Supplementary Figure S1. Preparation of composite gel sheets and their transformation in helical structures. a, Schematic of the photolithographic patterning of the hydrogel sheet. A sheet of PNIPAm gel (a primary gel or PG) is swollen with a monomer mixture, sandwiched between the two glass slides, and exposed through a The cell sheet successfully detached from the substrates upon cooling as the result of the thermo-responsiveness of PNIPAM. Colloidal PNIPAM hydrogel particles have found the potential applications in biomedical field because of their thermo-responsiveness.

A PNIPAm (PG) sheet was formed from an aqueous solution containing 14 wt% of NIPAm, 1 wt% of MBA and 1 wt% of V-50. The second aqueous polymer solution used for the preparation of PNIPAm/PNIPAm (BG) regions comprised 14 wt% of NIPAm, 1 wt% of MBA and 1 wt% of V-50. Synthesis of P(NIPAm-co-HEAM)/PNIPAm composite hydrogels PNIPAM hydrogel can be prepared by using precipitation polymerization. The NIPAM monomer (2.5 g), MBAAm cross-linker (0.025 g), and various amounts of sodium chloride should be dissolved in 45 g ... A PNIPAm (PG) sheet was formed from an aqueous solution containing 14 wt% of NIPAm, 1 wt% of MBA and 1 wt% of V-50. The second aqueous polymer solution used for the preparation of PNIPAm/PNIPAm (BG) regions comprised 14 wt% of NIPAm, 1 wt% of MBA and 1 wt% of V-50. Synthesis of P(NIPAm-co-HEAM)/PNIPAm composite hydrogels