Programmable patterning of polymeric microparticles by floating electrodes-assisted electrospray

We introduce a new method for patterning one or multiple types of polymeric microparticles by electrospraying them toward a collecting surface patterned with an array of microelectrodes. By independently programming the electric state of each microelectrode, microparticles can be confined within desired regions with a high patterning contrast. The patterning principle and the role of the floating electrodes are discussed. Copatterning of multiple types of particles on a planar surface and along the vertical direction is demonstrated. With the superior copatterning capacity and the simple configuration, this work is expected to facilitate the development of biosensing, microscale tissue engineering and other microparticle-based total analysis. (technical note)