The scientists applied electrical charges to manipulate liquid metal, using pulses and movement of droplets to create a new type of tactile feedback.

They also used the system to form the metal into 2D shapes such as letters and logos. As shown in the images below, these can either be large droplets of metal that are morphed into patterns, or smaller drops that are animated to create similar effects.

A large droplet of liquid metal morphs into the letter S using programmable electrical charges.

A single drop moves to animate a similar S shape.

The team says the findings represent an “extremely promising” new class of materials that can be programmed to seamlessly change shape. This opens up new possibilities in “soft robotics” and “shape-changing mobile devices”, the researchers say.

While the invention might bring to mind the film Terminator 2, in which the villain morphs out of a pool of liquid metal, the creation of 3D shapes is still some way off. More immediate applications could include mobile devices with fluid elements, and reprogrammable circuit boards.

Dr Simon Robinson, a Research Officer collaborating on this work in the College of Science at Swansea University, said: “This is a new class of programmable materials which can be dynamically controlled to transform their shape and motion. We are particularly excited about the potential for future mobile devices whose cases can gently tap your finger, or stroke your hand to give feedback.”

The electric fields used to control the liquid are created by a computer, meaning that the position, shape and animation of the liquid metal can be programmed and controlled dynamically.

Professor Sriram Subramanian, head of the INTERACT Lab at the University of Sussex, who collaborated on the work, said: “Liquid metals are an extremely promising class of materials for deformable applications; their unique properties include voltage-controlled surface tension, high liquid-state conductivity and liquid-solid phase transition at room temperature.

“One of the long-term visions of us and many other researchers is to change the physical shape, appearance and functionality of any object through digital control to create intelligent, dexterous and useful objects that exceed the functionality of any current display or robot.”

The research was presented recently at the ACM Interactive Surfaces and Spaces 2017 conference in Brighton, and the ACM Symposium on User Interface Software and Technology in Québec City.

This is a joint project between Swansea and Sussex funded by EPSRC on “Breaking the Glass: Multimodal, Malleable Interactive Mobile surfaces for Hands-In Interactions” (EP/N013948/1).

• For more information about the College of Science at Swansea University go to http://www.swansea.ac.uk/science/