Meet the smallest ever remote-controlled walking robot. It was created by engineers at Northwestern University and resembles a tiny peekytoe crab. This crab is only half a millimeter wide and it can easily be perched on the side of a coin, but it can move and turn in every direction - bending, twisting, crawling, and even leaping. Let’s see what else it can do.
At this time, the study does not have a specific objective. It’s only experimental, but the results are already very promising and can be highly influential in many fields. The researchers propose several possible uses for their crab robot. These include repair or assembly of small structures or surgical assistance in minimally invasive procedures.
This is not the first time this team of engineers breaks records when it comes to robotics. They were also the first to create the smallest ever man-made flying structure. It was a winged microchip smaller than the head of the common ant. The main purpose of the structure is to monitor air pollution, airborne disease, and environmental contamination.
Seeing as they resemble crabs or tiny creatures, you might imagine that these robots can whizz by pretty fast, but so far, their speed is at an average of half a millimeter a second. While this may sound painfully slow, it is considered a more-than-average speed at such a small scale. You might even be shocked to discover that this robot does not use any electronic or hydraulic machinery to move. Instead, the very material from which it’s made, in combination with remote laser control, is what animates it.
The researchers used a shape-memory alloy material to build the robot. It transforms to its remembered shape when heated. When it is heated up, it contracts. When it cools down, it expands back to its original shape.
What heats the alloy is a laser beam. The direction of this beam determines the robot's direction of movement. John a. Rogers, Who lead the experimental work, explained that “because these structures are so tiny, the rate of cooling is very fast. In fact, reducing the sizes of these robots allows them to run faster.” As some wise man once said, everything is relative.
How does one come about manufacturing such little things? Well, the researchers at Northwestern will tell you it’s all child’s play. The manufacturing process is inspired by children’s pop-up books, a technique they introduced eight years ago.
First, they create the structures as flat, spread-out sheets. Then they lay these sheets onto a slightly stretched rubber layer. When this stretched rubber is relaxed, all parts are assembled, and the crabs pop into their final three-dimensional forms.
But why a crab of all things? The researchers once again show us their playful side, admitting that this was a creative whim: "With these assembly techniques and materials concepts, we can build walking robots of almost any size or 3D shape, but the students felt inspired and amused by the sideways crawling motions of tiny crabs."
They also created millimeter-sized robots that resemble inchworms, crickets, and beetles. I don’t know about you, but I wouldn’t mind letting this tiny crab join in as an assistant if I ever need surgery. And if you’re not convinced yet, try watching it in action: