Students are presented with a real-life problem as a challenge to investigate, research and solve. Specifically, they are asked to investigate why salt water helps a sore throat, and how engineers apply this understanding to solve other problems. Students read a medical journal article and listen to an audio talk by Dr. Z. L. Wang to learn more about quantum dots. After students reflect and respond to the challenge question, they conduct the associated activity to perform journaling and brainstorming.