I was notified late Wednesday that I have been awarded the October 2011 grant from the Chicago Awesome Foundation for completing the full prototype of the Scanning-Tunneling Microscope. Their posting is over here. For the record, yes, I officially love the Awesome Foundation.
The version 0.1 electronics in the video posted on the Make blog was a poor implementation of a good analog design with a microcontroller slapped to the inputs. I’ve since learned that analog is weird compared to digital, and getting those two worlds to talk properly involves a lot more finesse and art than science and equations (equations do get you into the ballpark, however).
I’m nearly done with a complete redesign of the digital and analog electronics (now at version 0.3). The new electronics incorporates nearly complete digital control of the STM (I’m working on ways to further increase the control the microchip has over the STM to include gain control of the many op-amps). Thanks to Idea Petri Dish for the assist on analog circuit design and troubleshooting.
With new electronics comes new firmware and software of course, which is in-process.
I’ve done a very rough draft of the vibration dampening table design. I’ll be using a classic floating gravestone style table – a heavy slab of material suspended by rubber bands, surrounded by a support structure. It’s not fancy, but it works.
I’m working with Bart Dring, of MakerSlide fame to design the rough approach (basically a screw, direct-driven by a 400 step motor and a 1/16th step driver, like the pololus popular with the RepRap folks).
I quit my job to pursue my dream of working in the device design industry, so if you’re feeling particularly generous, please purchase a periodic table – 100% of the proceeds goes towards funding this project.
If you want to find out when kits are available (soon, I hope), sign up here.
I recently had to patch a large hole in a wall (a past owner of my house used shoddy workmanship and zero planning).
Over the weekend, I started painting the patched hole – primer, then house paint.
While painting, I started thinking – modern house paint is a pretty amazing mixture of chemicals. House paint needs to do and be a lot of things at different times – it needs to coat and stick to the paintbrush, it needs to coat the wall smoothly and consistently, hide everything underneath, dry quickly, achieve a specific surface texture, be resistant to fading, chipping, and sometimes even mold and moisture. Oh, and it needs to come off your tools easily when you’re finished painting.
Modern house paints can contain thousands of chemicals, I’ll cover the major parts:
This is an old article, but it’s still very relevant. The June 2006 edition of Wired Magazine has this article detailing the rise and fall of the garage chemist: Don’t try This At Home (here it is all on one page, but without all the pretty pictures).
The reason you should read this:
Taking chemicals and lab equipment away from kids who love science is like taking crayons and paints away from a kid who may grow up to be an artist.
I know I can’t start a discussion about at-home chemistry without mentioning the (in)famous Golden Book of Chemistry Experiments. Some overly dramatic people have called it a banned book – it isn’t, but it is a bit out of date and presents some experiments that aren’t exactly safe for unattended kids (or even adults) to perform.
Published in 1960 and updated in 1962 and 1963, and now widelyavailable in pdf form on the internet, this book was an inspiration to many a home chemical tinkerer.
There are several basic safety flaws with the book that prevent me from recommending it as an experimental handbook. I found these in a 10-minute review:
teaches you to make chlorine gas ?!!? seriously? WTF!!
has you taste a weak NaOH solution – I prefer reading books that don’t try to poison me…
shaking test tubes by putting your thumb over the opening and shaking – another bad no-no
people sticking their fingers into boiling milk? what?
Things I do like about it:
It is a great, concise (only 114 pages) background on basic chemical theory and history
The majority of the experiments are good (but I disagree with the methods the authors use)
So, for homework, I assign everyone out there to skim through the Golden Book of Chemistry Experiments and find the most awesome examples of terrible safety and the most inspiring and interesting experiments and theories it discusses. Discuss in the comments…
Low resolution image of the Golden Book of Chemistry Experiments courtesy of Wikipedia.org
Arrgh, I can’t believe I just noticed that NO ONE in this book wears any safety gear. There are no gloves, goggles, aprons. These kids are doing chemistry in their Sunday best!!! I don’t think the author mentions anything about real fire extinguishers either (but they do talk about how fire extinguishers work…).