Whiteboard Alternative

The Idea

I work in the semiconductor industry, and nearly everyone has a whiteboard in their cubicle to assist the many discussion we have about equipment, processes, statistics, etc. Whiteboards are a cheap, effective, and relatively clean alternative to projectors, blackboards, etc. But they still require consumables, and they're not totally clean.

For a while I've been wanting to see if I could develop a better alternative. It would be nice if I could improve cost and invent something manufacturable and marketable, but at the very least it would be fun to have something unique for me to use.

Progress

Giant "Magna Doodle"

This would be a 3'x4' Magna Doodle board. Magna Doodles use an opaque ferrofluid trapped inside small cells. When a magnet is touched to the surface, the iron particles in the fluid come to the surface creating dark spots / pixels.

Pros:

• No mess
• No consumables
• Variety of cheap magnets

Cons:

• Poor resolution
• Monochrome
• Wears out with use
• Expensive to piece together or custom build one large sheet
• Hard to erase just one small section

Magnetic Viewing Film

 Viewing film operates on a similar principle as the magnadoodle, but the fluid cells are much smaller, and typically green. I've never played with it in person, I should buy a sample to see how well it would work.

Pros:

• No mess
• No consumables
• High Resolution
• Variety of cheap magnets

Cons:

• Monochrome
• Slow response?
• Have to piece multiple sheets
• Hard to erase just one small section?
• Fragile 

8/9/2014 - I got my viewing film last week, just a small sample. It's really fun to play with, but the difficulties in using it for drawing became quite clear. The film is plenty responsive; it's too responsive. It can produce decent contrast, but when you pull a permanent magnet away the contrast changes as the fields move through the film. Wherever you start and stop a line will look blurry. You'd have to use an electromagnet that activates when you touch the surface. That's doable, but more hassle. The last drawback is with erasing. You have to hit the entire board with a uniform field from the backside. That's just a little too much bulk and complexity for me to mess with right now. 

E-Ink

 E-Ink is a new technology used in some e-readers. Instead of using a ferrofluid, electronic ink puts a dark ink/oil inside the microcavities along with charged, white particles. The microcavities are coated top and bottom with a conductive film. Applying a charge to the film can move the white balls to the top or the bottom to provide pixels and contrast.

Pros:

• High resolution
• Long life
• Robust housing
• Multiple colors possible.

Cons:

• Requires electricity (could use manual generation)
• Micro-fabrication is expensive and difficult

This is my favorite method. I would like to learn how they manufacture these displays so I could make one of my own. I emailed the company to see if they would sell me a batch of ink that I could put on my own surface. Of course I got no response.

Giant BoogieBoard

The BoogieBoard is an LCD display that does not require power to retain an image. It uses chiral liquid crystals to form a cholesteric, bi-stable display. The crystals are oriented in parallel planes which align in a cork-screw fashion. Within each plane the crystals lie flat, aligned uni-directionally. This crystal medium will selectively reflect light depending on crystal orientation. I found the actual manufacturing process in a whitepaper written by Kent Displays. I have enough information on this idea to actually try building a device.

Micro Magnet Array

Giant grid of magnets with poles all in the same orientation. Pull forward or push back. Same principle as magna doodle only with magnets instead of iron. Magnest would have to be small enough and far enough apart to reduce their influence on each other, and that will limit resolution.

Dirt Drawing / Sand Writing

Writing in dirt may be the oldest form of written communication. For this project I'd use sand. I'm sure there are several ways this concept could be realized. You could have a tray of sand and use it like they do in the high contrast, flat sand art. Or you could have a packed surface using etched lines. I would need to think of a good way to make a vertical unit. It would be heavy.

Generalizing the Principles

Okay, now that I've gone through a few different ideas I think I can start distilling the underlying principles by which these devices operate. Basically you are creating contrast between a background medium by adding or moving another material. The forces being applied are electric, electrostatic, magnetic, and direct physical contact. If the background medium is liquid, and the secondary material can diffuse in the medium then the secondary material must be physically isolated to keep it evenly dispersed. If the secondary material can freely move, then you must deal with a mess or have a recycling method.

Types of Forces:

• Applied
• Direct
• Pneumatic
• Hydrolic
• Friction
• Spring
• Gravity
• Electromagnetic
• Electrostatic
• Magnetism
• Nuclear