An extensive search lasting several seconds turned up nothing that precisely matches this, so ...

Food containers for perishable items that have RFID tags that activate only when the packaging is opened.

Example: A carton of UHT milk.

The milk sits on a storage shelf at ambient temperature for a month.

It is then opened (automatically activating the RFID tag), a portion is used, and the package closed and placed in the refrigerator.

The smart* refrigerator "sees" the tag and notes a new container of milk.

If after (for example - user configurable) three days the refrigerator is still "seeing" the milk, it warns "MILK - 3 DAYS" on its display (and reports via WiFi to the user's phone, pc, TV, and via the Internet to Big Brother).

After five days it starts to warn about "MILK GONE BAD".

The most important point is that the system is entirety automatic. The refrigerator does not need to be shown a barcode, or taught an expiry date. Just open the pack, and put it in the fridge; the system does everything else without user intervention.

*for a given value of "smart".
-- 8th of 7, Feb 03 2018

...and the RFID ideas are everywhere! I made a youtube video of RFID pill pack where popping a pill out of a blister pack would modify the traceries of an rfid tag so a reader on the shelf could tell if the medication was being taken regularly and how much. Then I searched and found out somebody had already thought of it.
-- beanangel, Feb 04 2018


RFID tags are static things that have no power source other than impinging EM waves. So, this Idea can only work if there is enough ambient EM energy to allow it to start --and keep running-- some kind of countdown-timer. It can indicate the opened package to contain edible stuff until the countdown reaches zero.
-- Vernon, Feb 04 2018


The countdown timer is in the refrigerator. The refrigerator just "ping"s the passive tag in the container.

[bean] you're probably right, we just couldn't find this exact idea.
-- 8th of 7, Feb 04 2018


People are going to be flooded with messages when things are smart but lazy.
-- wjt, Feb 06 2018


After years of trying, I am at a loss as to how you successfully milk a UHT. Milking an almond was bad enough.
-- RayfordSteele, Feb 06 2018



random, halfbakery