August 2, 2022 – Imagine being wheeled into the operating room waiting for your surgical team – surgeons, anesthetistand… a little robot crab.
Scientists at Northwestern University have built an ultra-tiny robotic crab that could one day perform delicate surgical tasks — entering your body to sew up small, ruptured arteryclear blocked arteriesor track cancerous tumors.
The six-legged, half-millimeter-wide peeping crab, featured in a recent issue of scientific robot, is the world’s smallest remote-controlled walking robot. It can bend, twist, walk and jump, and operate using a remote-controlled laser.
It’s one of the latest advances in a decade of research aimed at building tiny machines that do practical work in hard-to-reach places. Thanks to advances in robotics and materials science, this synthetic crustacean and other “micro-robots” may help surgical teams sooner than you think. But what must happen before this future becomes a reality?
Making of Robot Crab
Bioelectronics engineer says making a flea-sized robotic crab ‘very easy’ John Rogers, Ph.D., who led the study. “It consists of three materials: polymer, shape memory alloy and glass.”
This polymer is a plastic-like material used in microelectronics. The second component, a shape-memory metal alloy, is combined with a polymer to form the joints and legs. The third component is a thin glass coating that coats the entire exterior of the robot’s body.
“The glass provides an exoskeleton. It provides rigidity to the robot as a whole,” Rogers said.
The robot operator points a laser at a specific location on the crab, triggering a thermal mechanism that makes the robot move.
“By shining it on certain limbs, we can create specific gaits,” Rogers explained, as the heat “unrolls” the crab. When the robot cools, it returns to its original shape. This folding and unfolding creates movement — the crab walks.
Rogers thinks his students chose the crab – they like the way it walks sideways – but says any creature could get smaller.
How will we use microrobots in medicine?
Although Rogers is reluctant to over-sell any specific medical use, surgical applications appear to hold the most promise for the technology. To use deep in the human body, Rogers said, “you probably need a swimmer — like a fish. There are other groups that study swimmers.”
Zhao LeiniPh.D., assistant professor of mechanical engineering at Stanford University, is such a scientist.in a newNature Communicationsarticle, She and her colleagues report on their “rotation-enabled wireless amphibious origami robot.” (Say it five times faster.)
The mini-robot – nearly the size of a fingertip – looks like a small cylinder and features an origami-inspired twist and bend pattern. It glides on viscous liquids and smooth surfaces and objects like human organs, rolling, flipping and spinning with the help of remote magnets. The folding and unfolding of the cylinder acts as a pumping mechanism for targeted delivery of liquid drugs.For example, it may bring drugs into the body to help stop internal bleedingZhao said.
“We are improving the system by further reducing its size for biomedical applications in narrower environments such as blood vessels,” she said.
In their paper, Zhao and her co-authors also show that tiny cameras and tiny tweezers can be put into millirobots for execution endoscopy and biopsy In theory, this could be less risky to patients than existing technologies.
But there was a lot of trial and error in the design phase of the robot, Zhao said.
“The trickiest part is optimizing swimming performance,” she said, because the density of the robot needs to be very close to the density of the liquid it “swims.”
Currently, Zhao’s amphibious robot is still in the experimental stage before animal testing. If it clears those hurdles, then it will be studied in human clinical trials.
That means it could be years before a swimming tank (or robotic crab) can help a heart surgery team or sew up an organ.
“This is early exploratory work,” Rogers said. “We’re trying to bring ideas into the wider community of researchers pursuing microrobotics that, in the hope that, over time, will eventually lead to actual clinical applications for surgery. Much of this is a starting point.”