Automated open-loop control of directed self-assembly with multiple electrokinetic actuators in microfluidic devices

Directed self-assembly provides a novel processing route for the manufacture of structured materials. Future processes based on self-assembly will need to be equipped with suitable automated process controls for improving performance. Closed-loop control has been applied to directed self-assembly with one or two actuators when real-time and non-invasive observation is feasible. However, such observation may be challenging in practice. Furthermore, multiple actuators may have to be used for the self-assembly of complicated structures. In this work, an automated open-loop control method for directed self-assembly using multiple actuators is developed and tested experimentally. The method relies on a novel design of microelectrodes to assemble a specific number of particles in a desired area in a microfluidic device. An empirical model is developed to determine an optimal sequence of control actions. The experimental results show that the number of particles after the implementation of the open-loop control is close to the targeted number.