Influence of Microcracks on Silver/Polydimethylsiloxane-Based Flexible Microstrip Transmission Lines

Daye Ding,Ying Yu,Jiang Liu,Jing Yan,Yuming Fang,Ruozhou Li

doi:10.3390/app11010005

Abstract

Microcrack is commonly seen as a defect in materials that affects the performance of flexible radio frequency (RF) devices. Here, we investigate the influence of microcracks on the RF characteristics of flexible microstrip by stretching flexible microstrip that is based on polydimethylsiloxane (PDMS) substrate and an Ag microparticles/PDMS (AgMP/PDMS) composite conductor. The RF characteristics of the microstrip were monitored with a variety of tensile displacements. An equivalent circuit model of the microstrip with microcracks was proposed to reveal the mechanisms. The fitting results matched the actual measurement well. In addition, the morphology of the microcracks was characterized by SEM and the direct-current (DC) resistance was monitored. The results show that the changes in equivalent circuit element parameters (R, L, C) are due to the change in the conductive pathways, which affect the transmission and reflection of the RF signals.

Highlights

Introduction racks onSilver/Polydimethylsiloxane-Recently, a variety of flexible and wearable electronic devices have appeared on the market
Figure images the fracture composite film, two resistors r1 and r2 the were induced to the equivalent circuit to of reflect the radio frequency (RF) surfaces of the strip conductor of the microstrip
Resistances R1, R2, R3 and R4 were attributed to the finite conductivity of the conductor, which leads the AgMP/PDMS thin film was connected at the bottom of the microcrack

Summary

Introduction

Introduction racks onSilver/Polydimethylsiloxane-Recently, a variety of flexible and wearable electronic devices have appeared on the market. For the development of microwave technology, flexible radio frequency (RF) devices have attracted growing attention due to their flexibility, light weight, low power consumption and good biocompatibility, and have been applied in wireless communication [1,2,3,4,5,6,7], biomedicine [8,9,10,11], sensing [12,13] and military [14] fields. Flexible RF devices are obtained by improving the physical material or structure of traditional. Tremendous work has been performed on flexible materials to realize the flexibility of RF devices. Flexible RF devices are prepared by fabricating a structure made of some metal materials on flexible substrate. Au/Ti was deposited on polyether sulfone (PES) substrate to fabricate a coplanar waveguide for flexible monolithic microwave integrated circuit (MMIC) [1].

Methods

Results

Conclusion