I've Got an Idea
Forsyth sixth graders immerse themselves in a yearlong study of the human body in science. To extend the study of cells in science class, sixth graders learned more about cell membranes through an engineering unit from the Engineering is Elementary program. Forsyth’s Morgan Engineering & Science Fund provides the resources necessary for students in Grades 2-6 to engage in a yearly unit of study in engineering. Each unit presents a real-world problem or opportunity for which particular kinds of engineering will be critical. The cell membrane model challenge is the Grade 6 engineering unit.
“I’ve got an idea,” was a recurrent refrain. There was a lot of discussion between the sixth grade scientists and their teacher: “Mrs. Deken, what do you think about . . . ?” As they worked in teams, side-by-side in the Grade 6 science lab, the kids were focused, creative, tenacious, thoughtful, and completely engaged.
WHAT DID THEY DO?
Objective: Working in teams of two, design a cell membrane model that will retain 1/4 cup of water after 24 hours when 1/2 cup is poured over, so that 1/4 cup water drains through and remains in the container.
1. Research: Research properties of water absorption to see which materials retain water and for how long and which materials allow water to pass through and at what rate to determine what combination of materials would produce the most effective cell membrane.
2. Design/Build: Write up the plan with an illustration of the model concept. Build a model cell membrane using materials such as coffee filters, sponge, aluminum foil, cleaning wipes, etc. There are restrictions on amounts of some of these materials.
3. Test: Pour 1/2 cup of water over each model. Wait 24 hours and measure the amount of water retained in container. The goal is 1/4 cup or 2 ounces of water in the container.
4. Results: Which of the 21 models were successful? Some had no water in the container, some too much, 2 models were spot on with 2 ounces exactly, and 5 were within 10 milliliters or less of the goal. The final step is a written analysis of results: what would you do differently? “Nothing,” from some teams, and others had to re-think their design.
The impressive thing about the results is that the experiments were done independently. Mrs. Deken was available for discussion, but if she knew the successful formula (not likely), she gave no hints about what works. This is the first and only time the sixth graders have done this engineering challenge, and one third of the models were successful.