Self-adaptive control of smart hydrogels to water flow
智能凝胶对水流量自适应控制的仿生研究

Inspiration is from the plant root adjusting self-adaptively its structure and function according to the change of water content in soil; a macroporous polyvinyl formal hydrogel (PVFM) with water-content sensitivity was synthesized, and utilized as sensor and actuator to control automatically the drip-irrigation flow. PVFM hydrogel shows rather fast swelling/deswelling rate, and its mechanical behavior is sensitive to the change of water content, as a result the flow rate is modulated accordingly. This smart hydrogel can control self-adaptively water flow according to humidity of soil; the on-off cycle of flow control is less than 1 hour. It has the large potential applications in the aired regions for water-saving irrigation, humidity adjustment, desert control and so on.