China has built a robot arm trio to do maintenance work for future fusion reactors. Cracking fusion energy would mean cheaper, virtually limitless clean energy and a decarbonized global economy.

The trio, described as a "remote-handling test platform," was designed for the country's Comprehensive Research Facility for Fusion Technology (CRAFT) and built under the lead of the Institute of Plasma Physics, Chinese Academy of Sciences. It passed the final evaluation on Tuesday.

It can operate in extreme environments with intense radiation, powerful magnetic fields and high heat.

Core components of a fusion reactor, like the cladding and divertor, are under constant stress from these extreme conditions and need to be repaired remotely by robots instead of humans. However, current industrial robots are not built to withstand such harsh environments while also carrying heavy loads with high precision.

These new arms were specifically developed to solve this problem, paving the way for the stable operation and future commercialization of fusion energy, which has the potential to provide a borderline infinite amount of electricity for human beings.

The evaluation showed that the giant main arm can handle an incredible 60-tonne payload with exceptional precision, achieving a positioning accuracy of ±3.1 millimeters and a vertical lifting accuracy of ±3.8 millimeters.

The two smaller arms can repeatedly return to a precise spot with an accuracy of ±0.01 millimeters. This makes it the most advanced remote-handling system of its kind in the fusion field.

The technology behind these new robot arms is also versatile. It can be applied to other demanding fields, such as nuclear power inspection, aerospace and heavy-equipment operations.