Ultrasound has recently been explored as an attractive source of power, especially for deeply seated implantable microdevices. A portion of the externally induced ultrasonic wave is picked up by a small receiver, which energizes the rest of the vital system. While all other components have been advanced and miniaturized, the ultrasonic receiver is still a slab of bulk piezoelectric materials, e.g., dice from PZT (lead zirconate titanate). Such a rectangular or disc shape is not an ideal form factor for wireless power transfer due to many challenges, particularly angular sensitivity with respect to an incoming ultrasonic wave. In this talk, I will discuss our recent work in the first demonstration of omnidirectional ultrasonic powering featuring three-dimensional polyhedral shapes. Based on our 3D printing technique of lead-free piezoelectric barium titanate ceramic, we designed four highly symmetric miniaturized regular polyhedral, known as Platonic solids (i.e., cube, octahedron, dodecahedron), and a sphere. Overall, the proposed ultrasonic powering scheme has the potential to be a transformative solution for many implantable biomedical microdevices.