Future applications of this technology include developing injectable robots for targeted drug delivery within the human body. The researchers aim to use biocompatible materials for these robots that would dissolve after completing their task.
Engineers and scientists at the Massachusetts Institute of Technology (MIT) have pioneered a new type of battery that could significantly advance the capabilities of cell-sized autonomous robots. The zinc-air batteries, measuring just 0.1 millimeters in length and 0.002 millimeters in thickness – thinner than a human hair – are designed to power miniature robots for a variety of applications, including drug delivery inside the human body and detecting leaks in gas pipelines.
The innovative batteries generate up to 1 volt of power by capturing oxygen from the air to oxidize zinc, producing a current sufficient to operate small circuits, sensors, or actuators. This breakthrough opens the door to deploying tiny robots that are not reliant on external power sources, thus enabling greater autonomy and functionality.
Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT and senior author of the study, stated, “We believe this development will be highly enabling for robotics. We’re integrating robotic functions directly into the battery and assembling these components into functional devices.”
The research, detailed in Science Robotics, was led by Ge Zhang PhD ’22 and Sungyun Yang, an MIT graduate student. Their work addresses a key challenge in micro-robotics: providing a reliable power source for devices that can sense and interact with their surroundings.
Traditionally, microscale robots have been powered by external sources like lasers, limiting their range and autonomy. In contrast, the zinc-air batteries developed at MIT allow these robots to operate independently, potentially reaching locations that were previously inaccessible.
Strano’s lab utilized zinc-air batteries, known for their high energy density and long lifespan, which are commonly used in hearing aids. The new design features a zinc electrode and a platinum electrode embedded in a polymer strip, SU-8, which is prevalent in microelectronics. The interaction between these electrodes and ambient oxygen generates a current capable of powering various components, including a robotic arm, memristors, and clock circuits. Additionally, the batteries can run sensors made from molybdenum disulfide and carbon nanotubes that detect chemical changes.
Looking ahead, the MIT team plans to integrate these batteries directly into robots, moving beyond the current use of external wiring. Strano envisions that these batteries will become a core element of future robotic designs, much like how electric cars are built around their batteries.
Future applications of this technology include developing injectable robots for targeted drug delivery within the human body. The researchers aim to use biocompatible materials for these robots that would dissolve after completing their task. They are also exploring ways to increase the battery’s voltage to further expand its potential uses.
Image: Courtesy MIT
