title: Automated Assembly of Vascular-Like Microtube With Repetitive Single-Step Contact Manipulation.
abstract: Fabricated vessel-mimetic microtubes are essential for delivering sufficient nutrient to engineered composite tissues. In this paper, vascular-like microtubes are engineered by automated assembly of donut-shaped micromodules that embed fibroblast cells. A microrobotic system is set up with dual manipulators of 30-nm positioning resolution under an optical microscope. The system assembles the micromodules by repeated single-step pick-up motions. This process is specifically designed to avoid human interference and ensure high reproducibility for automation. We optimized the single-step motion by calibrating the key parameters (the micromodule dimensions) in a force analysis. The optimal motion achieved a 98% pick-up success rate. The automated repetitive single-step assembly is achieved by an algorithm that acquires the 3-D location and tracks the micromanipulator without being affected by low contrast. The accuracy of the acquired 3-D location was experimentally determined as approximately 1 pixel (2 μm under 4× magnification), and the tracking under different observation conditions is proved effective. Finally, we automatically assembled microtubes at 6 micromodules/min, sufficiently fast for fabricating macroscopic vessel-mimetic substitutes in biological applications.
authors.forename: Huaping
authors.initials: H
authors.lastname: Wang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Huang
authors.forename: Qing
authors.initials: Q
authors.lastname: Shi
authors.forename: Tao
authors.initials: T
authors.lastname: Yue
authors.forename: Shaoqi
authors.initials: S
authors.lastname: Chen
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nakajima
authors.forename: Masaru
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Toshio
authors.initials: T
authors.lastname: Fukuda
mesh_terms: D000465:Algorithms; D000818:Animals; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D051379:Mice; D008846:Micromanipulation / Q000295:instrumentation* / Q000379:methods*; D055806:Microvessels / Q000502:physiology*; D008955:Models, Cardiovascular; D041681:NIH 3T3 Cells; D015203:Reproducibility of Results; D012371:Robotics / Q000295:instrumentation; D023822:Tissue Engineering / Q000379:methods*