The bill of materials for even the simplest IoT project is likely to include some kind of microcontroller with some kind of wireless module. But could the BOM for a useful IoT thing someday list only a single item? Quite possibly, if these electronics-less 3D-printed IoT devices are any indication.
While you may think that the silicon-free devices described in a paper (PDF link) by University of Washington students [Vikram Iyer] and [Justin Chan] stand no chance of getting online, they’ve actually built an array of useful IoT things, including an Amazon Dash-like button. The key to their system is backscatter, which modulates incident RF waves to encode data for a receiver. Some of the backscatter systems we’ve featured include a soil sensor network using commercial FM broadcasts and hybrid printable sensors using LoRa as the carrier. But both of these require at least some electronics, and consequently some kind of power. [Chan] and [Iyer] used conductive filament to print antennas that can be mechanically switched by rotating gears. Data can be encoded by the speed of the alternating reflection and absorption of the incident WiFi signals, or cams can encode data for buttons and similar widgets.
It’s a surprisingly simple system, and although the devices shown might need some mechanical tune-ups, the proof of concept has a lot of potential. Flowmeters, level sensors, alarm systems — what kind of sensors would you print? Sound off below.
Thanks to [Qes] for the tip.
“It’s a surprisingly simple system, and although the devices shown might need some mechanical tune-ups, the proof of concept has a lot of potential.”
Turning the human eardrum into a kind of bug.
Yeah, why not print some kind of noisemaker? I bet a microphone on my PC could hear my air conditioner running outside and put it “online”.
Brings the TV remote controller full circle. The early ‘clicker’ actually clicked and produced an ultrasonic(?) Noise mechanically, which the TV listened for to change channels. 4 frequencies allowed for channel up/down and volume up/down
It’d make for some interesting quarter-wave dipole earrings.
I’m just guessing, but I bet picking up such low, low levels, on top of a, say, Wifi network that’s deliberately transmitting at as many signal levels as the network can separately discern, would make this technique a massive pain in the arse.
Wouldn’t these signals end up beneath the noise floor, because if they were noticable above the actual Wifi, the local network would increase strength and put them beneath the noise floor?
Maybe it’s more practical for less intelligently-managed frequencies, like FM broadcast. Still sounds like a massive pain though. Does it work outside of a Faraday cage?
While interesting, I think a better system would use an amorphous solar cell to turn ambient light and into it’s power source. Seriously, indoor lighting can provide plenty of power with the right solar cell.
More importantly, plenty of useful devices could be designed to run on that limited power, as evidenced by common calculators.
You mean these calculators?
https://youtu.be/uLTDuGhqE2w
Immediately thought of this:
https://en.wikipedia.org/wiki/The_Thing_(listening_device)
Oh crap. I have to deal with management consultants daily, this is a great idea but calling it printed wifi will further fuel their bollocksy verbal diahorrea.
Also this is producing damp waves no? Not great for interference? Maybe i got that wrong