By Tom Jowitt
Researchers have developed a tiny robot that could, in theory, swim through the bloodstream of a human being in order to deliver medicine to the problem area.
The development was made by a team of researchers led by Prof. Peer Fischer at the Max Planck Institute for Intelligent Systems in Stuttgart.
The problem for researchers is that swimming or locomotion through water is not actually possible for tiny machines, because the viscosity is not right. However, in biological fluids such as blood, or the fluid found in an eye, movement does become possible, if driven by magnetic fields, as that fluid is a non-Newtonian fluid (i.e., the viscosity changes in response to pressure).
Nature Communications revealed that the researchers have now developed a robotic micro-scallop capable of swimming through this non-Newtonian fluid. Essentially, the robot moves like a scallop, opening and closing a pair of shells connected by a tiny hinge, to propel itself to the problem location within the human body.
The micro-scallop robot was made by a 3D printer, and each shell measures 300 microns thick and 800 micros wide. A human hair, in comparison, is 100 microns in diameter, so we are talking pretty small here. With something this tiny, it is not possible for it to carry all the motors, controllers, and indeed fuel/energy to power it. Instead, the micro-scallop has "rare-earth micro magnets" on each shell, so locomotion relies on exposure to an external magnetic field, which will cause the shells to open and close at different rates, and thus move.
A video of the development can be found here.
"This is great news because we can now use really simply actuation schemes ... to build swimming micro robots that can move through tissue and biomedical relevant fluids," said Prof. Peer Fischer.
Developments like these may sound like something from a science fiction movie, but in reality technology advances are helping scientists explore new avenues in fields like medicine.
Last month, for example, Google revealed that it is developing a "nanoparticle" pill, which once swallowed, will enter the bloodstream and "sniff out" the dangerous chemical signals given off by cells as they become diseased.
And in January of this year Google revealed it had developed special contact lenses equipped with miniaturized sensors to analyze the tears in the eyes of diabetes patients, in order to determine when their blood sugar levels need to be adjusted.
Then in July it announced that it had teamed up with Swiss pharmaceutical giant Novartis to develop these 'smart' contact lenses to help people with diabetes track their blood glucose levels.