Capable of powering tiny circuits and sensors, this zinc-air battery operates independently, freeing micro-robots from solar dependence and enabling them to perform critical tasks such as drug delivery within the human body or detecting gas pipeline leaks.
MIT engineers have developed an ultra-small battery that could revolutionize the deployment of autonomous, cell-sized robots for medical applications, such as drug delivery within the human body, and other uses, including detecting gas pipeline leaks. This battery measures just 0.1 millimeters in length and 0.002 millimeters in thickness, about the size of a human hair. It operates by capturing oxygen from the air to oxidize zinc, producing a current of up to 1 volt—sufficient to power tiny circuits, sensors, or actuators.
The researchers are integrating robotic functions into the battery itself and beginning to combine these components into functional devices. Published in *Science Robotics*, the research was led by MIT Ph.D. candidate Ge Zhang and graduate student Sungyun Yang. Strano’s lab has been focused on creating tiny robots capable of sensing and interacting with their environment. A critical challenge in this field is ensuring that these micro-robots have enough power to operate autonomously.
Frees Micro-Robots from Solar Dependence
Previous attempts to power such devices relied on solar energy, which necessitated a constant light source. These “marionette” systems, powered externally, limited the robots’ autonomy. The introduction of an embedded battery could allow these robots to operate independently in spaces inaccessible to larger devices. To achieve this, team employed a zinc-air battery, known for its high energy density and long lifespan, often used in hearing aids. The battery design includes a zinc electrode and a platinum electrode embedded in SU-8 polymer, commonly used in microelectronics. This setup enables the oxidation of zinc, generating a current.
In tests, the battery successfully powered a robotic actuator, a memristor for storing memories, and a clock circuit for timekeeping. It also ran sensors that detect environmental chemicals. Moving forward, the team aims to integrate the battery directly into robotic devices, envisioning applications such as drug-delivery robots that can navigate within the human body and then biodegrade after use. The researchers are also exploring ways to increase the battery’s voltage, which could unlock further applications. This tiny battery could become the foundation for a new era of autonomous, miniature robotics.
