Magmites are microrobotic agents developed at the Institute of Robotics and Intelligent Systems in 2006 by an interdisciplinary team of researchers (in alphabetical order: Dominic Frutiger, Bradley Kratochvil, and Karl Vollmers). The microrobots have dimensions of less than 300µm×300µm×70µm and are capable of moving forward, backward and turning in place, speeding up and slowing down, while reaching speeds in excess of 12.5 mm/s - 42 times the robot’s body length per second. The robots produce enough force to push 150µm×20µm gold disks and other objects. Sophisticated computer control allows for steering them through a maze in a fully automated fashion.
Colored scanning electron microscope micrograph
Colored scanning electron microscope micrograph (charging streaks visible)
Colored scanning electron microscope micrograph
In our work we have demonstrated how the robots can operate on a host of unstructured surfaces under both dry and wet conditions. Furthermore, various micro-objects ranging from beads to protein crystals have been successfully manipulated. To the same end, multi-agent studies have shown great promise to be used in cooperative tasks. Our robots exhibit an amazing degree of controllability, versatility, and performance. The robustness of our robots and systems leads to high experimental repeatability, which in turn enabled us to successfully compete in the RoboCup 2007 Nanogram Competition held in Atlanta, GA, USA.
Primary challenges in the building of untethered sub-millimeter sized robots include propulsion methods, power supply, and control. We present a novel type of microrobot termed Magmite that utilizes a new class of Wireless Resonant Magnetic Micro-actuator (WRMMa) that accomplishes all three tasks. The device harvests magnetic energy from the environment and effectively transforms it into impact-driven mechanical force while being fully controllable. It can be powered and controlled with oscillating fields in the kHz range and strengths as low as 2 mT, which is only roughly 50 times the average earth magnetic field.
While the goal of making microrobots play soccer remains a challenging problem for roboticists, the primary fields of application for this technology are to be found in life sciences and low-invasive medical treatment.
