Creating a prototype is an important part of the engineering process. Adding paper circuits and fans to a cardboard model can be a cost effective way for students to build a prototype. The Hen House Paper Circuit kit contains copper tape, white LEDs, 3-volt coin cell batteries, hobby motors and propellers. Enough materials for 12 small groups of students.
Add complexity to the prototype by using an Arduino board to control the lights and fan. The SparkFun Inventors Kit or Arduino Starter Kit is a great way to get started with Arduino. If you aren't ready to invest in the hardware Tinkercad.com is a virtual way to learn the basics.
Are you looking for a more basic kit with colorful LEDs? Check out the Paper Circuits kit.