When a family of four was recently caught in a current off Rockaway Beach, Ore., an aquatic drone made from advanced composite materials saved the day. Without access to rescue swimmers, jet skis or helicopters, the local fire department deployed the Emergency Integrated Lifesaving Lanyard (EMILY) developed by Hydronalix. “They rescued an uncle, aunt and two kids within minutes and prevented them drowning,” says Anthony Mulligan, founder and CEO of Hydronalix.
EMILY can be launched from beach, boat, bridge or helicopter and guided via radio control through surf and debris to reach potential drowning victims within seconds. Victims then hold onto the aquatic drone’s perimeter lifeline until help arrives or they are pulled to safety by an attached rope. Each EMILY drone can support up to 10 people at once or tow a raft to rescue larger groups as it has done during Indonesian ferry accidents. More than 400 of Hydronalix’s aquatic drones are in use in 22 countries and deployed on a rescue mission an average of 1½ times a day, says Mulligan.
The story of EMILY begins with Mulligan’s 20 years as founder and CEO of Advanced Ceramics Research, which specialized in ceramic composites for a variety of applications, including unmanned air vehicles (UAVs) used by the U.S. armed services during the Gulf War. After selling the company in 2009, Mulligan founded Hydronalix to build aquatic drones with the same advanced materials as UAVs. The company built its first drone for the National Oceanic and Hemispheric Organization in 2010.
Shortly thereafter, Mulligan and his business partner, Robert Lautrup, launched a drone off Malibu Beach, Calif., during the remnants of a hurricane just to see how it would hold up. “No matter how bad the wave was, the drone would always go through it,” Mulligan recalls. “We got the idea that if we put a float on it, it could go out and rescue anyone that was in trouble.”
At 50 inches long, 15 inches wide and 15 inches high, EMILY is “a showcase of advanced composite materials,” says Mulligan. The aquatic drone, built much like a small boat, features an epoxy resin reinforced with fiberglass, carbon fiber, Kevlar® fibers and ceramic fibers. The hull is fabricated in two pieces using aluminum molds and wet lay-up of various woven fabrics and fiber orientations determined through computer modeling. To allow the drone to survive impact with rocks, reefs, debris and extreme waves, the outer edges of the hull are reinforced with 2,000 Kevlar fiber tows coated for maritime use and the keel contains three layers of Kevlar. Once cured, the upper and lower parts are laminated together within minutes to maximize strength. For special applications, such as deployment from a high-altitude aircraft, the hull can be constructed in a single piece using water soluble molds.
EMILY can travel up to 38 mph. Its motor is connected to a multi-angle CFRP shaft with circumferential edges designed for tensile strength and leading edges reinforced with nanoplatelet reinforced nylon for maximum resistance to damage by debris. Mulligan says a CFRP shaft is key because it returns to its original shape after flexing on impact – for example, when EMILY is dropped off a helicopter or bridge or deployed in rough waters – making it highly durable.
