3-dimensional electrode patterning within a microfluidic channel using metal ion implantation

TLDR

Electrical fields in microfluidic channels enable lab‑on‑a‑chip manipulation, but electrode patterning typically requires multi‑step optical lithography. We aim to use ion implantation to pattern 3‑D electrodes inside a PDMS microfluidic channel, offering advantages over planar designs. Electrodes are formed by 40° angled ion implantation through a metal shadow mask, enabling asymmetric particle alignment and dielectrophoretic focusing. Demonstrations with E.

Abstract

The application of electrical fields within a microfluidic channel enables many forms of manipulation necessary for lab-on-a-chip devices. Patterning electrodes inside the microfluidic channel generally requires multi-step optical lithography. Here, we utilize an ion-implantation process to pattern 3D 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. The advantages of three-dimensional structuring of electrodes within a fluidic channel over traditional planar electrode designs are discussed. Two possible applications are presented: asymmetric particles can be aligned in any of the three axial dimensions with electro-orientation; colloidal focusing and concentration within a fluidic channel can be achieved through dielectrophoresis. Demonstrations are shown with E. coli, a rod shaped bacteria, and indicate the potential that ion-implanted microfluidic channels have for manipulations in the context of lab-on-a-chip devices.