Methods for the microfabrication of magnesium

The mechanical and electrochemical properties of magnesium are favorable for biomedical and energy storage applications. However, magnesium microfabrication has been limited to sub-micron-thick film technologies (i.e., sputtering or evaporation). This paper presents three magnesium microfabrication approaches for thicknesses greater than 10 μm: 1) laser-cutting and 2) chemical etching of 70-μm-thick commercial magnesium foil; and 3) through-mold electroplating of magnesium from non-aqueous solution. The fabrication technologies are compared on minimum feature size, morphology, uniformity, composition and electrical resistivity. Preliminary results confirmed that the 50-μm-thick electroplated material composition compared favorably with commercial magnesium foil. The measured electrical resistivities of commercial and electrodeposited magnesium were 5.3 μΩ·cm and 8.7 μΩ·cm, respectively. Thick magnesium microstructures can be fabricated through several means to serve a broad range of MEMS-based applications.