A critical review of additive material manufacturing through electrochemical deposition techniques

Additive manufacturing (AM) of micro metallic structures by traditional manufacturing techniques has several limitations. Electrochemical additive manufacturing (ECAM) is a cost-effective, environmentally friendly process and highly applicable for the fabrication of crack and void-free three-dimensional (3D) dense micro and nanosized metallic structures. Several microstructure nanomaterials have been fabricated through layer-by-layer electrochemical deposition using microdevice tips. Mask-less localized electrochemical deposition is a recently developed and non-traditional microstructure AM technology that originated from electrochemical deposition. It fabricates a 3D freestanding metallic microstructure layer by layer at an atomic level. In this review, the achievability of mask-based and mask-less electrochemical deposition as a non-thermal microstructure AM process is summarized. Additionally, the additive fabrication of different metallic microstructures metals such as the electrochemical deposition of nickel, copper, and the deposition of metal on anodic aluminum films are explained. The technical competencies and drawbacks of mask-less and mask-based electrochemical deposition are described. The influences of electrochemical deposition parameters including deposition time, current density, interelectrode gap, electrolyte pH, and temperature are broadly discussed. Moreover, this paper explains the current development and challenges of AM along with its materials and applications.