Microrobots powered by thin-film actuator can morph, lock shapes and operate untethered

A team of roboticists at Tsinghua University, working with a trio of colleagues from Beihang University, all in China, has designed a new type of microrobot that can continuously transform its shape and “lock” into specific configurations. In their paper published in the journal Nature Machine Intelligence, the group describes the factors that went into their design, the capabilities of the microrobots and possible uses for them.

The key to the abilities of the new microrobots is the thin-film-shaped small-scale actuator the team developed—it was made by spinning a coating of silicone onto a silicon wafer and then transfer printing a polyimide film onto the substrate. That was followed by adding a layer of copper using electron beam evaporation, photolithography, and wet-etching of the copper layer. It was finished using laser cutting.

The actuator allows for building tiny robots with shape-shifting abilities when sensors, motors, and Lego-like blocks are added. The result is a robot just nine centimeters long and weighing 25 grams. The researchers claim it is the smallest untethered robot that can be run on land or through the air.

The researchers note that the resulting microrobots can be run without a tether and can assume a wide variety of shapes, from rolling vehicles (that can move along at speeds of up to 1.6 meters per second) to flying drones. The researchers even built one that can do both. The idea, they note, was to build tiny robots that could shape-shift on demand and then lock into the configuration desired for a particular use.

The research team suggests ideas for the types of microrobots that can be built using their design are nearly limitless, noting they have built prototypes that can roll, walk, run, jump up and down or, as a means of locomotion, climb and fly. They note that their tiny robots are similar in many ways to the robots seen in the Transformers movies.

The team concludes by suggesting their robots could be used in a variety of ways, as toys, or in research projects for children. They note there are likely commercial applications as well, including biology research in small venues, such as insect nests—or, like many small robots, they might find use in search and rescue operations.

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