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surface tension
This tiny robot can jump from water without making a splash
It’s able to exert force of up to 16 times its own body weight without breaking the water.
A TEAM OF researchers from Seoul National University and Harvard have created a tiny robot that can jump on water.
The tiny stick robot is able to mimic a water strider’s ability to jump from a solid surface or water with the same power and height.
To recreate the same action, the researchers collected water spiders and captured videos of their movements, analysing the mechanics that allow them to skim on and jump off the water’s surface.
They found that a water spider’s legs have slightly curved tips and so is able to take off from the water’s surface by rotating the curved tips of their legs inward.
To make sure their robot was able to do the same, they found the best way for it to jump was to maintain leg contact on the water for as long as possible during the jump motion.
By mimicking this, the robot built by the team can exert force up to 16 times its own body weight without breaking the water’s surface. One of the co-authors of the study, Robert Wood said the reason it was able to do this was because it spread out the push needed to jump.
If you apply as much force as quickly as possible on water, the limbs will break through the surface and you won’t get anywhere… The resulting robotic insects can achieve the same momentum and height that could be generated during a rapid jump on firm ground – but instead can do so on water – by spreading out the jumping thrust over a longer amount of time and in sustaining prolonged contact with the water’s surface.
The robot was created by manufacturing folded composite structures that self-assemble, allowing them to create small machines. The research team said such robots could be used to carry out actions like monitoring pollution in waterways but stated their goal wasn’t to commercialise their findings.
Details of the team’s research was published in the journal Science.
Wyss Institute / Vimeo
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