A 3-D printed device comprising one or more interconnect structures, the interconnect structures comprising a plurality of conductive particles and one or more diblock or triblock copolymers; the diblock or triblock copolymers having an A-B, A-B-A, or A-B-C block-type structure in which the A-blocks and C-blocks are an aromatic-based polymer or an acrylate-based polymer and the B-blocks are an aliphatic-based polymer. These 3-D printed devices may be formed using a method that comprises providing a conductive ink composition; applying the conductive ink composition to a substrate in a 3-D solvent cast printing process to form one or more interconnect structures; and drying the one or more interconnect structures formed from the conductive ink composition. The dried interconnect structures exhibit a conductivity equal to or greater than 1×105 S/m without having to be subjected to any post-processing sintering treatment.