Sheldon Cooper would had loved it.

Seven teams of Gwinnett County Public Schools students showed off their science experiments for a panel of local investors and academics in a “Shark Tank”-style competition at the school district’s science fair Friday at the Infinite Energy Center. The experiments included an app that examines skin for possible signs of melanoma, a drone that can carry items from hazardous-material sites and a plan to create a near completely sustainable apartment building.

The competition, officially called the Innovation In Action Expo, was the first of its kind at the fair. In some cases, the students wanted money to continue their work. Most of them wanted mentoring and advice about how to improve their projects. The judges are scheduled to provide feedback to the students this week.

In all, nearly 900 students from all grade levels participated in the fair. The projects included a security system and a self-brushing toothbrush. Jonathon Wetherington, the school district’s science director, said the goal of this year’s science fair was to apply math in their work and create projects that make a difference in their community.