A filter made of layers of aluminum nitride is 100 times smaller than the ceramic filter used in cell phones. It blocks unwanted signals from interfering with the receiver. The inductor, which determines the proper frequency, also shrinks to a micron-sized wire loop. Bundling microcomponents also resolves the problem of sufficient power. Larger prototypes required bit batteries, yet couldn't operate for years like a watch.
Clarity is another concern.
Most phones strain to understand voice-based instructions and conversation crackles. But Gammel's microcomponents sound impressively clear. They react very strongly to video. Seeing the person you're talking to enhances the human experience. Not everyone agrees the device would sell, even if it works.