The talk was by Saya, and she mentioned that she wanted a boyfriend who smells of campfires.

I stopped working on my slides and raised my hand.

-all the time?

-yes.

Tim raised his hand.

-even right after a shower?

-yes, right out of the shower.

I looked at Tim and said “I’m sure I can make that scent, let’s try it!”

***

So, fast-forward about 26 hours and Tim and I win the BarCompany competition with a prototype of our brand-new all-natural campfire-scented cologne, Smoque. In the image, the bottle on the left is the actual cologne, the bottle on the right is the concentrated scent, and the hollowed-out stick is a packaging prototype.

The company name will be Rugged Scents (still under construction).

If you’re interested, please sign up here to find out more about Rugged Scents, when our first cologne (Smoque) ships, and what other scents you are interested in seeing us produce.

New website here.

Google group here.

First meeting will be on Sunday, September 12 at 4pm at Pumping Station: One in Chicago 3354 N. Elston Ave.

Feel free to bring your enthusiasm and ideas for problems that are best tackled via open software style approaches. Also, all realms of science that study natural phenomena are welcome: astronomy, physics, chemistry, biology, math, engineering, and many more I’m sure I haven’t mentioned.

The answer I came up with is to use reflected laser light to amplify the movement of the scanning head.

To test the new head, I mounted a small mirror (actually a sequin, they’re lighter) in the needle mounting point, shined (shone?) a laser at the mirror to see if I could see movement in the reflected laser point as the scanning head moves back and forth.  What I saw was a little movement, but the laser reflection was so diffuse and the movement was so much smaller than the laser reflection that the movement didn’t show well on the video I shot, so you’re going to have to put up with still photos until I acquire better mirrors and/or a more focused laser.

Laser and sequin

Diffuse, reflected laser light

Before: in a cigar box

When I first mentioned I was going to demo the early prototype of the STM at the Open Science Summit, everyone who had actually seen the thing asked me (worriedly) how I was going to get it through the security checkpoints at the airport.

Looking for advice, I brought the prototype to Steve Y., the experienced head of security at my office, and asked what he thought I should do. “Well, what you have here doesn’t look great, but it’s not bad. Here’s what I’d do: put it in a nice box, put some official labels on there, put some kind of identifying label on there, and then send it through the X-ray machine alone. You’ll be fine.” With this pattern to follow, here’s what I did:

The Case:

I purchased a simple black blown-plastic box from American Science and Surplus.

Simple box from American Science and Surplus

When I got it home and cleaned it off, I added an ESD sticker from one of my parts purchases and hot glued a lining of anti-static foam (also from parts purchases). I also added a few strips of Velcro to the top area in case I want to have a tool or something stuck on the upper section of the box in a later incarnation.

Electronics sitting on a bed of anti static foam.

Once that was done, I used a label maker to create a few labels:

• “Fragile Prototype” – on the front
• My name and phone number – on the front
• “Fragile” – on the back

After: labels and stickers applied

Packing the Electronics:

I put the electronics in the box with a little extra padding to prevent things from bouncing around.

The only thing in the box is the prototype and padding – no tools, extra parts, batteries, additional devices, or anything else. That stuff can all go somewhere else.

At the Checkpoint:

At the checkpoint, I simply went through as normal, except I took the electronics box out of my bag and placed it on the conveyor belt alone. In my two passes through security checkpoints, no one said anything to me, so I guess this was a success.

Final Thoughts:

I had just one wire break during transport, so next time I’ll pack it a little more carefully (or just get better at breadboarding).

The overarching philosophy I followed with this project was, through my actions, to tell as transparent (geddit? x-rays? transparent?) and simple a story as possible about what I was carrying.

The more objects and cruft near the electronics you’re carrying, the more misunderstandings and inspections you’ll have to deal with.

I’m working to get the STM working as fast as possible, but it’s not 100% – I’ve got basic functionality tested and working, but no images yet – I’m hoping to have images within a month or so.

Current work:

• A new scanning head
• Complete the mechanical supports and approach mechanism (current state photo of the mechanicals, above)
• Programming the arduino and the python script that gathers the image data
• Final electronics testing
• Getting everything prepared for air flight (expect a post in the near future on preparing electronics for TSA inspection)

Here is a video of my latest tests – the digital side talking to the analog side and driving the scanning head (faintly):

If that’s not enough for you, here is some good background info to read about STMs:

Introduction to Scanning Probe Microscopy

Wikipedia Scanning Tunneling Microscope (STM) article

And you may be interested in the ChemHacker youtube channel.  It’s a bit sparse now, but keep an eye out for updates as this project proceeds.

1. In case you missed the youtube video, the STM is now electronics hardware complete – well, I have a very small change coming in the mail (a two-in-one DAC chip) to replace the two separate DACs.  This may improve the code efficiency slightly, but I’m going to wait a while before I implement the change.
2. I’m working on the programming right now, and not sleeping much while I do because (see below)…
3. I have been invited to display the STM at the Open Science Summit in Berkeley at the end of the month.  If you’re there, stop by the Berkeley International House and say hello – I’ll be at the hardware tables.

…I have so much work to do between now and then…

video after the jump:

Things to do before the STM is complete:

• Connect the digital and analog sides (about an hour of wiring)
• Build the physical STM support (about 4 hours of machining)
• Finish the serial transfer code in python (?)
• Wet etch a tungsten tip (about an hour)

Until now.

I found this old Faygo-labeled shelving unit in a nearby alley:

After a (lot of) cleaning, here it is holding tools and a wide assortment of chemicals in the underground ChemHacker Lab:

Now that I have Faygo-themed shelving, perhaps I should look into teaching Juggalos some f’ing Science?

As I mentioned earlier, I’m working on programming an arduino interface for the ChemHacker STM.

The arduino currently has to handle the following tasks:

• serial control of the five digital potentiometers (amplifier gain control)
• serial control of the 24 bit DAC (signal input to the microscope)
• analog signal processing from the microscope (via built-in ADC lines)
• serial data to the computer of the scanned data (for image processing)

A future task for the arduino may be:

• automated control of a stepper motor (for sample approach and control)

My road map for programming is as follows:

1. establish serial control of the potentiometers
2. establish serial control of the DAC
3. establish signal into the ADCs
4. establish serial data line to computer (and figure out some kind of live image processing system)
5. interface with microscope circuit(s)
6. establish stable scanning

As always, things take more time than you think – I foolishly thought I could get steps 1 and 2 done in a few weeks.  After nearly a month of struggling, I finally have (1) accomplished, and with some help from some excellent electronic engineers, I’m quickly closing on (2).

Many many thanks to all the people who publish their SPI code on various Arduino boards, without your examples, I never would have gotten this far…

Here’s what I’ve learned from weeks of banging my head into walls: the entire SPI setup must be used for the arduino’s SPI to activate – that includes declaring pins you don’t intend to use (like the MISO and the SLAVESELECT)

What you see in the photo is the red sanguino microcontroller, the green main amplifier board, the tan tunneling current amplifier, and on the breadboard are the digital pots and 24bit DAC I’m using for controlling the microscope. At the top right is the microscope nanopositioning head.

The end result of this project will be an open source STM with modern electronic controls.