Humans may soon be able to interact with tiny robots small enough to fit in the bloodstream because of advancements in technology, according to ongoing research at Cornell.
Prof. Paul McEuen, physics, presented progress in creating cell-sized technology on Monday, examining the approaches underway at Cornell in making miniaturized machines powered by light.
The heading of his presentation stated that Moore’s Law — which says that the number of transistors in a microprocessor chip will increase by a factor of two about every two years, according to Nature — is “dead” and asks “now what?” This references the “crisis” of finding new ways to make computers more capable.
The shifted focus, McEuen explained, finds its source in physicist and former Cornell associate professor Richard Feynman explaining that humans should not only miniaturize information and computing, but also miniaturize machines on a tiny scale.
“I want to build things that I could inject into my bloodstream if I wanted to,” McEuen said, laughing. “I don’t know why I want to inject little things into my bloodstream but I do.”
Aiming for a size of 100 microns and the width of a human hair or smaller, this point of technological development has far-reaching implications for understanding the building blocks of life, one of McEuen’s interests.
His talk focused on the current efforts to build these cell-sized devices, including work on campus. Much of the development of this nanotechnology comes from already existing technology and an imitation of biological designs.
“There are two obvious places you can steal from,” he explained. “The first is biology of course, which has an absurd level of nanomachines at its disposal. The other is existing technology.”
There are five characteristics of cell-sized microbots, which must have 3D structure, actuation, sensing, communication and computation or memory, according to McEuen’s presentation. Additionally, the devices have two “camps,” including “smart panels” that “need to process information as the equivalent of a cell phone” and the “exoskeleton” that allows for movement.
To build the smart panels, groups at Cornell created Optical Wireless Integrated Circuits, or OWICs. Similar efforts from the University of Michigan and the University of California, Berkeley have been underway, according to the presentation, which compared the visible sizes of each on a penny. Cornell’s OWIC, at 100 microns, is barely a speck on the penny, hidden between the coin’s pillars of the Lincoln Memorial.
OWICs use light for power and communication, and McEuen described their progress on making these smart panels as the equivalent of a cell phone, in that they serve as “a generic platform, not a solution for a particular problem.”
“Once you develop this platform you can amp it up very easily,” he said. “We solved the communication problem, and then you can build whatever app on it or create your own circuit.”
To make the technology mobile, or build the exoskeleton, McEuen used paper origami as an analogy for the foldable cells focus of this technology.
The movement of the tiny devices then relies on a voltage-controlled bimorph, which means it has two layers combining thin graphene paper and a five nanometer thick platinum, making it the world’s thinnest electrically-actuated bimorph.
However, McEuen explained that improvements need to be made since “their force is relatively weak due their incredibly small size. They move well through water but struggle in gel.”
Future progress is focused on putting all the pieces together to create OptoBots — incredibly small machines powered by light. The size of these would be small enough for them to be picked up and transported by a pipette and made “using extraordinarily thin materials,” according to McEuen.
“We’re getting pretty excited,” McEuen said. “Depending on your way of looking at life you can say this looks really exciting, or this looks really scary.”
“We’ve come a far distance in the last couple of years,” he continued. “We’ve made smart panels that can do a lot of computation and communication, and we’ve gotten much better at building an exoskeleton.”
Though all of the devices McEuen presented were made at Cornell, he established that they are designed to “work together” in a “standard environment.”
“Once we get this right you can add more complexity at will, like a sensor that tells it to go left or right,” he said. “We’re all set to take it to the next level.”