Answer: Contact with your lips.
The Lyd bottle is aiming to put an end to spilled drinks altogether thanks to a touch sensor embedded in the lid. Only when this sensor detects the user’s lips on the lid will the bottle’s motorized stopper retreat and allow liquid to flow from the bottle. Additionally there is no designated “sipping spot,” so the liquid can come out of any point on the edge of the lid.
The bottle is powered by a rechargeable battery that should last for two weeks. There is also the option to manually move the stopper should the battery run out. The Lyd comes in two sizes, 13 and 17 ounces, is made of stainless steel and is double-walled and vacuum-insulated. Right now it is still just a Kickstarter campaign.