Fabrication and characterization of magnetic porous microrobots

This study presents the design and fabrication of micro-scaled robots with a 3D, complex, porous structure produced by utilizing 3D laser lithography. The microrobots are coated with a 150 nm nickel surface for magnetic actuation in deionized water. When aligned in the vertical direction, the samples could be manipulated by applying an external magnetic field gradient in the horizontal direction. The average translational velocity of each microrobot can reach approximately 20 μm/s under a magnetic gradient of 1000 mT/m, which can be generated by a home-designed electromagnetic system with six individual orthogonal DT4E-core (a soft magnetic material) electromagnetic coils. Such magnetic driven micro-scaled robots can be used for target drug delivery or precise bio-particle transportation in in vivo environments such as blood, cerebrospinal fluid, and vitreous humor.