%0 Journal Article
%T A Helical Microrobot with an Optimized Propeller-Shape for Propulsion in Viscoelastic Biological Media
%J Robotics | An Open Access Journal from MDPI
%D 2019
%R https://doi.org/10.3390/robotics8040087
%X One major challenge for microrobots is to penetrate and effectively move through viscoelastic biological tissues. Most existing microrobots can only propel in viscous liquids. Recent advances demonstrate that sub-micron robots can actively penetrate nanoporous biological tissue, such as the vitreous of the eye. However, it is still difficult to propel a micron-sized device through dense biological tissue. Here, we report that a special twisted helical shape together with a high aspect ratio in cross-section permit a microrobot with a diameter of hundreds-of-micrometers to move through mouse liver tissue. The helical microrobot is driven by a rotating magnetic field and localized by ultrasound imaging inside the tissue. The twisted ribbon is made of molybdenum and a sharp tip is chemically etched to generate a higher pressure at the edge of the propeller to break the biopolymeric network of the dense tissue. View Full-Tex
%U https://www.mdpi.com/2218-6581/8/4/87