Force-triggered rapid microstructure growth on hydrogel surface for on-demand functions

Living organisms share the ability to grow various microstructures on their surface to achieve functions. Here we present a force stamp method to grow microstructures on the surface of hydrogels based on a force-triggered polymerization mechanism of double-network hydrogels. This method allows fast spatial modulation of the morphology and chemistry of the hydrogel surface within seconds for on-demand functions. We demonstrate the oriented growth of cells and directional transportation of water droplets on the engineered hydrogel surfaces. This force-triggered method to chemically engineer the hydrogel surfaces provides a new tool in addition to the conventional methods using light or heat, and will promote the wide application of hydrogels in various fields.

Qifeng Mu, Kunpeng Cui, Zhi Jian Wang, Takahiro Matsuda, Wei Cui, Hinako Kato, Shotaro Namiki, Tomoko Yamazaki, Martin Frauenlob, Takayuki Nonoyama, Masumi Tsuda, Shinya Tanaka, Tasuku Nakajima, Jian Ping Gong