A fish-inspired robot that can travel 26 meters through the air after takeoff could be used to collect water samples in hazardous and cluttered environments, such as during flooding or when monitoring ocean pollution. Robots that can transition from water to air are desirable in these situations but the launch requires a lot of power, which has been difficult to achieve in small robots.

The new system requires just 0.2 grams of calcium carbide powder in a combustion chamber. The only moving part is a small pump that brings in water from the environment in which the robot sits such as a lake or ocean. The water and the calcium-carbide powder then combine in a reaction chamber, producing a burnable acetylene gas. As the gas ignites and expands, it pushes the water out as a jet, which propels the robot clear of the water and into a glide of up to 26 m.

The robot was tested in a lab, in a lake, and in a wave tank, showing that it can escape from the water’s surface even under relatively rough conditions. While similar robots often require calm conditions to leap from the water, the new robot generates a force 25 times the robot’s weight, giving it a greater chance of overcoming the waves.

The robot, which weighs 160 grams, can jump multiple times after refilling its water tank. This could allow it to float on water and take samples at multiple points without additional power, saving energy over longer distances compared to an electrically powered robot.

The team is working to build new vehicles using advanced materials and begin field trials of the robot in a range of environments including monitoring the oceans around coral reefs and off shore energy platforms. The low-power, tether-free robots could be used in environments that are normally time-and resource-intensive to monitor such as after floods or nuclear accidents.

For more information, contact Hayley Dunning at This email address is being protected from spambots. You need JavaScript enabled to view it.; +44 (0)2075942412.