We have demonstrated a new approach to the manufacture of self-folding hydrogel scaffolds by the use of readily available and fast throughput methods. The process shows effective pattern transfer by first embossing a sacrificial layer and using it as a soluble mould in the fabrication process. The use of a sacrificial layer of PAA imparts environmental sensitivity to the hydrogel film on only one surface. The subsequent swelling of the PAA inter-penetrating network (IPN) in elevated pH causes a swelling differential across the film, causing it to roll to accommodate the difference in surface area between the two surfaces. The surface functionalization and patterning stages are thus combined into one photolithographic operation. The net result is a method of producing environmentally triggered self-folding all hydrogel scaffolds by a, to the authors’ knowledge, novel use of sacrificial layer embossing. The patterned hydrogel films can be triggered consecutively allowing for successive rolling and unrolling depending on the aqueous pH. The choice of PEGDMA hydrogel provides a versatile platform for creating a variety of hydrogel scaffolds, and while being non-fouling and nontoxic it is permeable to proteins. Furthermore PEGDMA can be modified to produce biodegradable and cell adhesive hydrogels for a variety of biomedical applications.
