Percolated Network of Mixed Nanoparticles with Different Sizes in Polymer Nanocomposites: A Coarse-Grained Molecular Dynamics Simulation

Advances in Monte Carlo Method for Simulating the Electrical Percolation Behavior of Conductive Polymer Composites with a Carbon-Based Filling

Conductive polymer composites (CPCs) filled with carbon-based materials are widely used in the fields of antistatic, electromagnetic interference shielding, and wearable electronic devices. The conductivity of CPCs with a carbon-based filling is reflected by their electrical percolation behavior and is the focus of research in this field. Compared to experimental methods, Monte Carlo simulations can predict the conductivity and analyze the factors affecting the conductivity from a microscopic perspective, which greatly reduces the number of experiments and provides a basis for structural design of conductive polymers. This review focuses on Monte Carlo models of CPCs with a carbon-based filling. First, the theoretical basis of the model's construction is introduced, and a Monte Carlo simulation of the electrical percolation behaviors of spherical-, rod-, disk-, and hybridfilled polymers and the analysis of the factors influencing the electrical percolation behavior from a microscopic point of view are summarized. In addition, the paper summarizes the progress of polymer piezoresistive models and polymer foaming structure models that are more relevant to practical applications; finally, we discuss the shortcomings and future research trends of existing Monte Carlo models of CPCs with carbon-based fillings.

Photothermal Lithography for Realizing a Stretchable Multilayer Electronic Circuit Using a Laser

Photolithography is a well-established fabrication method for realizing multilayer electronic circuits. However, it is challenging to adopt photolithography to fabricate intrinsically stretchable multilayer electronic circuits fully composed of an elastomeric matrix, due to the opacity of thick stretchable nanocomposite conductors. Here, we present photothermal lithography that can pattern elastomeric conductors and via holes using pulsed lasers. The photothermal-patterned stretchable nanocomposite conductor exhibits 3 times higher conductivity (5940 S cm-1) and 5 orders of magnitude lower resistance change (R/R0 = 40) under a 30% strained 5000th cyclic stretch, compared to those of a screen-printed conductor, based on the percolation network formed by spatial heating of the laser. In addition, a 50 μm sized stretchable via holes can be patterned on the passivation without material ablation and electrical degradation of the bottom conductor. By repeatedly patterning the conductor and via holes, highly conductive and durable multilayer circuits can be stacked with layer-by-layer material integration. Finally, a stretchable wireless pressure sensor and passive matrix LED array are demonstrated, thus showing the potential for a stretchable multilayer electronic circuit with durability, high density, and multifunctionality.