ATMO: Aerially Transforming Morphobot

By Naomi Choe, Jonathan Li, Jason Peng

Technology Group; Fairbanks BEST Homeschool, AK

Image sourced from nature.com

Scientists at Caltech have developed a new robot called ATMO, or Aerially Transforming Morphobot, which can smoothly transition between drive and flight by transforming in mid-air. Most of the morphobot’s function and structure is similar to both drones and robocars. ATMO’s four rotors used for flight fold down so that the shrouds protecting the rotors become wheels for driving. It can safely land with its rotors folded down at an angle of around 70° to the horizontal, and its wheels start spinning before touchdown to begin driving immediately after contact with the ground. ATMO weighs around 5.5 kg; when flying, the dimensions of the robot are 16 cm tall by 65 cm wide, but when driving, the dimensions reach 33 cm tall and 30 cm wide. The internal systems of ATMO are an onboard 6S LiPo battery for power and an onboard computer paired with sensors to help it successfully switch from one mode to the other. 

How It Began

For many years, researchers and engineers at Caltech had been trying to solve the issue of smooth and safe transitions in flight. Inspired by the versatility of a bird’s wings while flying, avoiding obstacles, and landing, they wanted to make their morphobot replicate similar functions. After NASA’s Mars exploration rover Spirit got stuck in soft sand in 2009 because its wheels could not get enough traction to free itself, the researchers figured that such a problem could be solved by giving a rover the power of flight, and they took on the challenge of making a robot that could both fly and drive effectively. Combining the concepts of a helicopter and a rover, they created the groundbreaking Aerially Transforming Morphobot. 

What Makes It Special

Morphobots are unique because they repurpose their appendages for multiple tasks; in ATMO’s case, its rotors fold down and become wheels. Reusing its thrusters as wheels allows morphobots to be smaller and lighter than conventional robots that have separate rotors and wheels. Furthermore, a single DC motor controls the central gear that tilts all four thrusters up and down, making ATMO even more compact than other morphobots such as Caltech’s previous M4 robot, which had 12 motors controlling body posture. But the defining factor of ATMO is its ability to transform in midair to begin driving the second it makes contact with ground. A typical morphobot switches functions after landing on the ground, but the robot risks getting stuck while trying to morph in difficult terrain. So, ATMO’s capability to smoothly switch between flying and driving thus addresses and solves a major problem in the aerospace industry. 

In order to transform in midair, ATMO must fold its rotors down while continuing to fly, but changing the angles at which its thrusters shoot air at the ground causes turbulence. To deal with complex near-ground forces and remain stable while transforming, ATMO has a special control system. The algorithm for its control system uses a technique called model predictive control, which constantly predicts how the air will affect the morphobot with the data provided through its sensors. This allows the drone to quickly adapt to the constantly changing currents of air as its thrusters morph. 

Looking to the Future

A current issue for ATMO is the cost of the robot, which is currently around $25,000. The goal is to reduce this amount to approximately $5,000 in order to make this technology more accessible. In addition, the team also wants to develop a model with higher manipulation capabilities and autonomous decision making. Further testing is also needed to discover how well the robot’s transformation works in complex terrain with more variable conditions. Thus, ATMO is not finished; since its release in April 2025, the morphobot is still being continually refined and tested by Caltech researchers. 

The capability of ATMO’s mid-air transformation is radically changing aviation and space research and exploration by overcoming issues of rough terrain. Additionally, the special control algorithm allowing for several modes of transportation provides more versatility to robots and drones, allowing them to assist in disaster zones or in exploration without worrying about the effects of harsh terrain. 

References

Mannion, A. ATMO Drone Shifts Shape Mid-Flight for Perfect Landings. (2025, September 23). The American Society of Mechanical Engineers. https://www.asme.org/topics-resources/content/atmo-drone-shifts-shape-mid-flight-for-perfect-landings 

Mandralis, I., Nemovi, R., Ramezani, A., Murray, R. M., & Gharib, M. (2025). ATMO: an aerially transforming morphobot for dynamic ground-aerial transition. Communications Engineering, 4(1). https://doi.org/10.1038/s44172-025-00413-6

California Institute of Technology. Mid-Air Transformation Helps Flying, Rolling Robot to Transition Smoothly. (2025, May 28). https://www.caltech.edu/about/news/mid-air-transformation-helps-flying-rolling-robot-to-transition-smoothly