Biocompatible , accurate , and fully autonomous : a sperm - driven micro - bio - robot Islam

We study the magnetic-based motion control of a sperm-flagella driven Micro-Bio-Robot (MBR), and demonstrate precise point-to-point closed-loop motion control under the influence of the controlled magnetic field lines. This MBR consists of a bovine spermatozoon that is captured inside Ti/Fe nanomembranes. The nanomembranes are rolled-up into a 50 μm long microtube with a Islam S. M. Khalil and Veronika Magdanz equally contributed towards the preparation of this work. Electronic supplementary material The online version of this article (doi: 10.1007/s12213-014-0077-9) contains supplementary material, which is available to authorized users. I. S. M. Khalil ( ) German University in Cairo, New Cairo City 13411, Egypt e-mail: [email protected] V. Magdanz · O. G. Schmidt Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany V. Magdanz e-mail: [email protected] O. G. Schmidt Material Systems for Nanoelectronics, University of Technology Chemnitz, Chemnitz, Germany e-mail: [email protected] S. Sanchez Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, 70569 Stuttgart, Germany e-mail: [email protected] S. Misra MIRA–Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede 7500AE, Netherlands e-mail: [email protected] diameter of 5-8 μm. Our MBR is self-propelled by the sperm cell and guided using the magnetic torque exerted on the magnetic dipole of its rolled-up microtube. The selfpropulsion force provided by the sperm cell allows the MBR to move at an average velocity of 25±10 μm/s towards a reference position, whereas the magnetic dipole moment and the controlled weak magnetic fields (approximately 1.39 mT) allow for the localization of the MBR within the vicinity of reference positions with an average region-ofconvergence of 90±40μm. In addition, we experimentally demonstrate the guided motion of the MBR towards a magnetic microparticle with applications towards targeted drug delivery and microactuation.