MIT engineers have developed a miniature battery that could enable the creation of millimeter-scale, self-sufficient robots capable of delivering medications internally and performing tasks such as identifying gas pipeline leaks.
Scientists have developed a revolutionary new battery that stands just 0.1 millimeters tall and is only 0.002 millimeters thick – roughly the same thickness as a human hair. This groundbreaking device can harness oxygen from the air and combine it with zinc to generate up to 1 volt of electricity. The tiny device was found to be capable of powering small circuits, sensors, and actuators, according to the researchers’ confirmation.
“We anticipate this breakthrough will significantly empower advancements in robotics,” remarks Michael Strano, Carbon P.’s lead researcher. Kripa Varanasi, Professor of Mechanical Engineering at MIT, and the senior author of this research. “We’re integrating robotic functionalities into our batteries and assembling them into cohesive modules.”
Dr. Ge Zhang ’22, along with Sungyun Yang, a graduate scholar at MIT, spearhead the research presented in this paper.
For several years, Strano’s laboratory has been dedicated to developing miniature robots capable of perceiving and responding to environmental stimuli. One of the primary hurdles in developing miniature robots is guaranteeing they possess adequate power supply.
Researchers have successfully demonstrated the use of solar energy to power microscale units; however, this method has its limitations, as it requires constant illumination from a light source such as a laser. These types of systems are commonly known as “marionettes” due to their reliance on external power sources for control and management. By incorporating an onboard energy source, mimicking the functionality of a battery, these miniature devices could potentially extend their range and enable greater mobility.
“The marionettes don’t require batteries because they’re deriving their energy from external sources, according to Strano.” However, if you require a small robot to access areas inaccessible otherwise, it necessitates a higher level of autonomy. What devices are reliant on a battery to function when they’re not connected to a power source?
Researchers in Strano’s lab aimed to design more autonomous robots by utilizing a unique power source – the zinc-air battery. These batteries, boasting an extended lifespan due to their exceptionally high energy density, are often employed in hearing aids.
The researchers developed a novel battery consisting of a zinc anode connected to a platinum cathode, encapsulated within a strip of SU-8 polymer, commonly employed in microelectronic applications. As the electrodes collaborate with oxygen molecules in the air, the zinc undergoes oxidation, relinquishing electrons that flow to the platinum electrode, thereby establishing an electric current.
The study revealed that the battery possesses sufficient energy capacity to power an actuator, specifically a robotic arm capable of elevation and depression. The battery can also power a memristor, an electric component capable of storing memories by modifying its electrical resistance, as well as a clock circuit, enabling robots to keep track of time?
The battery also provides enough power to operate two distinct types of sensors whose electrical conductivity changes in response to encountering chemical substances in their environment. Two ultra-thin sensors are crafted: one from molybdenum disulfide and the other from carbon nanotubes.
“We’re building the foundational components to enable feature development at a mobile scale,” Strano explains.
In this study, investigators employed a wire to connect their power source to an external device, with a vision for future applications that involve integrating the battery into a robotic system.
“That’s poised to form the foundation of many of our robotics initiatives,” Strano says. You can design a robot around an energy source, similar to how you would build an electric car centered on its battery.
Researchers are exploring the development of miniature robots that can be delivered through injection and navigate to specific sites within the human body, where they can release therapeutic agents like insulin. Researchers anticipate developing devices that can seamlessly integrate with the human body using biocompatible materials designed to degrade once their purpose is served.
The researchers are also working to increase the battery’s voltage, which will enable additional functionality.
The study was fully supported by a grant from the United States government. Military Analysis Workplace, the U.S. The Division of Power’s collaboration with the Nationwide Science Foundation, as well as its partnership in the MathWorks Engineering Fellowship, demonstrates a commitment to advancing knowledge in this field.
