Massachusetts Institute of Technology (MIT) researchers have designed a zinc-air microbattery smaller than a grain of sand, potentially transforming the field of microscale robotics for applications ranging from targeted drug delivery to gas pipeline leak detection.
In a groundbreaking study published in Science Robotics on August 16, MIT engineers have unveiled a tiny battery that could power autonomous, cell-sized robots. This development marks a significant step towards creating miniature devices capable of operating independently within the human body and in other challenging environments.
Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT and senior author of the study, emphasised the potential impact of this innovation: "We think this is going to be very enabling for robotics. We're building robotic functions onto the battery and starting to put these components together into devices."
The microbattery, measuring just 0.1 millimeters in length and 0.002 millimeters in thickness (roughly the width of a human hair), utilises a zinc-air design. It captures oxygen from the air to oxidize zinc, generating a current with a potential of up to 1 volt - sufficient to power small circuits, sensors, or actuators.
Lead authors Ge Zhang and Sungyun Yang demonstrated the battery's capabilities by using it to power various components, including:
1. A robotic arm that can be raised and lowered
2. A memristor for storing memories of events
3. A clock circuit for time-tracking
4. Two types of chemical sensors with variable electrical resistance
This advancement addresses a crucial challenge in microscale robotics: providing autonomous power. Previous attempts relied on external power sources, limiting the robots' range and functionality. Strano explained, "If you want a small robot to be able to get into spaces that you couldn't access otherwise, it needs to have a greater level of autonomy. A battery is essential for something that's not going to be tethered to the outside world."
The research team envisions numerous applications for this technology. One promising area is targeted drug delivery within the body. Think the Dennis Quaid 'classic', Inner Space. They are working on designing tiny robots that could be injected into patients, navigate to specific sites, and release medications like insulin. For such applications, the devices would be constructed from biocompatible materials designed to break down safely after use.
Future research will focus on incorporating the battery directly into robotic devices and increasing its voltage to enable additional applications. Strano likened this approach to building an electric car around its battery, stating, "This is going to form the core of a lot of our robotic efforts. You can build a robot around an energy source."
The study was supported by funding from the U.S. Army Research Office, the U.S. Department of Energy, the National Science Foundation, and a MathWorks Engineering Fellowship, underscoring the wide-ranging interest in this innovative technology.
The development of this microscopic zinc-air battery represents a significant leap forward in the field of miniature robotics. As research continues, these tiny power sources could unlock new possibilities in medicine, environmental monitoring, and beyond, changing how we approach challenges at the microscopic scale.