While there's no way to confirm how many major inventions were made with sex in mind, we do know of many technologies whose first (or a close second) use was sexual. Sex historian and author Hallie Lieberman said when it comes to replicating sex, humans are quite innovative.
"Anytime you have a new material, there [are] sexual uses for it," Lieberman explained. "Aluminum, for example. [In] the archives of the Smithsonian, aluminum is this new material coming out for all these things, and one of the things was a casing for a vibrator. Similarly, materials and small motors in the early 1900s were used for vacuums. And then they're like, 'Oh, we can use them for vibrators.'"
It should feel good and be safe
There's obviously a wide application for small, quiet motors and many items that require them, but their use in vibrators probably expedited their evolution. However, the technology doesn't just have to be good to catch on. As Lieberman explained, it has to feel good, too.