ph-sensitive sacrificial materials for the microfabrication of structures

A method of microfabrication of a composite structure having one or more well defined, reproducible two dimensional and/or three dimensional structures, features, or channels each having sizes between nanometers and centimeters comprising

• patterning or etching a sacrificial material formed from a first polymer to form a patterned sacrificial material structure, wherein the patterning or etching of the sacrificial material comprises a method selected from the group consisting of lithographic patterning, melt-spinning, wet-spinning, electrospinning, spin-coating, three dimensional printing, robotically controlled deposition, laser etching, plasma or chemical etching, stereolithography, selective laser sintering, ballistic particle manufacture, fusion deposition modeling, surface micromachining, bulk micromachining, and combinations thereof,
• embedding the patterned sacrificial material structure in a polymeric embedding material to form an embedded sacrificial material structure,
• wherein the patterned or etched first polymer is insoluble in a first solvent at a first pH and soluble in the first solvent upon a change from the first pH to a second different pH,
• contacting the embedded sacrificial material structure with a bath comprising the first solvent at the first pH;
• and
• changing the first pH of the first solvent to the second different pH, wherein the first polymer is solubilized in the first solvent at the second different pH,
• wherein the polymeric embedding material is not soluble in the first solvent at the second different pH, and
• removing the solubilized first polymer,
• wherein the removal of the first polymer forms the structures, features, or channels, having the pattern of the patterned sacrificial material structure, within the polymeric embedding material.