"Arrive", is broadly defined as the arrival of the first "Universal Assembler" that has the ability to build with single atoms anything one's software defines (like a microwave oven)
Possible creations could include: Doc Martens, Papa John’s, pizza, Pampers’ diapers, and Motorola cell phones
Tom R. Craver, a prominent nanothinkier asserts that nanotecnology will arrive in “full, undeniable” force by 2030