66% or better

Potting electronics with silicone

If you want to improve the reliability of your electronics, just cover them in silicone or epoxy. Potting, as this technique is called, protects your project from impact and loose wires, but most of the time ends up as a gloppy mess. [Charles] figured out an awesome way to make pro-looking potted electronics using silicone and a few supplies from the emergency room.

On one of [Charles]‘s trips to the ER, a nurse put Tegaderm on a wound and he noticed his skin could breathe. Figuring Tegaderm would also allow silicone to breathe, he asked for a sample and went back to the lab. After putting a few globs of silicone on a PCB, [Charles] wrapped the whole thing in Tegaderm. Much to his surprise, the silicone cured and made a smooth, glossy protective covering on his board.

[Charles] put up a Picassa album of his Tegaderm/silicone potted electronics, and we’ve got to say they’re looking very professional. This technique could also be applied to [Charles]‘ glass PCB touch sensor, allowing for the creation of clear (or at least tranlucent) PCBs.

After the break, you can check out [Charles] potting his ATtinyISP board in silicone with Tegaderm. One word of warning, though: don’t use a silicone that uses acetic acid to cure – that’s a death sentence to electronics. Luckily, there’s an easy test to see if your particular brand of silicone produces acetic acid while curing. Just squeeze a bit of silicone on a piece of scrap, and if it smells like vinegar after a while, don’t use it.

[Read more...]

We don’t need no stinkin’ packages!

DIP, SOIC, BGA, MLF or QFP?  None, so it seems.

This morning I received an email from Texas Instruments. Normally, these things go right into the spambox but this one was a bit unique. You can now buy some of TI’s IC’s without any packaging. Yup, just trays full of silicon squares. From TI’s point of view miniaturization has reached a point where that extra 0.1″ of PCB space is now too valuable to give to a piece of worthless plastic, and bonding micro-small wires to a silicon die is a feat that any manufacturer can preform with great accuracy, reliability and speed.

Whether this is a new paradigm in manufacturing or a premature April fool’s joke, if this process catches on smartphones just went from being almost unrepairable to 100% unrepairable, and ipod nanos might just start playing back 1080p video. It’s awesome and scary at the same time.

Now, are they crazy, or just ahead of their time? Tell us what you think.

Gas containment for laser cutters

Tired of breathing all the noxious fumes your laser cutter puts out? Yeah… we don’t have a laser cutter either. But [Jeri Ellsworth] does and she needed a way to evacuate off-gases generated during cutting so that they don’t damage the laser cutter, or her lungs. What she came up with is a containment box that attaches to a pump system.

The problem is that you want to keep the gases away from the laser cutter hardware but you still need to be able to shoot the laser at your work material. Her clever solution is to use a silicone wafer like the ones with which she makes integrated circuits. They allow the infrared laser to pass through without being chopped in half. What you see in the image above is a red box with the round wafer in the center. Near the bottom of the image is a clear window so you can see what’s going on with your work piece. But to get the full idea you need to watch the video embedded after the break.

We can’t help but think she’s building this in preparation for some more chemistry hacking.

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Oogoo, a home-made Sugru substitute

If you follow Instructables.com, it might seem like every third article lately is about Sugru, the nifty air-drying silicone putty that’s good for all manner of repairs and custom parts. It’s fantastic stuff (and we love their slogan, “Hack things better”), but one can’t (yet!) just drop in on any local hardware store to buy a quick fix…so [mikey77] has cooked up a recipe for a basic Sugru work-alike. His “Oogoo” (a name likely inspired by oobleck) is a simple mix of corn starch and silicone caulk.

A two-ingredient recipe would hardly seem adequate material for an article, but [mikey77]’s left no stone unturned, providing an extensive tutorial not only on mixing the compound, but how to add colors, cast and carve custom shapes, and how his home-made recipe compares to the name brand product. As a bonus, the article then drifts into a little Halloween project where he demonstrates etching conductive cloth, how to make conductive glue, and other hands-on shenanigans.

Transistor fabrication: so simple a child can do it

If manufacturing printed circuit boards has become too easy you should try your hand at producing transistors. [Jeri Ellsworth] put together a collection of videos outlining the process. These go way beyond the IC fabrication we saw from her in the past. It doesn’t take much, a 1000 degree oven with steam option, silicone wafers, and a variety of chemicals. We’ve embedded the instructional video as well as two demonstrations of her N-style FET after the break. [Read more...]

Cold climate solar water heater

Here’s a solar water heater setup that augments your home’s water heater instead of replacing it. The system monitors a solar collector panel on the roof for temperature. If the temperature is warm enough, a photo voltaic cell powered pump circulates cold water through the system. The heated water returns to the top of the home’s water heater. Unlike the warm-climate solar heater we saw earlier, this one can withstand freezing because it uses silicone tubing in the collector.

[Thanks Marius]

Sugru – moldable silicone adhesive

Reader [James] told us about a new product developed with hackers in mind. Sugru is a silicone-based adhesive that cures at room temperature. It is moldable and once hardened it remains slightly flexible. You can see in the picture above that it has been used to create a hook but the inventor shows off a slew of other uses such as replacing missing feet on a chair, molding hand grips, and waterproofing. One of the most enticing aspects is that Sugru will create a chemical bond with smooth metal.

The product reminds us of the two-part earplug material used to ruggedize electronics from a while back. The difference is that Sugru is one part and is an adhesive. It comes as a satchel full of individually-sized packets. To use it, choose how much you need, cut open the package to reveal the product, then knead and mold the chewing-gum-looking substance to fit your needs. Check out the demonstration video after the break.

Want to try some out? Yeah, so do we but it seems they’ve already sold out of their initial supply (good for them, bad for us) and we haven’t seen word on pricing. We’d love to use this to mold enclosures, and for about a billion other things.

[Read more...]