Batteries may have existed 1000 or more year before Volta: see Wikipedia's History of the Battery. If this was the case, it's hard to see why such a useful technology disappeared for so long. Perhaps it was banned by religious forces claiming it was the work of the devil -- or a scientific threat to religion. More likely there was a huge patent dispute which completely halted the Progress of Science and useful Arts :-)
What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.