A new ultra-tiny robot invented by researchers at Georgia Tech is a mere two millimeters long and weighs just 5 milligrams. That’s an impressive feat and a new milestone for robotics.
These robots are able to be activated through vibration and can be printed via 3D printing and a technique called two-photon polymerization, which uses a photopolymerizable material that is able to become stiff if it is exposed to bright light. Some of this material is used in the 3D printing process, with a laser moving to perform the printing. Once the laser is done, the structure is washed off and then you’ll have the finished product. This is a reasonably fast process, but still perhaps not fast enough for the researchers if they want to create many thousands of these tiny robots.
It’s worth noting that the extremely small size of these robots (two millimeters long and with a weight of five milligrams) is not limited by the 3D printer, but by adhesion. The smaller you make the robot, the more it may adhere to the surface and be more difficult to remove.
No battery can be attached to these tiny robots. Therefore, they can only be powered (vibrated) by a piezoelectric actuator, allowing the robots to produce an electric current. The robots can resonate at a vibration frequency of approximately 6.3 kHz, though it is possible to change around the frequency and amplitude of the vibrations for different robots.