Piezoelectric Outdoor Flooring System

Capstone Design Project

Fig 1. Rubber Mat Prototype

NASA’s Kennedy Space Center reached out to the Georgia Tech Research Institute (GTRI) to develop an outdoor  interactive user experience called the Vapor Trail. It would be a self-powered piezoelectric flooring system capable of tracking users and allowing them to interact with the exhibit. GTRI posed the initial design and proof of concept of this system as a senior design project, and my team was chosen to develop this flooring system based on our collective knowledge and experience. During this project, I was the leader in developing prototypes and the final design mock up, performing engineering analysis, drawing conclusions and foreseeing future endeavors.

Various prototypes were developed as stepping stones to the final design. We had to ensure the piezoelectric effect could still be observed after the load was distributed across the tile, and that the tiles were generating a usable signal. We first accomplished this with tiles made of rubber, then created a similar prototype made of ultra high performance concrete. Engineering analyses, including static forces analysis, fatigue analysis of columns, and finite element analysis (FEA) all served to optimize our design and help develop the final

Fig 2. Ultra-high-performance Concrete Prototype

prototype.

I also designed experiments to test the real-life properties of the prototypes. A piston actuated at a standardized force was used to verify the prototypes could generate enough voltage output to power an RFID chip, a device with the tracking technology necessary for the final flooring system. The rubber tile succeeded, while the concrete tile did not. However, the rubber tile did not have the performance capabilities of ultra-high performance concrete. We decided to combine the two prototypes in the final design.

Fig 3. Experimental Setup

Fig 4. Rubber Tile Response

Fig 5. Final Design Response
Fig 6. Final Design

The final tile at this stage in development was a piezoelectric circuit sandwiched between a thick frame of high density polymer and a thin acrylic insert. The thin acrylic would allow the transfer of vibrations, like the rubber tile, guaranteeing sufficient voltage output, and the high density polymer would maintain the structural integrity of the tile, like the high performance concrete tile.