Our own [Eliot] dug this one up from the grave. While the recipe has been online for a while, do you know many 10 year olds who made their own Aerogel, that wonderful insulator that’s essentially gelled air? [William] made some(cache) for his science project in 2002. He started with Silbond H5, a combination of ethyl alcohol and ethyl polysilicate. You can get the MSDS after a painless email registration on the Silbond website. After the gel is formed you have to soak it in an alcohol bath to make sure all water has been removed from the structure. Then the gel is placed in a drying chamber. Liquid CO2 is forced into the chamber to displace all the alcohol in the chamber and the structure. Once the the alcohol is gone the supercritical drying phase begins. The temperature is raised to 90degF and the pressure is regulated to 1050psi. At this point the liquid CO2 in the gel structure takes on gas properties (looses surface tension) and leaves the silica structure. All that remains in the chamber is your new Aerogel which is 99% empty space and 1000 times less dense than glass.

Of course, if you’re lazy, you can buy some here.

[bgugi] was the first to notice that yesterday’s post had been seen before, tucked away in an extra last year. (I do check for these things, but it slipped through.) I honor of my little lapse, here’s a fully loaded extra.

[Matt] scored some interesting hardware next to one of the local dumpsters. He also just put up part one of his coil gun based on ten $1 disposable cameras.

[Darren] sent in this USB webcam that was mounted in a Canon FX SLR body. Now the cam can be fitted with old (inexpensive) lenses for better performance.

[Brandon] really likes his XBox live – enough to set up access via Sprint EVDO and install everything in his Mini Cooper with a set of VR glasses and controller in the glovebox for instant access.

These were all over the place this week, but I wanted to put them out there. [Pablos] showed BoingBoing how completely lame RFID enabled credit cards are. And it’s way to much fun to watch this dog play with his own robotic ball tosser.

[Jason] sent in his altoid tin guitar – he slapped a piezo inside the tin to get signal out of it.

[David] sent in his older, but still awesome Segbot. It’s a balance bot that’s controlled via wireless modem with camera feedback.

Last and definitely not least, [Basil] sent in his Midistrip guitar mod. He added a capacitive touch strip to the body of a guitar and uses it to create midi output. Check out the demo vids here, here and here.

[Nuri] sent in his rather interesting gaming feedback device. The TrakonyaMutatorUSB is a USB based armband that’s designed to shock you when you get shot or killed in your game. I can’t comment on the safety of this thing, but I guess it could be a good gift for your enemy gamer.

Update: Just to clarify a bit, This is built by [Nuri]. He offers them for sale (via paypal I see), but it is his work. It would be nice to see the design, but I can see some reasons why he might not want to release it to the public.

[Shadow] sent in this handy idea. For many, it’s sort of a captain obvious hack, but I’m hoping that this might keep a few of these things out of the trash. He needed to send video around the house from a media PC, and happened to have an old XBox RF modulator sitting around. He popped it apart and located the audio and composite video inputs. To get the signal to the rest of the house, he plans on installing a distribution amplifier that’ll amplify and split the signal to each TV set.

[Jim] sent in this interesting laptop modding project. He started with a Spectrum ZX and a Toshiba Libretto 110. The libretto kept its brains, but the lower case and keyboard was replaced with the ZX hardware. Since both machines use matrix style keyboards (but different matrix layouts) he was able to create a passive adapter circuit to match things up.

[Andrew] sent in his low voltage coil gun. He used some control hardware that most hardware hackers probably don’t have on their shelf, bit it’s still a good proof of concept. Each coil is driven by a dedicated relay, and a PC power supply feeds the system juice, while a programmable logic controller does the work. Since it’s just a matter of triggering the coils in order, the PLC could be easily replaced by a micro controller.

[David]‘s been building his own game platform based on an ATMega chip and an eight by eight LED matrix. Looks like he’s used the project as an excuse to get familiar with eagle and doing his own PC board design. Even if the game doesn’t really interest you, future project designs can probably benefit from his roadmap.

Want to get your laptop custom etched… for free? During the next couple of months, I’ll be giving away some free etching sessions. How do you get one? Just submit a fresh new hack via the tips line. If it makes the cut and gets published, you’ve got a chance to get your laptop or gadget etched in this 45 watt epilog laser cutter. Here are a few guidelines to help you win:

1. Make sure it’s fresh. Use google for 10 seconds to make sure it hasn’t been published on a major blog already.
2. Make sure it’s got a picture – everybody likes a good visual aid.
3. You’ll be more likely to win if you’re submitting your own work.

Good luck!