A Design Challenge Stemming from a Tiny Bead
For students in Mrs. Abraham and Mrs. Ricker’s first-grade classes, a mysterious bead recently became the starting point for a STEM design challenge.
One morning, Mrs. Abraham and Mrs. Ricker presented each of their first graders with bracelets made from white beads on a string. “These bracelets seem to be very plain,” explained Mrs. Abraham, “except they become very brightly colored when they are exposed to one thing.” The students’ job that day was to learn what caused the beads to reveal their secret coloring.
As the day went on, students tested a number of hypotheses. Some students thought that maybe it was light: if the beads were in the dark, maybe they would change colors. Once students got outside with their mystery bracelets, they started to notice that the colors on their beads were changing. Why? Some students thought it was because of the shade - if we go in the shade, they don’t change. Some students thought it was the temperature, so they tried to put their beads in the snow or warm them up to see if there was a change.
The first graders continued to test their guesses and some even took their bracelets home overnight, but students couldn’t come to a consensus of what was causing the color change.
The next morning, the class revisited the scientific mystery. Mrs. Abraham explained what was happening. It was sunlight - and more specifically, ultraviolet light - that caused the beads to change. The conversation changed to what UV light was and how our bodies react to it. They discussed why it was important to protect your skin from the sun.
“We took the bracelets outside that morning and it was a particularly cloudy day,” recalls Mrs. Abraham. “Even with the overcast sky, UV rays were present and the beads changed.”
As the class explored UV light’s benefits and risks, the lesson segued into a design challenge related to the class’s cross-curricular study of shelters. They were asked to create a shelter that shielded a critter (of their imagination) from too much of the sun’s dangerous UV rays.
- To begin the design challenge, students made little critters out of pipe cleaners, including some of the photosensitive beads that they investigated the day before. The beads would allow them to see whether their designs were effective at blocking UV rays.
- Students were given boxes, cardboard tubes, masking tape, paper cups and plates, foil, saran wrap, and cardstock. With a constraint that you had to be able to see their critter within the shelter, the first graders got to work building structures.
- Using an agile design process, students created prototypes of shelters for their critters and tested them outside in the sun.
- Designs that needed improvements were revealed by the color-changing beads while successful prototypes resulted in monochromatic critter models.
“It was so exciting to watch first graders explore and test their engineering skills,” reflects Mrs. Abraham. “Each student put their own creative spin on their creatures and structures.”