Over the last three decades, the layer-by-layer (LbL) assembly technology has proven to be a simple, cost-effective, reproducible, and highly versatile bottom-up methodology to functionalize surfaces and fabricate robust and conformal multilayered architectures with precisely tailored compositions, structures, properties, and functions at the nanoscale. The simplicity of the LbL technique relies on the sequential deposition of complementary multivalent materials on a substrate into a diverse set of LbL structures. Dating back to the seminal work by Iler on the fabrication of electrostatically driven multilayers of oppositely-charged colloidal particles on flat glass substrates in 1966,¹  the LbL assembly technique only...