One of the goals of the activity is to help students learn how to recognize ‘smart paper’ in their daily lives and help students recognize hidden technologies embedded in simple things. Students will be guided through hands on interaction with carbonless and thermal paper. Concepts that are introduced in the activity are the function and use of microcapsules, accomplished by drawing analogies to larger capsules: medicines, paint balls, M&M’s etc. We’ll show and discuss different ways to break capsules (heat, pressure, and dissolution). We will brainstorm uses for capsules and how they are applied to and specially designed for use in “smart paper”. The topic of chemical reactions is also presented, with an emphasis on the reaction that occurs when the microcapsules rupture and subsequently develop color. Each student will conduct a safe experiment, under supervision, that evolves color from an invisible ink. The experiment stresses the connection to the smart papers discussed.
Full Instructions
Teacher’s Guide: Materials and where to find them
Handout: Worksheet
Instructions for making cabbage juice (link)
Materials
- Carbonless copy paper (enough for each student to have a ~2″ x 2″ square)
- Pen/pencil
- Lemon juice and small container to hold lemon juice
- Absorbent paper (hand made paper is best, water color paper also works well)
- Cotton swabs (one per student)
- Newspaper or trays (to protect work space)
- Thermal paper (enough for each student to have an ~2″ x 2″ square)
- Heat source (iron or toaster)
- Bath beads (several, if splatter box is being utilized)
- Paintballs (several, if splatter box is being utilized)
- Paintball “splatter box” and weights (or Bubble wrap can be used to illustrate the same concepts)
- Red cabbage juice
- Spray bottle
- Computer paper
- Examples of thermal paper (receipts, airline tickets, concert tickets, lottery tickets)