I have to admit, the on-screen fingerprint reader on my phone still makes me feel like a sci-fi badass. Probably more so given that I have some idea about the difficulty in implementing it. I’m not sure that it’s actually more practical than the back-side reader, but it certainly feels more awesome.
Wacom type tablet/pen interfaces are a possible precedent for this - there are battery-free implementations of this I think, where the display has a grid of conductors underlying it which communicate with the stylus - not just measuring its position, but querying the state of buttons and the pressure level of the tip - that’s just data coming from an onboard controller in the stylus; it could just as easily be data being read out of onboard storage. Power for the stylus is provided by inductive coupling to the grid under the screen I believe.
I imagine the bandwidth is pretty slim for the extant implementations of this sort of thing though.
And to quote from the linked article, it did support something similar to what the OP describes – though with a battery-powered phone, not a memory card:
Yeah, I mean the transfer of data doesn’t necessarily have to happen through the footprint where the thing is placed (even if the UI implies that’s what is happening) - recognition and pairing might work that way, maybe power coupling, but once that’s all together, data transfer could happen over bluetooth or Wifi or whatever.
There are all sorts of ways it could be made to work. The USB memory stick is something of an accident of history. At least the modern form is. If you were starting from scratch you probably wouldn’t design a memory device like that. You really want a storage appliance, one that contains its own processor and OS and manages access and security internally. Then it could communicate via a whole mess of possible interfaces. Having something that can be wireless powered would be easy as well.
The problem you get relative to the OP’s scenario is how much utility you are willing to give up in exchange for coolness. If the device works when thrown onto a horizontal screen, but can only deliver data at one hundredth the speed that it can if placed in a dedicated cradle, who is going to go with cool? Especially if 100th the speed means an hour to download data instead of less than a minute?
I didn’t specify in the OP, but I was really aiming for “could we do it with a device the size of a MicroSD card (or similar)”. It would be trivial to do with something as gigantic as a thumb/pen/jump drive.
Nowadays the answer is still likely yes. There are some silly capable mixed mode ICs now. Devices the size of a grain of rice doing an entire RF chain with processor.
And of course we are still thinking 1950’s tech. “screen” implies a specific device that produces a display. As we see with some cars’ modern dashboards, there’s no reason for a display to be a simple rectangle in the middle of a plane of otherness. why not make the entire coutner-top/control board a live display? then where you put the device is irrelevant, and the screen contents simply detect its location and flow around it.
As for size - consider there’s a chip in your credit card that’s barely noticeable, maybe the same area as a pencil eraser and thin as paper. the only “size” requirement, is the larger loop of antenna embedded in the periphery of the card, needed to picking up the power to run the chip.