Biomimetic undulated microwrinkles construction by orienting microparticles in responsive hydrogel sheets via dielectrophoresis

The construction of a biomimetic and seamless hydrogel scaffold featuring 3D undulated microwrinkles by orienting microparticles within hydrogel sheets via dielectrophoretic (DEP) is first reported. We demonstrated the formation of (1) periodic microwrinkles and (2) gradient undulated wrinkles on hydrogel sheets can be achieved by controlling the length of microparticle chains in the hydrogel. Moreover, the aligned microparticles not only can cause the 3D wrinkling geometries of hydrogel sheets, but they can also be used as carriers to load bioactive molecules, such as morphogens, cytokines, and growth factors, for achieving spatial and temporal release payload in hydrogel scaffolds for further biomedical applications. This novel approach to create 3D undulated microwrinkles with versatile wavelengths, amplitudes, and curvatures is suitable for constructing biomimetic scaffolds and become an alternative technology to additive manufacturing and 3D printing to construct more complicated and heterogeneous 3D scaffold.