A team of researchers from ETH Zurich in Switzerland has taken inspiration from starfish larva in creating their microrobots. The robot propels itself using tiny hairs to move through the stomach and accurately deliver medicine to diseased cells.
CNet reported, their unnamed robot only measures about a quarter of a millimeter and can swim through surfaces by moving its tiny hairs called cilia, found in all organisms, like a starfish larva.
Using Ultrasound Waves to Move Synthetic Cilia of Robots
Microrobots are typically designed based on natural microorganisms, like bacteria or algae. But for the first time, researchers from ETH Zurich have developed a microscopic robot inspired by starfish larva. They used ultrasound waves to move the robot's synthetic cilia and propel it through the stomach.
As CNet reported, the ultrasound-activated synthetic system mimics how the ciliary bands of starfish larva move and replicate larva's motion and manipulation techniques. The ultrasound waves make the synthetic cilia oscillate 10,000 times per second, equivalent to 1,000 times faster than the natural cilia found in baby starfish.
In the video shared by researchers, it can be seen that a minuscule vortex is created in the front and behind the robot due to its rapid beating. The robot moves forward using a suction effect created by the vortex and a thrust by its rear side, allowing it to drive straight.
The microbeads in the video surrounding the robot are added to the water to demonstrate how it moves in a circular pattern as the microscopic robot propels itself forward.
Lead researcher Daniel Ahmed, a Professor of Acoustic Robotics for life sciences and healthcare, said in the university's press release that their team initially just wanted to test whether they could create vortices similar to a starfish larva with rows of cilia attached to it. They used photolithography to construct the microrobot with synthetic cilia and applied ultrasound waves from an external source to make it oscillate.
They described their microrobots in full in their study, titled "Ultrasound-Activated Ciliary Bands for Microrobotic Systems Inspired by Starfish" published in the journal Nature Communications.
Application of Microrobots
Science Times previously reported that scientists from Cornell University are also developing microswimmers inspired by bacteria and sperm cells. Their application is focused on targeted-drug delivery on body parts that currently can not be accessed due to some limitations.
According to New Primer, targeted-drug delivery is also a widely discussed application for these microrobots inspired by starfish larva to deliver medicines directly to the site, like a stomach tumor. Scientists said that this method could ensure that the drug is used more efficiently and reduce the potential side effects of the drug.
However, they also acknowledged some limitations in steering the robot inside the human body, as it would require sharp imaging in real-time to help doctors know the location of the microscopic robot. The team also plans to incorporate contrast agents used in medical ultrasound imaging to make microswimmers more visible.
Ahmed said that they are looking into other robot applications outside medicine, like moving around tiny amounts of liquid for further research and possible applications in the industrial setting.
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