Three-dimensional microstructures fabricated by multi-step electrochemical etching of aluminum sheet

We present a fabrication process for three-dimensional (3D) microstructures using multi-step electrochemical etching of metal foils. The present process offers advantages of simple, cost-effective, and fast process with uniform and well-controlled material property. In the experimental study, we performed single-step electrochemical etching of 2D cantilever array and multi-step electrochemical etching of 3D micro probe array. The average depth etch rate and the average bias etch rate were measured as 1.50 plusmn 0.10 mum/min, and 0.77 plusmn 0.03 mum wide structure. The surface roughness of 11.34 nm has been measured. The demonstrated multi-step electrochemical etching process results in a simple, cost-effective, and timesaving fabrication of 3D metallic structures.