clay in the nanocomposite, the mechanical properties decreased due to the agglomeration of excessive nanoclay. Microcellular foams have been processed with PMMA/clay nanocomposite material using a subcritical gas foaming method. When a short foaming time is used, the increased amount of nanoclay induced a greater amount of heterogeneous nucleation during the foaming process and therefore decreased the density of the foam. In contrast, when a longer foaming time is used, foam density increased with a larger nanoclay load due to the higher diffusivity coefficient of CO₂ blowing agent. Nanoclay, as a nucleation agent and reinforcement filler, changed the foaming behavior and mechanical properties of the PMMA microcellular foams. The microcellular foams made of PMMA/clay nanocomposite with 0.5 wt% exhibited an optimized mechanical response under tensile experiments. It is observed that the mechanical properties of nanocomposite foams are greatly related to the mechanical properties of unfoamed material and foam density. The nanoclay dispersion quality is a very important factor for the mechanical properties of both foamed and unfoamed polymer/clay nanocomposites.

Due to their high service temperature, excellent thermal insulation, nanoporous morphology, and low dielectric constant, polyimide (PI) aerogels have the potential capability to be used in the next generation of microelectronic devices and flexible electronics. The main challenge, however, is controlling the shrinkage during the sol–gel process, and developing thin films with improved thermal insulation, reduced shrinkage and density, and controllable thickness while maintaining mechanical flexibility. Yet, the majority of previously reported PI aerogels were in the form of bulk monolithic, with a very limited number of studies on other configurations. In this study, thin film PI aerogels are developed via a doctor blade applicator. Through control of processing parameters, namely solution viscosity, casting speed and inter-blade spacing, thin film PI aerogels with controllable thickness and uniformity are fabricated. The PI aerogel network is formed through imidization of flexible 4,4′-oxydianiline (ODA) and biphenyl-tetracarboxylic acid dianhydride (BPDA) monomers. Replacing 50 mol% of the ODA with a more rigid 2,2′-dimethylbenzidine (DMBZ) in the oligomer backbone gives aerogels with improved strength, enhanced hydrophobicity and lower dielectric constant. 1,3,5-Benzenetricarbonyl trichloride (BTC) is used to create a cross-linked network with strong integrity. Compared to previously used cross-linkers (TAB, OAPS, or TAPP), BTC has a lower cost and is commercially available. Several characterization techniques were performed to examine the physical, chemical, thermal, mechanical, electrical, and optical properties of the fabricated aerogels. These highlighted the multifunctionality of the PI aerogels, combining outstanding mechanical flexibility (fully bendable and rollable), excellent strength (compression E = ∼1.9 MPa), ultralow thermal conductivity (27.5 mW m⁻¹), lightweight (ρ = 0.089 g cm⁻³), superior service temperature (over 560 °C), ultralow dielectric constant (∼2.7), and excellent self-extinguishing behavior. As a potential application of the fabricated thin film PI aerogels, microelectronics packaging can be thus proposed.