Fig. 2: BC spheroids as 3D building blocks.

a Schematic of potential 2D and 3D structures that can be built from spherical building blocks. b Growth of two example 3D shapes constructed using BC spheroids (see Supplementary Materials for further examples). Model of desired structure (left), the seeded spheroid shape assembled manually (middle) and the resultant material structure produced after 4 days of further growth (right).