On the Reliability of 97% Carbon Content Graphene-based Transmission Lines in Bending Applications and Comparison to Copper and Aluminum Conductors

In our modern world, the use of conformal surfaces to implement various wireless systems is gaining in popularity. Though many flexible substrates are being developed, the conductive materials are fragile and prone to breakage caused by the repetitive bending at a specific spot. Therefore, understanding the bending on the electromagnetic characteristics of different conductive materials is an important area to study. In this paper, the effect of bending on the top copper, aluminum and graphene-based conductors of microstrip transmission lines is studied. A fixture was developed to experimentally observe the bending characteristics of the different aforementioned TLs. The results in this paper showed that on average, after 57 iterations the aluminum connection failed, and after 74 iterations, the copper connection failed. Then, the fixture conducted 750 iterations on the graphene-based conductors and no failure was observed; showing the additional mechanical benefits of the graphene-based conductors. It was also shown that all the materials agreed on S-parameters in full wave simulations. Graphene-based conductive materials showed its superior reliability on bending applications without compromising the performance on the TL.