Tuning parameters of metal ion implantation within a microfluidic channel

Abstract

Applying electrical fields is a simple and versatile method to manipulate and reconfigure optofluidic devices. Several methods to apply electric fields using electrodes on polymers or in the context of lab-on-a-chip devices exist. In this paper, we utilize an ion-implanted process to pattern electrodes within a fluidic channel made of polydimethylsiloxane (PDMS). Electrode structuring within the channel is achieved by ion implantation at a 40° angle with a metal shadow mask. In previous work using the ion-implantation process, we demonstrated two possible applications in the context of lab-on-a-chip applications. Asymmetric particles were aligned through electro-orientation. Colloidal focusing and concentration was possible with negative dielectrophoresis. In this paper, we discuss the different electrode structures that are possible by changing the channel dimensions. A second parameter of ion implantation dosage prevents the shorting of electrodes on the side wall or top wall of the fluidic channel to the bottom. This allows for floating electrodes on the side wall or top wall. These type of electrodes help prevent electrolysis as the liquid is not in direct contact with the voltage source. Possible applications of the different electrode structures that are possible are discussed.