Damascene template for directed assembly and transfer of nanoelements

A method of assembling and transferring a two-dimensional patterned assembly of nanoelements onto a flexible polymer substrate, the method comprising the steps of:

• (a) providing a nanoelement transfer system and a liquid suspension of nanoelements, the nanoelement transfer system comprising
• (i) a nanoelement assembly device for creating a patterned assembly of nanoelements;
• (ii) a thermally regulated imprint device for applying pressure between the damascene template and a flexible polymer substrate at a selected temperature above ambient temperature for transfer of said patterned assembly of nanoelements onto said flexible polymer substrate;
• and
• (iii) a damascene template comprising
• a substantially planar substrate;
• a first insulating layer disposed on a surface of the substrate;
• an optional adhesion layer disposed on a surface of the first insulating layer opposite the substrate;
• a conductive metal layer disposed on a surface of the adhesion layer opposite the first insulating layer, or disposed on a surface of the first insulating layer opposite the substrate if the adhesion layer is absent;
• a second insulating layer disposed on a surface of the conductive metal layer opposite the adhesion layer, or opposite the first insulating layer if the adhesion layer is absent;
• and
• a hydrophobic coating selectively disposed on exposed surfaces of the second insulating layer opposite the conductive metal layer;
• wherein the conductive metal layer is continuous across at least one region of the substrate, and within said region the conductive metal layer has a two-dimensional microscale or nanoscale pattern of raised features that interrupt the second insulating layer;
• wherein the second insulating layer substantially fills the spaces between said raised features;
• and
• wherein exposed surfaces of the raised features and the exposed surfaces of the second insulating layer are essentially coplanar;
• (b) submerging the damascene template in the liquid suspension of nanoelements;
• (c) applying a voltage between the conductive metal layer of the submerged damascene template and a counter electrode in the liquid suspension, whereby nanoelements from the suspension are assembled onto the exposed surfaces of the raised features of the conductive metal layer of the damascene template and not onto the exposed surfaces of the second insulating layer of the damascene template, thereby forming a patterned assembly of nanoelements on a surface of the damascene template;
• (d) withdrawing the damascene template and attached patterned assembly of nanoelements from the liquid suspension while continuing to apply voltage between the conductive metal layer of a submerged portion of the damascene template and the counter electrode;
• (e) drying the withdrawn damascene template;
• and
• (f) contacting the patterned assembly of nanoelements attached to the damascene template with the flexible polymer substrate and applying pressure and heat using the thermally regulated imprint device, whereby the patterned assembly of nanoelements is transferred onto the flexible polymer substrate;
• wherein the contacting is performed at a temperature above the glass transition temperature of the flexible polymer substrate.