Designing Microdevices Operated through Self-Organizations of Microtubules and Kinesin Motors

Abstract

Fish melanocytes change their colors through aggregation and dispersion of melanophores. The aggregation and dispersion of melanophores make the appearances of fish melanocytes bright and dark, respectively. The movements of malanophores are driven by biological molecular motors, motor proteins. Inspired by this mechanism, we have envisioned an optical microdevice powered by motor proteins. That is, in arrays of microscale chambers, melanophore-imitated particles, whose surfaces are covered with kinesin motors, are aggregated and dispersed through formations and disassemblies of microtubule asters, respectively. In order to realize such optical device, exploring possible designs of the device is required to test the feasibility of the device. However, laborious experimental procedures hamper such explorations. An alternative way of the exploring would be use of computer simulations. Previously, we have shown the power of computer simulations in designing Lab-on-a-Chip devices powered by motor proteins. Here, we performed systematic explorations of designs of the envisioned device. To this end, we modeled a microtubule as the Kramers chain of a linear polymer, and performed Brownian dynamics simulations. The simulations showed aster formations of microtubules in chambers of various shapes, such as thin triangle, square and hexagonal prisms. We will discuss effects on the aster formations of the size of microscopic chambers, microtubule properties, and motor protein properties. Through the computer simulation, we will show design guidelines for the optical device.