Flexible inkjet-printed graphene antenna on Kapton

Abstract

Flexible printed antennas have attracted a great deal of attention due to their significant potential for different technologies. Using novel materials such as graphene and inkjet printing fabrication techniques is key for further developing this technology. Several studies have characterised them separately, but it is still challenging to merge them to produce plausible flexible antennas. This paper presents the whole methodology, covering the design, fabrication process, and characterisation of a flexible, inkjet-printed graphene-based antenna intended to use within flexible electronics. The antenna pattern follows a new optimised quasi-Yagi–Uda design working in the desired range of operational frequencies (5–6 GHz). It consists of four directors and a pair of reflectors to improve the directivity with an efficiency of 42%. A co-planar waveguide feeding method is designed to tune the impedance matching, ensuring the wearer’s comfort. The flexible Kapton film was treated with plasma to improve the ink’s adhesion and coverage. The novel antenna suggested potential in advanced materials devices, suitable for various wireless applications for next-generation conformal and flexible electronic devices and applications.

A monopole antenna with cotton fabric material for wearable applications

“…On the other hand, in antenna design choosing flexible materials have to be considered to be utilized close to the rounded parts of the human body. Several kinds of wearable antennas based on flexible materials are studied and investigated by researchers such as textile 9 , flexible substrate 10 , dielectric resonators 11 , polyimide 12 , polydimethylsiloxane 13 , paper 14 , and Kapton 15 . Among these materials, textiles are preferred due to their lightweight and high flexibility in integration with clothing 16 .…”

Highly-dependable printed neuromorphic circuits based on additive manufacturing

“…The rapidly advancing domains, such as Internet of Things (IoT) [1], wearable devices [2], and smart packaging [3], have resulted in a heightened requirement for flexible, bio-compatible, and low-cost electronics. In this context, printed electronics (PE) becomes a promising solution, as PE allows the manufacturing of flexible and stretchable circuitry, with possibly non-toxic materials through a spectrum of material [4,5] and substrate [6,7] options. Additionally, due to the additive manufacturing process, printed devices can be fabricated in a low cost.…”

Design and test of an inkjet-printed microwave interdigital capacitor on flexible Kapton substrate

“…Recently, growing attention has been paid to inkjet printing (IJP) technology for electronics applications. The prominent factors that are playing a major role in raising the research interest in this technology include cost efficiency, fast prototyping, better optimization in largescale production, and rapid testing of the products [1]. Moreover, such technology represents an environmentally friendly alternative to the more conventional printed circuit board (PCB) fabrication processes; the pattern is directly printed onto substrates without employing screens or masks, thus generating nearly zero waste [1].…”

“…They can be placed in contact with the human skin or integrated into clothes for different applications aimed at health care, sports, biomonitoring, and human-machine interaction [8,9]. In such a context, several microwave devices have been proposed [9], such as flexible antennas [1], gas sensors [10], humidity and temperature sensors [11], and even more complex microwave systems have been developed for energyharvesting [12], smart skin [13], and telecommunication applications [14].…”