I think calling a device with dimensions on the order of a millimetre 'dust-sized' is a bit of a stretch. While dust particles might adhere together to form structures at the millimetre scale, a google search for 'dust size' confirms that dust particles are generally at the micron or sub-micron scale. That's a fairly substantial difference.
Rice is not "dust" and sand is not "dust" by any stretch of parlance.
These things will fall on the ground and you'll hear them hit the floor in a quiet room.
These things will not float on windless air, suspended in a sunbeam.
They are not saw dust, either. They are not iron filings. They are not crushed slivers of glass. They are something more.
Look at the picture. Maybe relative to other implantable electronics, they are certainly very small. But qualitatively speaking, not soot, not smoke, not powder, not dust.
While I'm excited by the impact on the health industry (among other things), I wonder how this will affect spying (whether it is government or otherwise). Then again, I am just paranoid.
Since you have to feed it ultrasonic energy to power it, I suspect it is not too bad because, IIRC, ultrasonic has a short range.
You could feed it electromagnetic energy - but then all you really have is a smaller version of the Great Seal bug https://en.wikipedia.org/wiki/The_Thing_(listening_device). I wouldn't be surprised if those already exist in about this size and the paper linked to from the web page talks about several such devices (and how they are not as well suited for implantation).
Haha, yeah, you know when you're in a plane just before take-off and the attendants walk up and down the aisles with (presumably) insecticide bombs spewing mist... :/
From reading (ok, skimming) the paper, it seems that the sensor is powered by an external ultrasonic transducer and, I think, returns data by modulating that signal (a bit like RFID).
That means that you lose power when the ultrasonic is removed.
It seems that you could do a lot more with it if you added a battery and some memory so that it can record signals when the ultrasonic is not present? I am thinking of things like the Michigan Mote which was also about a cubic millimetre. http://www.eecs.umich.edu/eecs/about/articles/2015/Worlds-Sm...
I see them using not one but 2 myo sensors on the arm at 1:08 which is amazing because those act like an implant but theyre very inaccurate and even then theyre getting ok movement for the fingers etc.
I made an arm which moves in a a similar way but i didnt make fingers which is the hardest part actually. Human fingers are an amazing boon from nature to us. Theyre incredibly accurate and sensitive tools with so many sensors on them which is what makes them so hard to replicate.
