One day microscopic robots could be crawling through your body, clearing out disease or delivering drugs. And now we’re one step closer to that future, as scientists from Cornell University have created tiny robots powered by pulses of laser light.
First presented at a conference last year, the micro-robots look fairly simple in their design. They’re about five microns thick, 40 microns wide and between 40 and 70 microns long, roughly the size of a single-celled organism like a paramecium. Their bodies contain a simple silicon photovoltaic circuit that powers their legs, which are made of electrochemical actuators.
The legs are made of strips of platinum just a few dozen atoms thick, with a layer of inert titanium on one side and polymer panels along the top. To make the bots walk, lasers are flashed onto the photovoltaics on the body, which send a positive electric charge streaming into the platinum. That causes negative ions from the surrounding solution to cling to the exposed platinum between the polymer panels and make it bend like a knee. By alternating the lasers between the front and back legs, the robots can crawl.
The team says that the micro-robots are strong and robust for their size, and operate on a voltage of just 200 millivolts and power of 10 nanowatts. But perhaps the most important thing about them is they’re relatively easy to make using standard microchip manufacturing procedures, such as lithography and atomic layer deposition. As many as a million of the bots can fit onto one 4-in (100-mm) silicon wafer.
“While these robots are primitive in their function – they’re not very fast, they don’t have a lot of computational capability – the innovations that we made to make them compatible with standard microchip fabrication open the door to making these microscopic robots smart, fast and mass producible,” says Itai Cohen, lead researcher on the study. “This is really just the first shot across the bow that, hey, we can do electronic integration on a tiny robot.”
The researchers say they’re currently investigating how to add more sophisticated electronics and capabilities onto these micro-robots, with the long-term goal of using similar ones in the human body. Once there, they could perform a variety of helpful tasks like delivering drugs to specific tissues, clearing cholesterol out of arteries, or patching up injuries. They may be joined by a whole army of other designs that swim, crawl, flip-flop, squeeze or roll through the body.
The study was published in the journal Nature. The team describes the work in the video below.
Source: Cornell University
