There is no shortage of researchers aiming to make  ingestible smart sensors , designed to keep tabs on what’s happening in your guts, and sending this information to a paired mobile device. But a  new device , created by engineers at the University of Wisconsin-Madison, does more than passively observe your internal goings-on. Instead, it actually prompts overweight individuals to lose weight by attaching to the outside of the stomach and then dampening down feelings of hunger on the part of the “wearer.”