Engineering students will demonstrate inventions and show how technologies work -- such as the sensor that activates a car's air-bag system -- during the University of Colorado at Boulder's ITL Fall Design Expo on Dec. 3. The event, which is free and open to the public from 1 p.m. to 3 p.m., will be at the Integrated Teaching and Learning (ITL) Laboratory, located on Regent Drive one block south of Colorado Avenue.