Opinions expressed by Entrepreneur contributors are their own. Amazon Fire Phone, Google Glass, New Coke and Nintendo’s Virtual Boy: What do all these products have in common? They didn’t sell.

I put a memory card in the camera and it just...disappeared. Reviewing camera prototypes is never boring ...

How do you close the gap between I wonder and I know? You make a prototype. A prototype is a tool that gives you a chance to investigate your ideas and explore what could, should, or would come next, ...

At the PARI Hypersonics Advanced Manufacturing Technology Center (HAMTC), from left: Nate Humbert, lead additive manufacturing engineer, GE Additive; Will DeVerter, aeronautics and astronautics ...

This video captures several prototype and performance cars testing on the Nürburgring track, where manufacturers evaluate vehicles under demanding conditions. Among the cars seen on the circuit are ...

Donut Lab battery validation adds a 10-day room-temperature retention figure of 97.7%, while energy density and weight data remain absent.