The most prevalent pollutant in beachfront ecosystems is microplastic. Microplastics are the broken-down remains of discarded plastic products that are less than 5mm in diameter, and they can be found in large numbers in the top three inches of sand. Animals that inhabit burrows in the sand, as well as sea life, are affected by this plastic due to accidental ingestion. Project Thetis is constructing an autonomous robot that is capable of driving over the dry sand on the beach to collect these microplastics. We will prioritize the preservation of the ecosystems we involve ourselves in, so the robot will have as little impact on the topography of the sand as possible. The methodology for achieving our goals is to separate sand and plastics based on their unique terminal velocities. Sand has a lower terminal velocity than the average microplastic, so the air will be moving at a higher velocity than the sand carrying it upward. The velocity of the air will in turn also be less than the terminal velocity of microplastics, allowing the microplastics to fall into a collection bin. Future goals for the project involve utilizing the microplastics collected to make 3D printing filament to reuse material and prevent it from reverting back to what it is currently: microplastic.