Damask Circuitry

I got the idea for this pattern from the wee blinky, an astable multivibrator that flashes a pair of LEDs.

To create a knitted circuit pattern, I tried to minimize the number of places where traces cross over each other and require jumpers. 

It was fun to plan, and after I got one working, I started multiplying it to create a pattern reminiscent of damask.

(I'm having a strong urge to reupholster the couch in this pattern, now.)

Looking Like An Engineer (Part 3: A Call for Collaborators)

I was taking a yoga class a few years ago when I noticed a fellow student with a circuit diagram tattooed on her forearm. After class, I asked her about it. She told me she was a theater sound engineer, and the circuit was an op-amp, part of her audio console.

I've been wearing a circuit on my own forearm lately. The first time I wore it on the train, a man sitting near me kept staring at it, and finally complimented me by saying "You look like you got it going on!" I didn't even have it turned on at the time-- just a few LEDs and a battery. It made me think of the woman with the op-amp tattoo. I wondered if displaying it gave her more tech cred.

I, too, would like to wear an op-amp, and a number of other circuits as well. Because apparently I need some tech cred. Because electronics are fun. And because, frankly, it looks cool. So I've been working on methods to knit circuits with all the standard electronic components, in addition to the ever-popular LED. 

The lovely thing about these circuits is that they're great conversation starters. People who know electronics want to know how they work. (As do people who don't.) I don't suffer from "invisible woman" syndrome* when I'm wearing them.

Clothing has long been a way to advertise status; for women it's also been a means of displaying "maker" skills, and of building community around the sharing of those skills. I think it's time we use it to create some new "Engineer" archetypes. 

So I'm looking for collaborators -- engineering women with tech skills you want to wear on your sleeve (literally). What is your "circuit tattoo"? Would it fit on a cuff? A cardigan? A floor-length gown? You design the circuit board, I'll knit it, and we'll have a Stitch-n-Solder bee to build it. Model your new threads and re-define "what an engineer looks like."

 - It'll probably work best if you are also in Chicago.

- The more visible the circuitry, the better.

- Circuits that make sound or light or movement get bonus points.

- So do circuits that give you super powers.

If all this sets your gears a-turning, get in touch and tell me what you want to build.


BTW, If you want to knit your own circuit boards, I'm working on an instructable for that. Stay tuned.


*Sheila Miguez sent me this link to an amazing talk by Naomi Ceder, a programmer who transitioned from male to female. Starting at 19'50", Ceder discusses what the Python programming community is like for women (trans or not). I love her statement that she was worried about being harassed at PyCon the first time she went to the conference as a woman, but discovered instead that she was now invisible.

Looking Like An Engineer (Part 2: Historic Trivia)

Clearly, this is not what an engineer looks like.

Historic trivia sent to me by Kevin Coughlin, in response to Part 1:

Hollywood bombshell Hedy Lamarr invented the concept of frequency hopping so American torpedoes could foil German submarines in WWII. The Jewish-born Lamarr had recently fled Europe and an unhappy marriage to a Austrian arms manufacturer connected to Hitler and Mussolini, who frequently took her to business meetings. She developed the idea with composer George Antheil and in 1940 they tried to give the technology to the U.S. Military by presenting it at the National Inventors Council. She was reportedly told "she could better help the war effort by using her celebrity status to sell War Bonds." The technology was finally adapted by the U.S. Military during the 1962 Cuba missile crisis, and is now used in cell phones and Wi-Fi.

"The U.S. Military really doesn't need your help. Why don't you go sell War Bonds, instead?"

Looking Like An Engineer (Part 1.5: comments on Part 1)

My first post on this topic generated a lively discussion on both Facebook and the Pumping Station One google groups list. After getting permission from the participants to use comments and names (or not), I'm posting a few highlights here.

I'll start with the women:

Hailey Willis:

I've had all the same frustrations as a woman who's body shape defies pants, and who works in a male dominated field.


I hate clothes because I hate my body shape... I hate wearing baggy tshirts and jeans, but nothing else really fits right. any interactions I have with people are negatively impacted -- frumpy clothes, fat body, large chest. At jobs I've had people stare at my chest rather than me and it was disconcerting (e.g. especially when it is the CTO of the company I work at -- how seriously will someone who stares at my chest take me as a technologist in that company?). ...[I love] working from home -- anyone I interact with isn't going to immediately filter what I say through my looks or gender.

Looking Like An Engineer (Part 1)

"Hey, guys! Does this sundress make my brain look small?"

I attended my first Maker Faire in Detroit, at the Henry Ford Museum, with my colleague Ben (who, like me, is a professor at Columbia College Chicago). We drove out in Ben's car, and got hotel rooms so we could attend both days.

The first day was sauna-hot, even in my faded denim skirt and old t-shirt. Most of the Faire was on the blacktop of the museum parking lot, and bottled water was a poor substitute for shade. Still, we had fun and were able to see a lot of very cool stuff.

The second day I opted for a simple cotton sundress, the most comfortable thing I owned for hot weather. I'd found it on sale at a stylish boutique, and received compliments from other women every time I wore it.

My experience the second day of Maker Faire was waaaay different.

For example: a man was displaying a mechanical contraption he'd fabricated with a metal lathe. I was just getting into "making" at the time, and was fascinated by machining. Tell me more, I asked. He started to, and then, Ben wandered up. Clearly we were at the Faire "together" (actually, we're work colleagues and friends-- we both have significant others). And so the gentleman stopped making eye contact with me and started talking exclusively to Ben, who had little interest in the subject, but listened politely.

I guess the exhibitor assumed that if I was interested in machining, my "date" would be fanatical about it. Or maybe some men feel it's rude to talk to a woman if her "date" is present. Even if her "date" has zero interest in what the guy is saying.

This threw me a bit, and I started noticing it at other booths. If Ben was with me, guys made eye contact with him, and ignored me. Every time I noticed it, I shrank a little bit more in my cheerful yellow sundress, and felt a little less included.

We made our way to several tables covered in old circuit boards and half-dismantled appliances. What fun! A man stood behind the table, handing screwdrivers to children engrossed in the dead hardware. As we walked up, he looked at Ben and said, "This is a teardown table. You can take apart anything here to see how it works." And then he made eye contact with me and added "You can also make jewelry with the resistors." 

What did he just say? I honestly thought I misheard him so I asked Teardown Guy to repeat himself.

"You can make jewelry with the resistors," he repeated and walked away. (I think the expression on my face right then told TG to find somewhere else to be.)

"I'd like to make jewelry with the resistors," Ben called after him.

Despite TG's comment, I couldn't resist the offerings on the table, and grabbed a screwdriver to play. Ben eventually moved on, and I turned my attention to the guts of a sewing machine (I'd been reading about cams and gears recently and was fascinated). The gears were greasy though, and I was making a mess. So... I asked Teardown Guy if I could take it home, as it was nearing the end of the Faire and the crowds had waned.

"Why do you want to take it home?"

"I want to take it apart to see all the gears and cams, but it's greasy and I don't want to ruin my dress."

"Well..." he looked skeptical, "I want to make sure you don't think you could use it as a sewing machine. It won't work."

No kidding.

I assured him that that was not my intention. I added that I was an artist (which generally gives me a free pass for all sorts of strange behavior) and that I wanted to make a kinetic piece using gears and cams.

He conferred with another guy running the booth (who'd been watching from a lawn chair and seemed very amused that Teardown Guy was making an ass of himself). TG returned and said, "You can take it, but only if you email us a photo of what you build with it." TG handed me a card for the local business that was sponsoring the table. 

I pulled my business card out of my purse and handed it to him.

"My website is on there. Check it out if you want to see what I build."

He examined the card like a bouncer checking for fake IDs.

"You look really young for a college professor." 


After I dropped the box of machine parts at the car, I moved on to the indoor booths, which included a table selling piezo contact mics. I make these with my students, so I asked the seller about the housing they were using. The guy took that to mean I needed an lesson on how contact mics work. I started to protest, and he enthused, "It's really simple! Let me show you!" convinced he was proselytizing to someone who thought science "was hard."

If I hadn't been worn down by the heat and all the other weird encounters already, I might have explained but it was too much. That was it, I was done. I left the Maker Fair area and wandered into the museum exhibits.

I found myself in an exhibit on Amelia Earhart, complete with a plane, a mannequin in her likeness, and a plaque.

The plaque had a quote from her on it. It said,



Amelia was right. I needed a change of wardrobe. 



7/27/14 The plaque did not actually say this. But it really should have. (Please note that the quote was not intended to mislead anyone, rather it was an attempt at magical realism. Said attempt apparently failed given that several people have asked me if the plaque did in fact advise against yellow sundresses.)

6/1/14 Edited to add links and the last sentence of paragraph 2, which was left out of the original post. For the male perspective on some of these awkward exchanges, see the next post in the series. The entire series is available here.

Fun with RGB LEDs

Knitted circuit: 5mm RGB fade LEDs, 8mm blue LEDs, battery and switch.

The LEDs (both the blue and the RGB fade) are wired in parallel, soldered in place. Fun fact -- red draws the most current. So, when the color-changing LEDs turn red, they draw so much current they starve out the big blues. The result -- the blues fade in and out, no micro-controller needed.

Two knitted circuit boards, with iron-on backing.

My first gif. (The color changes are actually very slow and gradual, not blinking.)

Craft/Work Show

My paper speaker was included in the show, "Craft/Work," which opened at Beauty and Brawn Gallery, April 18. 

The show's organizers, Nora Renick Rinehart and Rachel Wallis, were fantastic to work with, and immensely patient with all my technical issues (more on that below).

Photos of the opening

This poignant quilt, embroidered with the names of Chicago homicide victims, was detailed in the press.

My speaker

I actually had a slightly different speaker intended for the show, but I had to swap out because the epoxy glue-down was too thick, which ended up muting the sound. The original is such a lovely object, though, with beautiful handmade paper from my former student, Alex Borgen, that I'm contemplating other uses for it. Perhaps a paper lantern?

Why Knitted Circuits?

(a knitted circuit board, ready for soldering.)

The short answer is, I can't sew.

The long answer....

E-textile platforms are based on designing materials to fit textile fabrication methods, resulting in conductive thread and components mounted on PCBs designed especially for sewing (for example, the Flora platform).  Perfect for experienced sewers interested in soft wearables.

However, the conductive threads often used for e-textiles can be unstable as conductors. Silver-plated thread oxidizes over time and becomes non-conductive, something I discovered after buying a large spool and leaving it out for months. (If you have some, store it in an airtight bag.) Stainless steel thread does not have this problem, but it does have higher resistance.

Creating solid connections with the thread presents another challenge.  It requires hand-sewing skill, stitching the thread through the component lead multiple times, knotting tightly, and adding glue for security. The whole process makes me want to reach for my soldering iron.

But... the conductive thread widely available in the US is not solderable. Conductive threads made with polyester or nylon wilt or melt under heat. Solderable conductive thread is available in Europe, made with Kevlar. The minimum purchase, a kilogram, starts around 60 euro, from the company, Karl Grimm & Co. With shipping, you can expect to pay over $100. One of the creators of the phenomenal e-textiles resource, How to Get What You Want, Hannah Perner-Wilson, sells small spools of the Karl-Grimm conductive thread reasonably-priced on Etsy, but it's still not cheap enough for me to create artistic-experiments-with-abandon.

Additionally, conductive thread introduces resistance to the circuit-- it just doesn't conduct as well as the copper wire used in conventional circuits. Arduino-based circuits can compensate for this, but I'd like to build circuits using conventional components, as well.  So I'm investigating how to apply textile techniques to conventional electronic materials. After much research, I've developed a tool-box of methods around my favorite skills of soldering and machine knitting. I'm documenting my methods here, as they evolve.

This approach is not for everyone. I've taught a number of basic knitting machine workshops at Pumping Station: One, and some people love it, some people, not so much. Even if you can machine knit, machine-knitting wire is an advanced technique.  I don't recommend trying it until you're comfortable working with "difficult" yarns like cotton and silk. But once you do get the hang of it, knitting PCBs is soooo easy.....