Lead zirconate titanate (PZT) arrays for ultrasonic sensing applications in the 2-30-MHz frequency range were fabricated by robocasting, a directed colloidal assembly technique. Both linear and annular arrays were produced by robotically depositing a concentrated PZT gel-based ink to create high-aspect-ratio PZT elements (thickness similar to 130 mum and height similar to1-2 mm) of varying pitch (similar to250-410 mum). The arrays were densified and infiltrated with an epoxy resin to fabricate PZT-polymer composites with 2-2 connectivity. Their dielectric and piezoelectric constants were measured and compared with values obtained for bulk PZT and those predicted theoretically.