(a) Experimental setup of a portable head imaging system with an array of metamaterial loaded 3D antennas around a head phantom (left) and around a human head (right) [45]. (b) A custom 3D printed holder for a metamaterial microwave sensor and small phantom samples for non-invasively measuring blood glucose levels [79]. (c) A standard breast phantom (top) for testing a prototype for microwave breast imaging using a metamaterial-inspired antenna array (bottom) [42].