A Novel Approach to Integrating 3D/4D Printing and Stretchable Conductive Adhesive Technologies for High Frequency Packaging Applications

This paper demonstrates a new method for the free standing 3D printing of a polyurethane (PU)-based electrically conductive adhesive (ECA). Due to the special mechanical and electrical properties of the in-house-made ECAs [1, 2], which has an ultralow resistivity of approximate to 1.0 x 10(-5) Omega cm, our approach opens new avenues for creating soft electronics applications, such as strain sensors [3], soft robotics [4, 5] and flexible, wearable RF devices [6]. A proof-of-concept fractal 3D Hilbert dipole antenna at 433 MHz ISM band is designed and fabricated by this method.