Researchers have developed a sub-millimetre-sized robot capable of sensing its environment, making decisions, and acting autonomously, marking a significant step forward in the field of microscopic robotics and bringing futuristic medical applications closer to reality.
In a study published in Science Robotics, scientists from the University of Pennsylvania and the University of Michigan revealed that they have built a programmable robot smaller than a grain of rice, equipped with onboard computing power and sensors. Unlike previous microrobots, which relied heavily on external control systems such as magnets or lasers, this new robot can operate independently in unfamiliar environments.
For decades, researchers have attempted to create microscopic robots for use in medicine, environmental monitoring, and manufacturing. However, progress has been limited by challenges related to power, control, and decision-making at such a small scale. Most existing microrobots require bulky external equipment and lack the ability to make autonomous choices.
The breakthrough came from integrating all essential components directly onto the robot’s body using Complementary Metal-Oxide-Semiconductor (CMOS) technology—the same manufacturing process used to produce computer chips. This approach allows hundreds of microrobots to be fabricated simultaneously on a single chip, significantly reducing cost and complexity.
Each robot measures between 210 and 270 micrometres wide and includes tightly integrated systems such as photovoltaic cells for power, a processor, temperature sensors, and movement actuators. The robots harvest light from external LEDs to power their operations.
To demonstrate autonomous behaviour, the researchers tested the robot in a fluid-filled dish with a temperature gradient—cool at one end and warm at the other. Using its onboard temperature sensor, the robot adjusted its movements in real time: it searched for warmer areas when conditions cooled and remained in place when optimal temperatures were detected. Across 56 trials, the robots successfully modified their movements without any external commands.
According to the research team, onboard computing and digital programming allow a single microrobot to be reconfigured for multiple tasks after fabrication. By eliminating the need for complex external control systems, the technology could enable low-cost, large-scale deployment of microrobots.
While the development represents a major advance, researchers note that further work is required before such robots can be used inside the human body. One of the next goals is to create a fully wireless locomotion system that does not depend on external light sources.
If successful, these microscopic robots could one day be used for targeted medical treatments, internal repairs, environmental sensing, and precision manufacturing, opening new possibilities in science and healthcare.
