The zinc-air microbattery. [Image courtesy of MIT/the researchers]
MIT engineers say they developed tiny batteries that could enable the deployment of cell-sized autonomous robots for drug delivery in the human body.
The battery measures 0.1. mm long and 0.002 mm thick, coming at roughly the thickness of a human hair. It can capture oxygen from air and use it to oxidize zinc. According to an article on the MIT website published on Aug. 15, the battery creates a current with a potential of up to one volt, potentially powering a small circuit, sensor or actuator.
Ge Zhang and Sungyun Yang, an MIT graduate student, served as the lead authors of the research, which appears in Science Robotics.
The researchers say that to create robots that could become more autonomous, they used a zinc-air battery that has a longer lifespan than other types. Such batteries have a high energy density and are used in devices like hearing aids.
In their study, they showed that the battery could provide enough energy to power an actuator. In this case, it was a robotic arm that can be raised and lowered. It could also power a memristor or run two different types of sensors that change electrical resistance when they encounter chemicals in the environment. One sensor is made from atomically thin molybdenum disulfide and the other from carbon nanotubes.
They used a wire to connect the battery to an external device but plan to build robots that incorporate the battery within a device.
The researchers say they designed tiny robots that could be injected into the human body, seek out a target site and then release a drug, such as insulin. For use in the human body, the researchers say the devices would be made of biocompatible materials that would break apart once no longer needed.