Brandeis University biophysicist and erstwhile inventor Daniel Perlman has created a brilliantly conceived drip-free Wine Bottle. After studying the flow of liquid over the course of three years and watching what happens when wine is poured to discover the source of the drip, Perlman determined that a 2mm groove at the top of the neck would stop the dripping completely, even if the bottle is full or near-full.
He…saw that a stream of wine tends to curl backward over the lip and run down the side of the glass bottle because glass is hydrophilic… Using a diamond-studded tool, Perlman, assisted by engineer Greg Widberg, created a circular groove around the neck of the bottle just beneath the top. A droplet of wine that would otherwise run down the side of the bottle encounters the groove, but can’t traverse it. Instead, it immediately falls off the bottle into the glass along with the rest of the wine.
photo via Brandeis University