Sustainable Broadband Monopole Antennas Based on Recyclable Liquid Metals and Biodegradable 3D-Printed Dielectrics

This paper presents the first 3D-printable antenna with fully recyclable and re-usable metals, for sustainable RF communication applications. The proposed antenna consists of a fully 3D-printed substrate made from biodegradable polylactic acid (PLA). It features an asymmetric monopole that provides a maximum measured broadband operation range from 1.8 GHz to 3.2 GHz and is fed by a coplanar waveguide (CPW) structure. The conductive components (i.e., the radiator, feed line, and ground plane) are fabricated using liquid metal. A repeatable method for filling the channels with liquid metal is developed, allowing the conductive components to be fully recycled and refilled. The effectiveness of the recycling process is verified by consistent measurement results, the difference of bandwidth between which is less than 3%.