Category Archives: Physics

Love circuit

Paper Circuits take 2 – on “embracing failure”

If you’d like to do this activity in your own classroom, see my first post on Paper Circuits, which includes links & information about where to get materials as well as some inspiration.

Five minutes before the end of study hall I called for cleanup and my students started unplugging their soldering irons and packing up their projects — Valentine’s Day cards made for their 4th grade buddies — and one of my students paused for a moment between switching off the soldering iron and slipping her card into her project storage bin. “I feel so successful!” she says, “I’m really proud of myself.”

One of my students carefully adding solder to her paper circuit in preparation for placing an LED down.

One of my students carefully adding solder to her paper circuit in preparation for placing an LED down.

If there are moments as a teacher that fill you with that warm, fuzzy feeling that makes you willing to keep working through those long hours for little pay and less respect, that’s mine: when a thirteen year-old girl looks at her electronics project with pride and satisfaction. There’s just something about soldering that makes it irresistible–the mixture of fine motor skills and hot molten metal which looks so very much harder than it actually is and perfectly primes kids for a swell of accomplishment. Kids love it.

The more impressive part of this project, of course, is its flexibility: students can make a beautiful work of art with a single LED in a simple circuit, or they can carefully plan out an extensive project with twenty to thirty lights in intricate patterns. One of my students, who had some experience with the tools needed from working with me in an elective, used arduino to program five separate circuits attached to an ATtiny microcontroller, each of which blinked in one of two patterns depending on which way he had flipped a switch. More than any other hands-on project I’ve ever done, Paper Circuits lets every kid have the opportunity to feel both challenged AND successful. Differentiation is always one of the most challenging things for a teacher to pull off well, but Paper Circuits does it with ease, so every kid gets to feel challenged without feeling overwhelmed.

Love circuit

The girl who made this circuit spent a long time with the multimeter carefully searching for the place where her copper tape had ripped and needed to be soldered together.

Most impressively, Paper Circuits is an amazing tool to teach students how to troubleshoot. There’s a good-sized list of simple mistakes that can break a circuit: the LEDs can be put on backwards, they can be poorly connected, or connected in a series circuit that needs more voltage than your battery can supply. A rip in the tape can cause a loose connection, or a stray blob of solder or bits of copper tape too close together can short out the circuit. One of the keys to this lesson is to give students a toolbox full of techniques to troubleshoot with. I’ve found that for most of my students, the breaking point that makes them give up on a project isn’t really whether it’s working or not or how long they’ve been struggling, but rather whether they feel like they’re making progress. There may be a long list of things that can go wrong, but it’s a finite list; before too long they’re going to find something to fix that they can take action on.

Teachers love to talk about “embracing failure” as a way to learn resilience, but that’s not what students really need. Children need to internalize the idea that success comes from consistent and persistent effort, and that when things don’t go their way they have the ability to make them better. They need to learn that they have power over their ability to succeed or fail, and that success is the result of hard work, not inborn talent.

Troubleshooting Techniques:

  • Flip the battery – if this causes the LEDs to light up, it means they’ve been soldered on backwards.
  • Try a new battery – maybe your battery is out of juice!
  • Press gently on the LED – if a little bit of pressure causes them to light up, they aren’t properly connected. Try soldering the LED into place again.
  • Search for the loose connection – use a multimeter on a setting that makes a noise when the circuit is closed. Place one lede at the start of your circuit, and trace along the circuit with the other. When the multimeter stops making noise, you’ve found the break in your circuit.
  • Search for a short circuit – look for places where the line of copper coming from the negative side of the battery and the line coming from the positive side meet. Separate them!

The best thing about these circuits is that when they work, they work spectacularly. A student might spend ten minutes carefully troubleshooting, and when they finally find and fix the problem, the card suddenly and sometimes quite spectacularly lights up. There is a single moment where it goes from broken to working that has led to more shouts of joy than I can count. Students don’t need to embrace failure. Failure isn’t much fun, and that’s not what they need to strive for. The failure is there to present a challenge that strikes the right medium between being difficult to overcome without exhausting a students options. It exists to make the eventual success that much sweeter.

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Paper Circuits: Teaching Science through Art

One of the most successful projects I have done in my entire teaching career, paper circuits is an activity that teaches the principles of circuitry while encouraging children to be creative and artistic.  The activity itself is simple: using copper snail tape, small surface-mount LEDs, and coin-cell batteries, students draw out circuits on a piece of paper.  The LEDs can be attached with scotch tape (great for younger kids!) or, if you’re feeling particularly bold, they can be soldered into place.

A star built out of a parallel circuit.

A star built out of a parallel circuit.

Setting up a simple circuit with a single LED is easy, but if you want to include multiple LEDs, you’ll need to learn how to make a parallel circuit.  In the process, you’ll run into a lot of difficulties: loose connections where you haven’t properly attached things, places where you’ve accidentally created a connection where there shouldn’t be one and shorted out the circuit, LEDs turned around backwards, etc.  This project is a perfect example of giving kids the opportunity to fail.  No one gets it perfect on their first try: they’re going to have to spend some time huddled with the multimeter, sliding the probes along the copper tape in search of the place where they have that loose connection.  The result is that they learn resilience and perseverance alongside the technical skills.

Place the circuitry on a piece of paper on the inside of the card to build art with lights shining through.

Place the circuitry on a piece of paper on the inside of the card to build art with lights shining through.

My 7th graders spent several lab periods working on this project; we were preparing for a visit to the elementary school on Valentine’s day, when they would be seeing their 4th grade “buddies,” the children they have been serving as mentors for.  Not only did they make cards for their buddies, when they visited they worked with their buddy to teach them how to make their own cards using a simple circuit and a single LED.  The project went surprisingly smoothly, even when it came down to 13 year olds teaching 9 year olds the basics of circuitry!

The best thing about this project is how it reaches out to a group of students who don’t see themselves reflected in the images of scientists and technologists around them.  Our society tends to code electronics as masculine, and girls who might have gotten the subtle message that circuitry is a boy-thing and felt uncomfortable or unwelcome playing with a breadboard take to the craft-based paper circuits model naturally.  The simple act of putting it on a piece of paper and letting them be creative with it removes the oppressive gender norms that might have driven them away…and that’s just the girls; this project let me reach a number of ADHD kids of all genders who view science as intimidating but who are completely comfortable with art.

An origami circuit featuring a push-button.  It was a lot of work to eliminate the short-circuits that appeared when the students folded this!

An origami circuit featuring a push-button. It was a lot of work to eliminate the short-circuits that appeared when the students folded this!

This is that rare project that seems to genuinely touch on all of those educational buzzwords that most schools only pay lip-service to: it’s a legitimately student-driven, space-to-fail, STEM, STEAM, interdisciplinary project.

If you’re interested in trying this at home, the Exploratorium  has a great write-up of what you’ll need to do it.  The places they suggest are a bit on the expensive side; I recommend buying 1/8th inch copper tape from Lucent Path, which sells 55 yard rolls of it for $9 on Amazon.  The 1/8th inch tape is thinner and easier to shape than the 1/4 inch stuff that the Exploratorium recommends.  LEDs can be purchased from Digikey – be sure you get the 3.2×1.6mm ones, as anything smaller than that is so tiny as to be extremely difficult to work with.  The trick to working with these tiny things is to stick them on a piece of scotch tape, and then use the tape to position them properly.  Coin-cell batteries can be bought in your average drug-store for about $5 each, but digikey has them for only about $0.25 each.  If you have any questions about this experiment, or how to teach it at home or in the class, let me know and I’ll be happy to answer them!