Uni of Bristol scientists develop tiny robot fish which could help underwater exploration

Researchers from the University of Bristol have developed a brand-new 'robot fish' which is said could make underwater exploration more accessible in the future.

According to a brand-new study, the device, which is fitted with a special twisted and coiled polymer (TCP), works like a muscle does to drive it forward.

When it's exposed to heat, the low-cost and lightweight device contracts like muscles - converting the energy it absorbs into a form of mechanical motion.

It works through a process known as 'Joule heating'.

The robot is 224mm long including a 30mm long caudal fin, and weighs 49.7g with the float.

Lead author Tsam Lung You from Bristol's department of engineering mathematics said: "Twisted and coiled polymer (TCP) actuator is a promising novel actuator, exhibiting attractive properties of lightweight, low-cost high energy density and simple fabrication process.

"They can be made from very easily accessible materials such as a fishing line and they contract and provide linear actuation when heated up.

"However, because of the time needed for heat dissipation during the relaxation phase, this makes them slow."

"Our robotic fish swam at the fastest actuation frequency found in a real TCP application and also the highest locomotion speed of a TCP application so far.

"This is really exciting as it opens up more opportunities of TCP application in different areas."

The researchers' findings have been published at the 6th IEEE-RAS International Conference on Soft Robotics.

So far, the TCP devices have mostly been used for things like wearables and robotic hands, but researchers claim these new findings open up the possibility for marine exploration.