Thin Film Actuator Powered Microbots: Morph, Lock Shape, and Operate Tetherlessly

A robotics team from Tsinghua University in China, in collaboration with three colleagues from Beihang University, has developed a novel type of miniature robot. This robot is capable of continuously altering its shape and "locking" into specific configurations. In their paper published in the journal Nature Machine Intelligence, the research group provides detailed insights into the design elements, capabilities, and potential applications of this tiny machine.

The core of this new miniature robot lies in the thin-film small actuator developed by the team. The actuator is made by spinning a silicone coating onto a silicon wafer, followed by transferring a polyimide film onto the substrate. Then, a layer of copper is added through electron beam evaporation, photolithography, and wet etching of the copper layer, with final touches completed using laser cutting.

By integrating sensors, motors, and Lego-like blocks, the actuator can assemble robots with transformation abilities. The final robot measures just nine centimeters in length and weighs 25 grams. Researchers claim it is currently the smallest untethered robot capable of operating on land or in the air.

The researchers note that this micro-robot can operate without any tether and transform into various forms, ranging from a rolling vehicle (able to move at 1.6 meters per second) to a flying drone. The team even built a version that can perform both functions simultaneously. The design concept focuses on creating small robots that can morph on demand and lock into configurations required for specific tasks.

The research team suggests that their design could lead to the creation of nearly limitless types of micro-robots. They have already constructed prototypes capable of rolling, walking, running, jumping, climbing, and even flying. They point out that these tiny machines bear similarities to the robots seen in the movie Transformers.

Finally, the team proposes that their robots could serve multiple purposes, such as toys or tools for children’s educational projects. They also highlight possible commercial applications, including biological research in confined spaces like insect nests—or, like many small robots, they could assist in search-and-rescue operations.