title: Motion Control of Urea-Powered Biocompatible Hollow Microcapsules.
abstract: The quest for biocompatible microswimmers powered by compatible fuel and with full motion control over their self-propulsion is a long-standing challenge in the field of active matter and microrobotics. Here, we present an active hybrid microcapsule motor based on Janus hollow mesoporous silica microparticles powered by the biocatalytic decomposition of urea at physiological concentrations. The directional self-propelled motion lasts longer than 10 min with an average velocity of up to 5 body lengths per second. Additionally, we control the velocity of the micromotor by chemically inhibiting and reactivating the enzymatic activity of urease. The incorporation of magnetic material within the Janus structure provides remote magnetic control on the movement direction. Furthermore, the mesoporous/hollow structure can load both small molecules and larger particles up to hundreds of nanometers, making the hybrid micromotor an active and controllable drug delivery microsystem.
authors: Max Planck Institute for Intelligent Systems Institution , Heisenbergstraße 3, 70569 Stuttgart, Germany.
authors: Xing
authors: X
authors: Ma
authors: Max Planck Institute for Intelligent Systems Institution , Heisenbergstraße 3, 70569 Stuttgart, Germany.
authors: Xu
authors: X
authors: Wang
authors: Stuttgart Center for Electron Microscopy, Max Planck Institute for Solid State Research , Heisenbergstraße 1, 70569 Stuttgart, Germany.
authors: Kersten
authors: K
authors: Hahn
authors: Max Planck Institute for Intelligent Systems Institution , Heisenbergstraße 3, 70569 Stuttgart, Germany.|Institució Catalana de Recerca i Estudis Avancats (ICREA) , Pg. Lluís Companys 23, 08010 Barcelona, Spain.|Institut de Bioenginyeria de Catalunya (IBEC) , Baldiri i Reixac 10-12, 08028 Barcelona, Spain.
authors: Samuel
authors: S
authors: Sánchez
keywords: hybrid micromotor; mesoporous silica; micromotors; motion control; self-propulsion