MEMS Array Chip Can Project Video the Size of a Grain of Sand

15 hours ago (spectrum.ieee.org)

This reminds me of the original patents that Magic Leap had, which involved pumping light through a single optical fiber that was wiggled by piezoelectrics into a spiral to project light (https://kguttag.com/2018/01/06/magic-leap-fiber-scanning-dis...).

  • Seems what it is, but with a "waveguide" instead of an "optical fiber" wiggling about. Seems like a sneaky use of the word "projection" though, since the "surface" the image is "projected" is just what the flopping waveguide head traces, with no projection extending beyond the end of the waveguide.

    • Yes but one could argue the frame refresh/redraw cycle of a laser projector or lcd projector is the same at slow speed. It’s not just one giant ball of light. It goes through a process and the frame itself has to redraw.

I wonder if this has implications for custom home chips/prototyping. I'm sure a big issue is vibrations but something like this could remove the need for masks at least. (again, not my area so I am clobbering terminology I am sure). It may open up home fab capabilities.

  • In general, hobby photo-lithography projects already use DMD/DLP projectors, and some inexpensive optics.

    Huygens Optics:

    https://www.youtube.com/watch?v=_w0Z2Y5vaAQ

    Sam Zeloof:

    https://www.youtube.com/watch?v=Nxz_ENnmgtI

    In general, getting vanity silicon made is usually much less expensive than trying to bootstrap a fab line. =3

    • I think half the fun for people that do things like this is figuring out how to out innovate a multi-billion dollar company so that they can make something 1/4th as good but at 1/10000th the price. I bet there are some -really- innovative people out there that would figure alternatives to a lot of the expensive parts of the process and figure out how to be able to produce 2000's level chips at home. I'm not one of them though :)

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  • I think abusing a write-off electron microscope to side step the need for masks is also an interesting idea, however, I believe acquiring wafers of sufficient quality and depositing layers to be etched could be the bigger challenge here.

Seems like you could put a few of these on a contact lens and minimally get a small private HUD. Seems like with a few of them (or fast enough scanning speed) you could build effectively a light field to give it depth)

> The chip projected a roughly 125-micrometer image of the Mona Lisa.

This may seem small (barely visible as a dot to the naked eye), but that's also the geometric mean of the Planck length and the diameter of the observable universe. So average size actually.

  • I really can't follow your comment and I've been trying. Would you mind a longer explanation of what you're getting at here?

    • They mean 125um = sqrt(a*b), where a is the Planck length* and b the size of the observable universe (I didn't verify). Implying, 125um is some sort of middle ground. *Often said to be the smallest length with physical meaning.

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Cool. Now I can show videos to my fruit flies! /s

Srsly title should be "MEMS Array Chip the Size of a Grain of Sand Can Project Video"

not

"MEMS Array Chip Can Project Video the Size of a Grain of Sand"

  • It is actually about a 0.125mm projection, not the size of the chip. But more about steering lasers, which is really what they wanted to do.