Predictably interfacing biomolecules with solid materials is key for drug delivery, enzyme immobilization, implant biofunctionalization, and biosensor signal transduction. Highly specific interactions controlled by proteins enable explicit recognition of solids and formation of intricate supramolecular architectures in nature. Mimicking natural proteins, GEPIs, Genetically Engineered Peptides for Inorganic solids, have recently become ubiquitous molecular tools in the addressable functionalization of and organizations at solid interfaces. Using these highly versatile biomolecules, one can synthesize solids under biological conditions, use them as molecular erectors in nanotechnology, linkers in probe design, and assemblers in bioelectronics. The principles of molecular biomimetics comprise explicit peptide sequences corresponding to definitive folding patterns via molecular recognition leading to specific chemical or physical functions, the process analogous to MSE where processing leads to microstructures and to materials’ functions. Utility of peptides in MSE is the major factor in translating fundamental bio/solid interface knowledge towards novel genetically engineered future technologies.