A method for fabricating a maskless dendritic silicon nanostructure array, in which a copper layer is deposited on a surface of a silicon substrate, and passivated to form an insulating passivation film; a first laser induction is performed using a first laser beam to remove the insulating passivation film from a designated region and form a primary needle-shaped protrusion structure; a second laser induction is performed on the primary needle-shaped protrusion structure using a second laser beam to form a secondary dome-shaped protrusion structure, thereby forming a dual-level needle-shaped seed layer; the dual-level needle-shaped seed layer is subjected to parameter-controlled electrodeposition to grow dendritic microstructures, so as to obtain a silicon wafer containing the maskless dendritic silicon nanostructure array. A silicon wafer with a silicon nanostructure array fabricated by such process is also provided.

A method for forming an Ag/AgCl coated electrode includes providing a polymeric electrode substrate made of Acrylonitrile Butadiene Styrene (ABS). A layer of silver (Ag) is deposited on the polymeric electrode substrate using physical vapor deposition (PVD) to form an Ag coated electrode. The layer of Ag is deposited to a first thickness by sputtering an Ag target onto the polymeric electrode substrate. The Ag coated electrode is then converted to a layer of silver/silver chloride (Ag/AgCl) by dipping it into a conversion solution. The resulting Ag/AgCl coated surface electrode provides improved performance and stability for various applications.