Don’t sweat it: Technique developed to help robots cool off

The cooling powers of sweat could soon be used to help over-heated robots let off some steam like humans.

As robotic technology advances and machines begin to carry out more demanding tasks, the heat they generate is likely to increase, running the risk of malfunctioning if not cooled down.

This has led scientists from Cornell University to develop a technique to allow machines to “sweat” off cooling liquid stored around actuators, the component responsible for moving and controlling a mechanism or system.

“To thermal regulate, engineered systems often have dedicated components – our laptops have fans, cars have radiators, unfortunately there’s a penalty to these strategies,” said Thomas J Wallin, a research scientist at Facebook reality lab, who worked on the project.

“The cooling components take up valuable space inside our electronics and they add weight.

“Additionally these components are conventionally made from rigid materials that are incompatible with fully soft robots.

“So to realise the numerous advantages of soft robots, we wanted to explore a thermo regulatory strategy that was compatible with soft polymeric materials.”

Robot sweating technique
Robot sweating technique

The finger-like fluidic actuators are made of hydrogels, a type of material that can hold a large amount of water and act as heat reservoirs.

Each of these fingers feature a bottom layer with an internal channel for water flow and a top layer dotted with micropores.

At low temperatures below 30C, the pores remained closed.

But when the temperature rises, the top layer expands, dilating the pores and allowing pressurised fluid from the bottom layer to “sweat” out of the pores.

In testing, presented in the Science Robotics journal, the sweating actuators cooled off about six times faster than their non-sweating counterparts when exposed to wind from a fan.

However, scientists behind the technique admit there is still work to do before robots can break out into a sweat anytime soon.

Sweating efficiency temporarily dampened the robot’s ability to move, they said, and are yet to find a way to replenish water lost during extended operation.