Amazing tech!
(Lowering the cost of ways "your" stuff can spy on you for its real masters...)

"...without electronics"?? Antennas and switches are electronic devices. Still very clever. But not really a new idea - look up US Embassy bugging by the Soviets with "Infinity Transmitter".

I wonder how small these things can be made. I am thinking about making a biosuit that tracks joint motions in my garage. If I can create a unique sensor pattern for every joint, and make the thing small enough, I can make all the sensors right in my home shop with only the expense of the plastic itself.

Great so since it's not programmable I spam my neighbors' WiFi routers with unrouted IoT messages, not to mention my own!!!??!?

Never mind security.

Pretty darn cool. I agree with Da Schneib though. You could spoof a signal from the IOT to your receiver. A powerful RF spoofed signal acting as a switch (as the video shows) could open all kinds of doors. However, in the right application it might be a perfect solution.

What you want to be sure of is that it's not a quick-n-dirty solution. If you can make each transponder have a unique address then you can have a router for them that you program to only listen for yours. But again, security. Now your neighbor can make money from a manufacturer who gets them to aggregate data from all the houses around them. Further applications left to the observer.

Remember that likely producers of such objects will most likely be the manufacturer of the supply that is being consumed, who will have an interest in your data. If this doesn't make you uncomfortable you haven't thought your way through it yet.

Great so since it's not programmable I spam my neighbors' WiFi routers with unrouted IoT messages, not to mention my own

I don't think it would be that useful. First you'd have to listen in on what your neighbor is 'sending'. Then you have to play that back...but since the signal has no identifier you don't really know what you'd be sending.

You could potentially prank someone - but you wouldn't know what you're pranking them with.

and automatically order more when the bottle is running low

Try to imagine, that this bottle will leak in your bathroom and it will wipe-out your bank account in similar way, like the mobile phone with unlimited credit on roaming. You will return from holiday and find pile of Amazon packages before your home (all delivered automatically with drones indeed).

That would be impossible. Read the article, it explains how the sensor works.

It cannot sense how much the bottle contains, it estimates how much you pour out, if the bottle leaks it will just run dry before the sensor realizes it and you will be stuck without softener.

I have to give them Kudos for ingenuity but I cannot fathom how it would work in real life. Most people are lucky to have Wi-Fi coverage in their entire home with one router. That is with active devices pumping out milliwatts of power. Also, how does a piece of plastic acquire the IP address needed to be accepted by a network when most home routers assign IP addresses on a temporary basis. Just Saying.

In order to transmit a Wi-Fi packet with a unique address there need to be some active logic circuitry involved. This device is just modulating the RF of the existing packets and a receiver is reading the modulated RF. It would be pretty hard to give each unit a unique identity.

The fact is that they could do the same thing with any RF transmitter and receiver. They are just amplitude modulating a RF carrier by changing how much signal is reflected to the receiver. Anywho, I hope the get an A on their term paper.

It is only a matter of years before everyone will be required to have a chip embedded in their body. The government will create mass riots and confusion. People will willingly stand in line for the procedure for "public safety" reasons. After all "Its for the safety of the children!".