Transparent Metal Mesh Electrodes Microfabricated by Structuring Water-Soluble Polymer Resist via Laser Ablation

We present a method of manufacturing semitransparent mesh-shaped electrodes using laser structuring of a polymer followed by resistive thermal evaporation of a metallic layer. Toluene, used for preparing a polymer solution and its layer deposition, has been replaced with ethanol, thus eliminating a hazardous solvent from the process. The influence of adding photosensitizers to the polymer base on the structuring laser ablation threshold has been investigated, with most prominent reduction from 1.3 to ∼0.3 W for a UV laser line irradiation. Finally, and most importantly, the key step of this method, the development step that includes the removal of a resist, was carried out in water, thus ruling out completely other environmentally hazardous solvents from the process. Additionally, it does not require cleanroom conditions. The final electrode prototype was tested in electro- and thermomodulation measurements, proving its usefulness in spatial control of electric field and heat generation. Consequently, our work paves the way for other applications requiring patterned semitransparent electrodes made in a sustainable process.