I wonder what sort of sensor you would need to detect a spiked drink. I bet the cup is just guessing at sugar / vitamin levels with a cheap PH sensor (that’s just a guess.) I can’t imagine that you’d be able to detect knock out drugs with out some serious molecular analysis. PH sensors are cheap, and available, and there’s already plenty of people playing with them on arduinos. I can’t imagine the cup has anything more sophisticated than capacitive , optical, PH, and magnetic sensors.
Here is a group of arduino folk who speculated on the possibility of finding lead electronically via Arduino: http://forum.arduino.cc/index.php/topic,208457.0.html
Their assessment was that it was not possible. The page for the cup is very low on technical details, and the cup itself appears to be very small. If I were tasked with making such a thing, I would try to guess soda brands, and juice types by color and PH. I bet that there are subtle and detectable differences brand to brand that will make that possible. I am sort of skeptical that this cup does any significant molecular analysis of the drink, simply because I cannot find a device that does anything remotely like that, that would fit inside a cup.
Check out this quick bio-analysis tool: http://www.urimicrofluidics.com/index.php/research/60 - this is supposed to be very small. Not fitting in a cup, though. We’re talking shoe box sized at least.
Then again, he claims the ability to be able to detect how much protein is in a protein shake. I can’t imagine how you’d do that. Then again I’m not a chemist at all.
Maybe just weld a cup on to a gas spectrometer?
There are these things: http://store.drinksafetech.com/categories/ - which probobly work by some pre-coated chemical reaction. You could rig up some sort of cartridge with thousands of tiny tester patches that are exposed to the liquid, and an optical sensor tells if the color change occurred. I can’t see that being a massive advantage over the testing strips, which work on any cup so that you don’t have to be a cup carrying weirdo.
I have no idea of those strips are at all effective, by the way.
I poked around for electrical methods of detecting ketamine - a common knock out drug used by predators. Seems like the most common thing is mass spectrometry, which uses desktop sized device.
I’m not a chemist. I’d love to be proven wrong. Right now: highly skeptical of the vessyl.