'Smaller than a grain of salt': Researcher develop world's smallest programmable, autonomous robots

Researchers at the University of Pennsylvania, in collaboration with the University of Michigan have created, what are believed to be the world’s smallest fully programmable, autonomous robots, measuring roughly about 200 by 300 by 50 micrometers, smaller than a grain of salt and costing about one penny each to produce. These devices represent a pivot in robotics, operating at the scale of many microorganisms yet equipped with the computing power, sensors and propulsion systems needed to sense, decide and act without external control.

According to media reports these microscopic swimming machines that can independently sense and respond to their surroundings, operate for months. "We've made autonomous robots 10,000 times smaller," said Marc Miskin, assistant professor in electrical and systems engineering at Penn and senior author of a pair of studies published in Science Robotics and the Proceedings of the National Academy of Sciences. "That opens up an entirely new scale for programmable robots."

How tiny robots move, sense and think

Unlike traditional robots with joints or moving parts, the new micro-robots generate an electrical field that nudges ions in the surrounding solution. This electrokinetic propulsion allows them to 'swim' through liquids and even coordinate group motion, similar to a school of fish. Powered by light captured by microscopic solar panels, each robot also carries a tiny onboard computer and sensors that enable it to respond to its environment, all fit on a chip that is a fraction of a millimeter in size.

Programming at the microscale

Programming these minuscule machines posed a significant challenge. The computer chips operate on extremely low power, it produces only around 75 nanowatts of power, which is over 1,00,000 times less power than what gadgets like smartwatches require. To run the robot's computer on such little power, the Michigan team developed special circuits that operate at extremely low voltages and bring down the computer's power consumption by more than 1000 times.

The robots also have unique identifiers so that each can be individually programmed. Instructions are loaded via light pulses, and complex actions can be encoded efficiently into the limited memory. The unique design means that the robots can be instructed to perform different roles in a larger task, opening up possibilities for coordinated microscale work.

Potential applications in medicine and manufacturing

Because of their size and autonomy, these micro-robots could transform several fields. In medicine, they may be helpful in monitoring the health of individual cells, also in tracking temperature variations associated with disease processes along with other benefits. In manufacturing, they could help construct microscale devices that are too small for conventional tools to build.

According toTechxplore.com via Phys.org, the researchers behind the project describe this achievement as the first chapter in a broader future for microscopic robotics. By demonstrating that a brain, propulsion system and sensors can all fit into something barely visible without magnification, they have opened the door to more sophisticated micro-machines.