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World’s First Ciliary Stroke Motion Microrobots

  • 조회. 1847
  • 등록일. 2016.08.31
  • 작성자. Administrator

World’s First Ciliary Stroke Motion Microrobots






A research team led by Professor

Hongsoo Choi developed microrobots with high propulsion efficiency in highly-viscous

fluid environments, applying propulsion techniques that mimic the ciliary stroke

motion of paramecia.



 



The research team at DGIST developed ciliary

microrobots with high propulsion efficiency in highly-viscous fluid

environments in the human body such as blood by mimicking the movement of

paramecia’s cilia. The ciliary microrobots are for chemical and cell delivery that

can be precisely controlled and that move via paramecium-like ciliary motion.



 



Professor

Choi’s research team
 succeeded in fabricating the

world’s first ciliary microrobots utilizing ultra-fine three-dimensional

processing technology and asymmetric magnetic drive technology by applying

microorganism’s ciliary movement, which thus far had only been theorized but

never put into practice. 






 









a) SEM

image of microorganism, Paramecium, using ciliary stroke motion.



b) Design

layouts for artificial ciliary microrobots.



c) Overall

fabrication process for the ciliary microrobot using 3D laser lithography and

metal sputtering.  



d) SEM

image of ciliary stroke motion microrobots developed by Prof. Choi’s research

team (3D view, scale bar = 100
μm)



e) SEM image of ciliary stroke motion microrobots

developed by Prof. Choi’s research team (top view, scale bar = 100
μm)



 



Microfluidic

environments in which microorganisms move include highly viscous environments like

the human body’s internal fluids; thus, in a macro environment, it is difficult

to create propulsion with swimming-based mechanisms such as inertia-based

symmetrical rowing like that used by large animals such as humans. As such,

microorganisms moving in highly-viscous environments utilize various other

propulsion techniques such as spiral drive motion, progressive wave motion,

ciliary asymmetric reciprocating motion, and the like.



 



Microrobots

that use propulsion mechanisms such as spiral drive motion and progressive wave

motion were first realized and implemented at the Zurich Federal Institute of Technology,

Switzerland; University of Twente, Netherlands; and Harvard University, USA. However,

the development of microrobots that move utilizing ciliary motion has thus far

been absent due to the difficulty of producing a microstructure with a large

number of cilia as well as with asymmetrical drive.   



 



Professor

Choi’s research team has produced a ciliary microrobot with nickel and titanium

coating on top of photo-curable polymer material, using three-dimensional laser

process technology and precise metal coating techniques.



 



In

addition, the team verified that the speed and propulsion efficiency of their newly-developed

microrobots were much higher than those of existing conventional microrobots moving

under magnetic attraction drive after measuring the ciliary microrobots’

movement utilizing asymmetrical magnetic actuation technology.











a) Screen

capture of linear motion of ciliary microrobots according to reciprocating

magnetic drive under magnetic field control



b) Screen

capture of rotary motion of ciliary microrobots according to reciprocating

magnetic axis rotation under magnetic field control



c) The

movement of ciliary microrobots tracing the letters D. G. I. S. T.



  



The

maximum speed of ciliary microrobots with a length of 220 micrometers and a

height of 60 micrometers is 340 micrometers per second, thus they can move at least

8.6 times faster and as much as 25.8 times faster than conventional microrobots

moving under magnetic attraction drive.



 



In

comparison to previously developed microrobots, Professor Choi’s ciliary

microrobots are expected to deliver higher amounts of chemicals and cells to

target areas in the highly viscous body environment thanks to their ability to

freely change direction and to move in an 80 micrometer-diameter sphere to the

target point shown in the experiment using the magnetic field.



 



Professor

Choi from DGIST’s Department of Robotics Engineering said, “With precise three-dimensional

fabrication techniques and magnetic control technology, my team has developed

microrobots mimicking cilia’s asymmetric reciprocation movement, which has been

never realized so far. We’ll continually strive to study and experiment on

microrobots that can efficiently move and operate in the human body, so that

they can be utilized in chemical and cell delivery as well as in non-invasive

surgery.”



 



This

research outcome was published in the online edition of
Scientific Reports, a sister publication of Nature, on July 29, 2016. Professor Choi Hong-soo from DGIST’s Department of Robotics Engineering

was a corresponding author and PhD student Kim Sang-won from DGIST’s Department of Robotics Engineering participated

as the first author.



 



 



Journal Reference



Sangwon Kim, Hongsoo Choi, et. al., “Fabrication and

Manipulation of Ciliary Microrobots with Non-reciprocal Magnetic Actuation”,

Scientific Reports 2016.



http://www.nature.com/articles/srep30713



 



Related video clips :



http://www.arirang.com/News/News_View.asp?nSeq=194203






https://www.youtube.com/watch?v=5utpPHpuJdA