Teach students about tensile structures by building 3-dimensional bubble wands. Tensile structures are formed when a material or cable is stretched and held in tension between two or more anchors, such as suspension bridges or shade sails. With tensile bubbles, students will observe how tensile structures are formed as the bubble solution is stretched both between the rigid edges of the wand and the joints that form in the bubble solution itself.

Materials:

• Straight, multicolored drinking straws
• Pipe cleaners
• Bubble solution
• Tall plastic container

Instructions:

To create the pyramid (tetrahedron) bubble wand:

• Cut the straws. First cut each straw in half, and then cut in half again. You will get 4 straw sections from each straw.
• Thread a pipe cleaner through one straw and bend the end of the pipe cleaner to secure it at the end.
• Thread two more straws onto the pipe cleaner.
• Bend the long end of the pipe cleaner back to meet the starting point and twist the two ends around each other.
• Add two more straw sections onto the end of the pipe cleaner.
• Thread the pipe cleaner through one of the adjacent straw sections.
• Add one more straw section and bend it back to one of the straw joints to form a pyramid.
• Thread the pipe cleaner through an adjacent straw section to secure everything in place. If desired, add a straight section of straw onto the end of the pipe cleaner to form a handle.

To create the cubic bubble wand:

• Cut the straws. First cut each straw in half, and then cut in half again. You will get 4 straw sections from each straw.
• Thread a pipe cleaner through one straw and bend the end of the pipe cleaner to secure it at the end.
• Thread three more straws onto the pipe cleaner.
• Bend the long end of the pipe cleaner back to meet the starting point and twist the two ends of the pipe cleaner around each other. You will now have a square shape.
• Add three more straw sections onto the end of the long pipe cleaner.
• Thread the pipe cleaner through one of the adjacent straw sections.
• Add two more straw sections.
• Bend the shape to form two sides of a cube and thread the end of the pipe cleaner through one of the straw sections on the edge of the cube.
• Repeat Step Eight to form another side to the cube.
• Add one final straw section to complete the cube. Thread the pipe cleaner through an adjacent straw section to secure the final shape. If desired, add a straight section of straw onto the end of the pipe cleaner to form a handle.

To make the bubbles:

• Pour the bubble solution into the plastic container.
• Carefully dip the wand into the solution and lift the wand out of the solution SLOWLY.
• Students should see a multi-faceted bubble!