Determination of optimum placement of the liquid metal antenna design embedded in concrete beam prototype under center — Point loading test

This study describes the application of dipole liquid metal antenna as a possible sensor of crack when embedded in a concrete beam prototype on several locations. The approach to the fabrication of antenna is based on McGyver-esque approach to microfabrication. The antenna consists of Eutectic Gallium Indium (EGaIn), a fluid metal alloy injected into microfluidic channels comprising a silicone elastomer composed of polydimethylsiloxane (PDMS). While the fluidic dipole antennas are highly flexible, stretchable, and reversibly deformable, changing its length through stretching the elastomeric channel also changes its resonant frequency. Experiments show that increasing the length of the antenna (not embedded in concrete), decreases its resonant frequency. This relationship becomes the basis of the study whether the antenna behaves in the same manner when it is already embedded in prototype concrete beams. Simultaneous testing using center-point loading machine and network analyzer for the three embedding locations of antenna are conducted to gather the necessary data that would best adapt to the inverse relationship of antenna´s resonant frequency and displacement due to loading.