A multiple microrobot system with thermally responsive microclampers

Various microrobots using an electromagnetic actuated (EMA) system have been studied in manipulating micro-objects and live cells with micro-size due to their free locomotion and precise controllability. In almost all researches, only single microrobot was controlled for microparticle manipulation. However, a single microrobot has a limitation on performing multiple roles. As a remedy of the limitation on a single microrobot, we propose a multiple electromagnetic actuated microrobot system for microparticle manipulation. First, for locomotion of the microrobots, the EMA system with 3 pairs of Helmholtz coils and 2 pairs of Maxwell coils is designed and fabricated. Second, the microrobots with different shapes are proposed for microparticle manipulation. In addition, for the selection of a specific microrobot among the multiple microrobot, microclamper using thermal responsive hydrogel (pNIPAm) and microheater for local heat transfer are used. As basic experiment, locomotion test of the single microrobot are executed. Finally, through the independent control of the multiple microrobots, we demonstrate manipulation of microparticles with different shapes (disk and cube). Consequently, we confirm that the multiple electromagnetic actuated microrobots can be used for microparticles manipulation and may be applied to cell manipulation and bioprinting.