A drone that distributes liquid foam to fix pipeline leaks could eliminate the human danger and the logistical difficulty of such repairs where the infrastructure is located remotely.

"Buildrone," an unmanned aerial vehicle (UAV) with such functionality built by a team from Imperial College London's Aerial Robotics Laboratory has taken home the top award at the UAE Drones for Good competition in Dubai over more than 1,000 other entries. The UAV was developed under the supervision of the lab's director, Dr. Mirko Kovac.

Dr. Mirko Kovac, director, Aerial Robotics Laboratory (l) and Talib Alhinai, PhD candidate. Image credit: Imperial College London.Current technology in this arena limits drones to taking only sensor readings. By adding a mechanism that can distribute polyurethane foam in liquid form mid-flight, Buildrone is able to effectively repair potentially dangerous leaks on-site and in real time, without risk to its human operators.

The drone consists of a quadrotor configuration with two integrated payload packages: a mechanism to deposit the foam and an onboard-decoupled manipulator delta-arm to balance the drone while it is hovering. The deposition mechanism stores two-component polyurethane foam in separate chambers onboard to ensure they are in a nonreactive state.

A linear actuator is used to control the release of the two components, after which mixing and reacting take place within a buffer chamber before the fluid is deposited through a vertical nozzle. The delta-arm manipulator enables the dispensing mechanism to patch the leak with high precision. Once the foam is applied on the intended site, it takes less than five minutes to fully expand upon contact with air (up to 25 times its original volume), allowing effective sealing of the intended area.

The industrial applications for this technology are potentially vast and include oil, gas, chemical and water pipelines.