Abstract: Methods of forming an electrically conductive layer on a flexible substrate, such as a stretchable electrode, by aerosol jet printing on the flexible substrate while the substrate is strained. In general, a stretchable substrate is initially deformed so that a first surface thereof is under tension. While the substrate is in the strained state, an ink is aerosol jet printed onto the first surface. The ink includes carbon nanotubes, and advantageously other materials such as reduced graphene oxide. Further, while the substrate is still in the strained state, the ink is cured after its application to the substrate. Thereafter, the strain is decreased so that the stretchable substrate contracts, self-organizing into a configuration wherein the substrate's first surface, with the cured ink thereon, has a wrinkled profile. The flexible substrate can then be mechanically expanded and contracted, advantageously repeatedly, with the ink layer maintaining electrical conductivity.