Yesterday I got to do an awesome STEAM program with a group of school-aged kids, making DoodleBots (also known as ArtBots or ScribbleBots), which are simple robots that can draw using magic marker legs and a vibrating motor to produce movement. Electric toothbrushes from the Dollar Tree proved to be an extremely cost effective resource, providing the motor, battery case, circuit, battery, and switch, all for a dollar. There are many articles on the web about these, but I first got the idea from Anne of "So Tomorrow" and followed the link she provided to another article by the Cheshire Public Library.
Recommended Ages: 5-12
Recommended Group Size: The smaller the better, maximum of 20.
Time: 1 to 1-1/2 hours (we managed in an hour, but I would strongly recommend 1-1/2 hrs)
Budget: $1.50-$2.00 per bot
- GB or Luminant brand electric toothbrushes from the Dollar Tree ($1 ea)
- Foam pool noodles, cut in 4.5" pieces ($1 ea, one noodle makes 10 pieces)
- Markers, 3-4 per person ($1/set of 12?)
- Rubber bands
- Electrical tape
- Duct tape
- Glue, glue dots, hot glue
- Misc. craft supplies (googly eyes, pom-poms, pipe cleaners, feathers, jewels, etc)
- Large rolls of art paper (the smoother the surface, the better)
*Note - Although this program worked ok the first time, the second time we did it with a larger group, we had significant technical difficulties with the tape stretching and causing the connections to loosen and the motors not to work properly.
If you are working with teens who can deal with trouble-shooting themselves, then you might want to stick with this method so they can really see the motor and circuit, but if you are working with younger and/or easily frustrated kids, then skip steps 1-5 and follow the alternate protocol.*
1. Start with the cheap Dollar Tree toothbrush, which comes with a AA battery, and disassemble it by pulling off the cap containing the switch, then remove the battery holder and motor. I found the easiest way is simply to bang the bottom once or twice against the table to get it to come down to the end and gently remove.
2. You will end up with the brush (which can be discarded or saved for another use), the motor, the battery case, the cap with switch, and the battery. If you're careful, the motor and battery holder with spring should come out still connected, but if not, re-connect the spring to the right-hand terminal, and hook the metal piece on the outside to the left-hand terminal.
3. Tape the motor and battery case together and insert battery into cap, positive end up.
4. Turn the switch to "On" and push cap and battery into motor assembly until you get good contact between the two metal pieces, as evidenced by strong vibration from the motor.
5. Tape the cap & switch in place, being sure to maintain a good connection. Turn off and set aside.
For kids 8 & under, I would do this part for them in advance, and just prep one as a demonstration so they can see what the parts are, where they came from, and how they work together, unless you have lots of adults to help. For older kids, part of the fun is taking something apart and turning it into something new, and part of the learning process is figuring out the connections and troubleshooting, so let them do it all themselves (allow a little extra time).
Instead of removing the motor and additional circuit components from the toothbrushes, leave them in, and simply cut off the toothbrush head, leaving everything nice and cozy inside the handle so that connections can't loosen. I used a bandsaw, but you could use a handsaw or heavy duty snipers as well. Be sure to at least show the kids what the whole motor assembly looks like and how it works.
Next, take a 4-1/2" piece of pool noodle and use 2 or 3 rubber bands to attach 3-4 markers as legs [you can later experiment with the number of legs, placement, and length to see how it affects the patterns your bot draws]. If desired, the markers may be taped or hot glued permanently in place, or left with rubber bands so they can be changed.
Now, get creative and decorate your bots using whatever random arts and crafts supplies you have! One note of caution: resist the urge to over-decorate, or your bot may end up being too heavy to move. Pipe cleaners are great to make arms, antennae, glasses, or coils, and can be stuck right into the foam.
After the bots are decorated and all the glue has dried, it's time to test them out. Cover a large table or floor with paper, take the caps off the markers, turn the motor on, insert into the center of the pool noodle, and turn it loose! See how each one will draw in a slightly different pattern, and that patterns will change when the marker positions are changed even slightly.
(This one is a "peacock from Hawaii")
(The video below was accidentally shot in slo-mo)
Leftover toothbrush heads can be used for cleaning, spatter painting or bristlebots (I have not tried these yet.)
There is always the possibility of a dud motor or dead battery [though out of 24 toothbrushes and batteries, we didn't have any duds], so it's a good idea to buy a few extra, and test the toothbrushes to see if they work before continuing.
The most likely problem you will run into is loose connections. If your motor seems to be weak, or it stops working after previously working well for a short time, it is almost certain to be a loose connection, usually where the metal piece from the battery holder connects with the metal piece from the cap/switch. Remove the tape and see if you can push the two pieces back together to get good contact and regain motor function. If so, re-tape while holding it in that position. You may have to repeat this. If this doesn't work, double-check the connection to the motor itself, and if that doesn't work, try changing the battery.
Other issues may require adjustment of the marker positions and attaching them more securely if they are slipping too much, or trying glossier paper.
How It Went
The only problem we had was with loose connections due to the electrical tape stretching and loosening after I had pre-assembled all the motors a few days earlier. I am going to have to play around and try to prevent that by using different tapes, or maybe even a couple of dots of hot glue in addition to taping [I also might try just cutting the toothbrush heads off and retaining the handle as a case to keep everything together]. It required some scrambling and re-taping during the program, but the kids were all good sports and didn't get frustrated (though I might have a little!). Other than that, the program was a hit!
We had 10 kids, ranging in age from 5 to 12. I started the program by reading Robo-Sauce by Adam Rubin and Daniel Salmieri, a fun story about a boy pretending to be a robot, then using a secret formula to turn himself, everyone else, and even the book into robots! They all seemed to like the story and thought it was neat how the book had a hidden cover folded into it that transformed it into a robot book.
The kids seemed to really like all parts of the program: the story, decorating their bots, and the bots themselves. Some of them really got into the decorating! I really liked how this program had technology and art both, allowing them creativity in decorating their DoodleBots, and the art that their Bots created. Several of them asked if we would come back next week and do it again, and said it was the best program ever! I even got a couple of hugs, which I didn't really expect from school-aged kids.
This was my first school-aged program, and my first STEAM program, and I was very happy with how it went, and I plan to do it again with another group, once I get the loosening-tape issue worked out (and stock up on more toothbrushes!).