Technological savvy is an essential requirement for enabling a mixed signal SoC as well as a Mechatronics structure.
Analog Pad buffers, DC-DC converters or level-shifters are considered as part of Cell Libraries because they end-up within the active silicon region of a SoC, while MEMS (Micro Electro Mechanical Structures) and Parametric Test Structures end-up outside of it, respectively in the mechanical region and in the scribe lines dividing the wafers into dies.
Cell Libraries are driven by a slew of design criteria and benchmarks, while the major issues for Microstructures are simulation refinement and yield management.