A research team from Tsinghua University in China has developed the world’s smallest and lightest untethered terrestrial-aerial microrobot. Weighing just 25 grams and measuring 9 centimeters in length, this futuristic robot doesn’t just walk or fly—it morphs.
Described by its creators as a “Transformer-like” microrobot, the robot can perform on both land and in the air, reaching speeds up to 1.6 meters per second on the ground. Central to its performance is a groundbreaking thin-film-shaped actuator—a miniature powerhouse that enables the robot to morph its structure and lock into various shapes on demand.
“The actuator is the ‘heart’ of the robot,” said Professor Zhang Yihui, lead researcher and professor at the School of Aerospace Engineering and the State Key Laboratory of Flexible Electronics Technology. This actuator, despite being only a few millimeters in size, is engineered for continuous shape morphing and locking, a capability most actuators under 5 cm currently lack.
The Tsinghua team leveraged a Lego-like modular design strategy, integrating actuators, rotors, motors, a control module, and a lithium battery into a highly compact frame. When flying, its components operate as rotors, and when grounded, those same rotors cleverly fold into wheels thanks to the shape-shifting actuator.
But the brilliance doesn’t stop with locomotion. The research also introduced a 4.5 cm tall miniature “Transformer” robot weighing just 0.8 grams, made using over ten actuators. According to Zhang, these robots can walk, run, jump, fly, climb, and more—expanding their use cases drastically.
Beyond traditional robotic uses, the implications of the actuator are multidisciplinary. From wirelessly controlled microrobots capable of diagnosing faults in hard-to-reach equipment, to implantable medical devices like shape-morphing vascular stents, this technology offers vast promise. It can also be applied to bioelectronic devices, as well as haptic feedback systems for VR and AR applications, creating immersive and responsive user experiences.
“The new actuator can be electrically controlled to continuously deform into any desired shape and then ‘lock’ that shape,” Zhang explained. “This kind of functionality was previously extremely difficult to achieve in such a small form.”
Published in Nature Machine Intelligence, the research represents not just a technological feat, but a reimagination of how robots can interact with, adapt to, and eventually enhance the environments we find challenging—or even deadly.
