Next-generation user interfaces will be one of the keys to the emerging wearables markets, to the increasingly connected smart home, and to moving technology and devices further into the mainstream. But launching new types of user interfaces can be tricky, particularly if they’re using new forms of inputs and senses, if they’re for brand new types of devices that don’t have a long history on the market, and if they come from a startup.

Case in point: last week Nest (s goog) decided to halt the sale of its new Protect smart smoke alarm because it found a flaw in the sensor and gesture-based UI. It turns out that the function that enabled users to pause an alarm by waving at it could also be unintentionally triggered by other types of movement. The fear was that if there was a fire and the alarm was going off, a nearby movement…