He became a lecturer at Kyushu University in 1972. From 1972 to 1974, he was a postdoctoral fellow at the University of California, Santa Barbara. He joined Kyushu University in 1975 and became a full professor there in 1988.
Shinkai is known for his pioneering research in molecular self-assembly. Molecular self-assembly is the assembly of molecules without guidance or management from an outside source.
His main field of expertise and research interests are Host Guest Chemistry, Molecular Recognition, Liquid Crystals/Organic Gelators Sugar Sensing/Sugar-Based Combinatorial Chemistry, Polysaccharide-Polynucleotide Interactions, Sol-Gel Transcription and Inorganic Combinatorial Chemistry.
He was the winner of the Izatt-Christensen International Award in 1998. The Award was initiated by Reed McNeil Izatt, recognizing excellence in macrocyclic chemistry.