Disclosed herein is a method for forming a cable configured to convey neuron signals. The method can include forming two longitudinal halves of the cable and bonding the two longitudinal halves together. Each of the two longitudinal halves can be formed on a respective substrate and includes a plurality of groups of conductive traces each in a respective layer of the respective longitudinal half. Each respective group of the plurality of groups of conductive traces can formed by depositing a respective insulating layer, patterning the respective insulating layer, depositing a respective conductive layer over at least a portion of the patterned insulating layer, patterning the respective conductive layer into the respective group of conductive traces. Each respective layer of the respective longitudinal half can have a width smaller than a layer formed prior to the respective layer, and can have a thickness that is within a range of 2 microns and 10 microns.