Issue 17, 2023

Fabrication of ITO microelectrodes and electrode arrays using a low-cost CO2 laser plotter


Good electronic (Rs = ∼5 Ω sq−1) and optical properties (transmittance: >83%) make indium tin oxide (ITO) an attractive electrode substrate. Despite the commercial availability of high-quality ITO and some low-cost methods for direct deposition being in use by now, the definition of patterns is still a concern. Putting their popularity and extensive use aside, the manufacturing of ITO electrodes so far lacks a rapid, highly reproducible, flexible, cost-effective, easy patterning process that could surpass difficult, time-consuming techniques such as lithography. Herein, we present a low-cost method based on CO2 laser irradiation for preparing ITO microelectrodes and electrode arrays. Electrodes of different sizes and shapes were examined to identify the performance of the proposed methods. Direct ablation of the ITO layer was optimized for rectangular electrodes of 25, 50, and 100 μm in width, while laser cutting of scotch tape stencils and subsequent wet etching were used to create circular electrodes with a diameter of 1.75 mm. A multielectrode array system consisting 8 of these circular electrodes was fabricated on a (25 × 25) mm2 plate, characterized electrochemically through cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM), and as an example application used for monitoring the anchoring behavior of HeLa and HepG2 cell cultures through cell-based electrochemical impedance spectroscopy. Together, the direct ablation method and preparation of laser cut stencils form a complete toolbox, which allows for low-cost and fast fabrication of ITO electrodes for a wide variety of applications. To demonstrate the general availability of the method, we have also prepared a batch of electrodes using a laser plotter in a local printing shop, achieving high intra-workshop reproducibility.

Graphical abstract: Fabrication of ITO microelectrodes and electrode arrays using a low-cost CO2 laser plotter

Supplementary files

Article information

Article type
29 Mar 2023
22 Jul 2023
First published
02 Aug 2023
This article is Open Access
Creative Commons BY license

Lab Chip, 2023,23, 3802-3810

Fabrication of ITO microelectrodes and electrode arrays using a low-cost CO2 laser plotter

K. Kappalakandy Valapil, M. S. Filipiak, W. Rekiel, E. Jarosińska, W. Nogala, M. Jönsson-Niedziółka and E. Witkowska Nery, Lab Chip, 2023, 23, 3802 DOI: 10.1039/D3LC00266G

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity