Experimental studies of the robustness of the conductive-mesh-polymer composite towards the development of conformal and transparent antennas

Abstract

One of the key challenges of the development of flexible and optically transparent antennas and sensors is the limited availability of the suitable materials. The traditional transparent conductors suffer from the drawback of instability in repeated bending and twisting and, thus, are not appropriate candidates for flexible transparent antenna development. Integration of flexible conductors with flexible substrates is another challenge not only for the realization of flexible transparent antennas but also for other types of flexible antennas, radio-frequency (RF) devices and sensors. Apart from the traditional flexible conductive and substrate materials, Conductive-Mesh-Polymer composite can be an efficient alternative for the realization of flexible transparent antennas. The polymer proposed here is Polydimethylsiloxane (PDMS), which is a flexible transparent substrate and the proposed transparent conductor is mesh-structured flexible conductive textile, VeilShield from Less EMF Inc. USA. Uncured PDMS is a sticky liquid and after curing, it makes a strong attachment with VeilShield. Due to the mesh-structured configuration of this conductor, uncured PDMS penetrates through the gaps among the threads and after curing of the PDMS, a composite is formed that has high optical transparency, flexibility and robustness against repeated mechanical deformations. For these attractive features, this composite material is a good candidate for the realization of optically transparent antennas, sensors and RF devices. In this paper, the feasibility of the VeilShield-PDMS composite towards the realization of flexible, robust and transparent antennas is assessed by investigating the morphology of the composite and exploring the RF performance of a microstrip patch antenna, fabricated using this composite, through 50 times bending cycle. The investigated results demonstrate the suitability of the VeilShield-PDMS composite towards the realization of flexible transparent antennas as well as other electronic components that are frequently exposed to repeated physical deformations.