Fused deposition modeling (FDM) based 3D printing of microelectrodes and multi-electrode probes

Abstract

Electrode fabrication is one of the basic practices for electrochemists. Especially, microelectrodes are generally known as “hand-made” and their fabrication is often like an art. In this work, we report a new protocol for fabricating microelectrodes and multi-electrode probes based on recently matured 3D Fused Deposition Modeling (FDM) printing technique. The general concept is to print half of the insulating body in PETG, insert the (etched) metal or carbon wire(s) in the channel(s), and resume printing to complete the whole electrode. The printed electrodes are then sealed by heating and mechanically polished before use. The process requires only low-cost non-specialized facilities that can be easily equipped even in teaching laboratories. Single microelectrodes of Pt, C, Au, Ag, W and Cu with diameter below 5 µm are fabricated and examined by cyclic voltammetry and scanning electron microscopy. Furthermore, a multi-electrode probe consisting of W, Cu, Ag (oxidized to Ag/AgCl) and Pt is also printed and demonstrated for pH (potentiometric) and H2O2 (amperometric) sensing applications.