Turning Soap Film Into a Projector Screen

An anonymous reader writes "3 graduate students from University of Tokyo, Carnegie Mellon University, and the University of Tsukuba have developed a colloidal display — a clear projector screen that can control its transparency. Normally soap film will allow light to pass through, but the colloidal display does not. It mixes colloid into the solution and uses ultra sonic speakers to vibrate the surface of the soap film to achieve this. They have created several prototypes, such as 3D planar screen, to show how this technology can be useful."

Comments

early post

[Anonymous Coward]

is this the first post?

Here's a video showing the display in operation and how it works. Pretty neat...

Gravity

[Hentes]

The problem with soap films is that fluid from their top is slowly flowing to their bottom, causing their top to become thin. As a result, the film bursts in a few minutes. I haven't seen anything on how they plan to make these displays durable.

Re:Gravity

[llamapater]

spin it with a slight shake maybe to geek the center thick? or use the frequencies they're using to mix it to evenly distribute it.

Re:Gravity

[Doc Ruby]

The bottom of the film could drain into a line that's pumped back to the top of the film. The device would maintain only the top and bottom edges, while the film would form between them. Since they're projecting ultrasound across the film's surface I expect they could run the hydraulics and ultrasonics there, too.

Re:not very practical currently, but pretty cool.

[jhoegl]

It may lead to better things however. For those inventors out there that want to bring true 3D to everyone by projecting it onto a 2D plane, they now have a different line of thinking to take.
Now they can think about 3d encapsulation objects to bring out true 3d.

Colloid

[techno-vampire]

TFS says, in part, "It mixes colloid into the solution..." This is Just Plain Wrong because there is no such thing as "colloid." A colloid is a substance microscopically dispersed evenly throughout another substance. I haven't RTFA (This is Slashdot, after all!) but I'd be willing to bet that TFA says that they add something to the solution to make it into a colloid and that the submitter (and editor) didn't bother to make sure they got it right.

Re:Colloid

[Doc Ruby]

You evidently didn't even really read TFWA you quoted, either:

A colloid is a substance microscopically dispersed evenly throughout another substance.[1]

A colloidal system consists of two separate phases: a dispersed phase (or internal phase) and a continuous phase (or dispersion medium) in which the colloid is dispersed .

It's pretty clear that "the colloid" is the dispersed phase, the internal phase, the substance that is microscopically dispersed evenly throughout the continuous phase, the dispersion medium. They mix colloid into the solution to make a colloidal system.

Re:Colloid

[SuricouRaven]

The researchers are mostly Japanese, and clearly english isn't their first language. The website is readable, but gramatically incorrect. I'm sure that they'll get the final article checked properly, but this is just a little public demonstration so a few minor errors from a second-language speaker are forgivable.

Soap Films?

[ThePeices]

The major problem with soap films, and one that I cannot see ever being fixed, is the total lack of compelling storyline. There is a reason why soaps have never made it out of daytime TV, and film adaptations would be a guaranteed flop.

What film studio in their right mind would want to fund a soap film?

Re:Ultrasonic Film Barrier

[SuricouRaven]

Think smaller. Airtight seals on holes a few centimeters wide, through which wettened tools (Or tools with hydrophilic coatings) could pass without breaking the seal. Handy indeed for laboratory environments when you might want to poke your instruments at a sample while keeping it within an inert atmosphere or protecting it from dust or microbial contamination.

Re:Ultrasonic Film Barrier

[c0lo]

If we could use ultrasound to structure an on-demand horizontal thin film barrier strong enough to resist convective air currents, we might have a really useful energy conservation measure.

Just vacuum the room out of any air and there you have it: no convective currents. Then use soap bubbles to insulate the room as you please.

(ducks)

Old Tech

[GrahamCox]

This sounds very much like how large-screen projectors worked, back in the 1970s.

not understanding this?

[slew]

From the comments I've read so far, it doesn't sound like people are understanding this technology...

Not sure if I understand it totally either, but basically, the website seems to talk about a mixutre of 2 colloidal liquids are used to create a semi-transparent membrane where they can use ultrasound to mimic some spatially varying BRDFs (bi-directional reflectance distribution function) effects. If you haven't heard of BRDFs, they are used in 3d computer graphics to simulate realistic lighting of different surface types (light from this angle and observer direction has the surface look a certain color whereas illuminating light from a different angle and observer direction looks a different color typically described as a 4D projected map). This give some images more realistic material look (as opposed to the strange plastic look where no matter how to turn your head or change the lighting angle the same average lambertian lighting model of the object is returned).

If I read the summary correctly, this device could probably also be used like those holographic stickers or lenticular viewers with projected light (instead of reflected light) allowing for more control in time and space and thus better realism. Unfortunatly, just like holographic sticker sand lenticular viewers, it's probably just a toy device, though maybe someday, the concepts could be scaled to do something less toy-ish...