Microrobots designed using biomimicry principles are being developed to perform non-invasive surgical procedures in the human body. Ha and Goo of Konkuk University in South Korea (reference 1) and Zhang, Peyer, Kratochvil and Nelson of the Institute of Robotics and Intelligent Systems at the Swiss Federal Institute of Technology (2) have built and tested swimming microrobots with a flagella propulsion system derived from bacteria such as E. coli. This can enable a microrobot to travel independently within the human body, using channels such as the cardiovascular system and urogenital system, to the operation site. The Multiscale Biomimetics Systems Laboratory at Seoul University is developing surgical microrobots for tasks such as clearing chronic obstructions in coronary arteries - Chronic Total Occlusions - (3) that are problematic using existing surgical techniques (4). Edd et al. of the Department of Mechanical Engineering, University of California Berkeley, have proposed that such swimming surgical microrobots can be used for destroying kidney stones (5).1=Ha N. S. and Goo N. S. (2010) Propulsion Modelling and Analysis of a Biomimetic Swimmer, Journal of Bionic Engineering, 7:259-2662=http://www.iris.ethz.ch/msrl/research/micro/helical_swimmers3=http://mbsl.snu.ac.kr/wiki/doku.php id=research:research#biomimetic_microrobots_for_cardiovascular_diseases_and_colon_endoscope4=Aziz S. and Ramsdale D. R. (2005) 'Chronic total occlusions - a stiff challenge requiring a major breakthrough: is there light at the end of the tunnel?' Heart, 91:42-485=Edd J, et al (2003) 'Biomimetic propulsion for a swimming surgical micro-robot' IEEE/RSJ International Conference on Intelligent Robots and Systems, Proceedings volume 3:2583-2588
Escherichia coli (E. coli) bacteria propel themselves by the helical movement of whip-like protuberances called flagella. The source of the rotary motion is a motor at the base of the flagella, powered by the movement of hydrogen ions across the cell membrane. Helical flagella motion is extremely effective at moving the bacteria through liquid media, providing speeds of up to 60 cell lengths/second. The bacteria's motor is comparable in structure and function to an electric motor. As mentioned above, researchers have been inspired by nature to build swimming microrobots that replicate the motion of bacteria such as E. coli. Work like this provides a precedent for the construction of machines that function at a microscopic scale, as bacteria do.
Firstly, surgery is an invasive procedure that requires incisions to be made through tissue, such as skin and muscle, between the surgeon and the location in the body to be operated on. This causes "collateral damage" to the body and consequential physiological stress. In recent years keyhole surgery, aka minimally invasive surgery, made practical by advances in digital technology, has mitigated this collateral damage. Surgical microrobots are a further step, enabling surgical procedures to be undertaken with no collateral damage.Secondly, precision in traditional surgery is delimited by the manual dexterity of the surgeon. Surgical microrobots, being very small entities, would be able to offer a much higher level of precision - microscopic sensing and action.Edit Summary