A method of making a polyimide (PI)-based material. In one embodiment, the method begins by dispersing a polyamic acid (PAA) oligomer and photo-initiator into a photo-reactive monomer to form a liquid resin. In contrast to the above-described prior art, the liquid resin is substantially devoid of any non-reactive solvents. Electromagnetic radiation is then applied (e.g., in a 3D printing operation) to solidify the liquid resin and to substantially form a interpenetrating polymer network (IPN) in which the PAA oligomer is entangled within the network formed by the photo-reactive monomer but remains substantially independent and un-crosslinked from the PAA oligomer. Thereafter, the PAA-based IPN is thermally cycled to form a polyimide-based IPN.

A method of printing a hydrogel-based device includes contacting a monomer, a crosslinker, a photoinitiator, and a precursor salt with a solvent to form an ink solution, printing the ink solution onto a substrate, exposing the ink solution to light, sufficient to form a hydrogel, and contacting the hydrogel with a reducing agent sufficient to precipitate nanoparticles from the precursor salt in the hydrogel.