Adapted by Lenore Kop from the workshop "Kid's Engineering", Oregon Museum
of Science and Industry
Type of Entry:
Type of Activity:
- Hands-on activity
Jumpy Doll construction is a culminating activity in a unit on the muscular system. Students are challenged to design and construct a jointed figure that moves in a motion something like jumping jacks when a string is pulled.
Although most of the Human Physiology students in my class are seniors, they are not necessarily college-bound. It is very heterogeneous; some are in honors/AP courses, while others still have difficulty with English as a Second Language. In addition, it has never been gender-balanced. There are usually 2-4 males, and 15-29 females. With all this in mind, I try to develop activities that go beyond the cookbook and challenge students to problem solve as well as tie in physiology concepts.
The "Jumpy Doll" is a jointed figure that moves its arms, legs, etc. when a string is pulled. I use this project as a model of muscle/bone movement. The action of pulling the string represents the prime mover muscle contracting. The body part that moves is the bone. The place where the string attaches to the moving body part is analogous to the muscle's insertion. (What would represent the origin?) A problem with using this as a model is it does not accurately show the way muscles work in groups. In nature gravity, not a second muscle "string", enhances the action of the antagonist which brings the body part back to its original position.
The project was introduced by showing a jumpy doll I had made in a workshop, but you could use a purchased one. After observing the doll move, students hypothesized how it worked by describing/sketching what they thought the interior looked like. Then they were challenged to create their own doll. No patterns or directions on how to make the doll was provided -- that was part of the problem-solving aspect. I intended to leave the sample out for examination (when making my own, I had to study the example several times myself), but since it got broken on the first day, I put it away and the students had to rely on their creativity.
Some of the problems were in design: What to make? What part - wing, tail, leg, mouth - could move? (Remembering to cut the moving part as a separate piece was a problem for some!) Where should the joint be positioned, and where should the string be attached to get the desired motion? How can friction be reduced at the joint so the moving part does not get stuck?
Other problems dealt with construction: How do you cut the cardboard? (I provided cardboard that was a little too thick for the razor, but it was not on purpose!) What material would make the best joints? How is a glue gun used? How should the front be attached to the back without gluing the moving parts or string in the process?
While it took a lot of class time (1.5 weeks), I chose to do it in class because I wanted the students to be able to talk with and observe each other, and also to be sure it did not become a parental project. Initially, there was a lot of frustration as indicated by the problems above. Sometimes I made outright suggestions, but for the most part they figured it out among themselves or asked to bounce ideas off of me. Because there were no patterns or procedures, they eventually showed more understanding about the jumpy doll's construction and how it relates to their own body. There was also a real sense of pride when a classmate pulled the string, and it WORKED!
This part really depends on what you want to make available. The following is what I provided, but students were also free to bring materials from home.
- base - cardboard
- joints - barbecue skewers, straws, tubing (air)
- low temperature glue guns and white glue
- decorations: construction paper, pens, crayons, paint
- tools: scissors, razors, dissecting needles, hole punchers, cork borers
For this project, you may work by yourself, or with a partner. Your challenge is to create a jumpy doll that exhibits at least 3 joints that produce movement with a single pull on a string.
- No pattern will be provided, nor directions as to how to make the joints, or where to place the insertion points, etc. This is part of the challenge.
- You are allowed to examine the sample jumpy dolls but you are free to select the shape of your doll and the way you design the joints.
You may bring materials from home as well as use what is available in the classroom.
- Observe the jumpy doll shown. Sketch its basic shape in your journal, and how you think the movement is occurring.
- Using the materials available, the sample provided and your imagination, create a jumpy doll.
- Journal Entries:
Each day you need to record how you utilized your class time, describe any problems you encountered and how you went about solving that problem (or plan to solve it). In addition, you may be asked to address a focus question for that day.
The scoring of this project will be based on the following criteria:
Design (20 points possible; 4 bonus):
4 - doll incomplete; not functional
8 - has at least one joint; works but not all the time
12 - has at least two joints; works most of the time
16 - has at least three joints; works most of the time or positions are not quite in place (ie. insertions not well positioned)
20 - has at least 3 well functioning joints; movements look appropriate
4 extra points - doll exhibits two different movements with a single pull (example will be shown but not left out)
Appearance (10 points possible)
2 - unfinished, not decorated, plain cardboard
5 - partly completed
7 - completed but not visually appealing (ie. messy)
10 - fully completed and visually appealing
Journal (10 points possible)