Digital light four-dimensional printing of programmable morphology and motion structures

A method of forming air-stable polymer structures, comprising:

• preparing a precursor solution;
• introducing the precursor solution into a cell;
• exposing the precursor solution in the cell with light to form a hydrogel structure from the precursor solution, the hydrogel structure comprising continuously varying, spatially controlled compositions and material properties;
• washing the hydrogel structure;
• storing the hydrogel structure in water;
• at least one of increasing the temperature of the water or exchanging the water with an ionic solution to increase the repulsion of water by the hydrogel structure and transition the hydrogel structure to a polymer structure;
• and
• removing the polymer structure from the solution.

A method of forming hydrogel structures programmed for motion between prescribed shapes, comprising:

• preparing a precursor solution;
• introducing the precursor solution into a cell;
• and
• exposing the precursor solution in the cell with light based on a growth function or growth pattern to form a hydrogel structure from the precursor solution, the hydrogel structure comprising continuously varying, spatially controlled compositions and material properties.