Stoma-inspired valve

Abstract

Soft robotics and microfluidics are interdisciplinary fields with shared methods for developing flexible and functional devices. However, manufacturing durable, efficient, and robust devices remains a challenge. One of the key hurdles is the limited number of valve designs available. Currently employed microvalves are either normally closed with negative control pressure or normally open with positive control pressure. However, there has not been a microvalve design reported which is normally closed and has positive control pressure, while it was present for an extended period in nature in the form of a plant stoma. Plant stoma is a robust normally closed valve with positive control pressure, with robustness arising from the fact that when the plant dries the valve closes. It was used as an inspiration source for the valve in this work, which is normally closed and opens at positive as well as negative control pressure, which are improvements over previously reported designs. The findings suggest the potential of this technology for applications ranging from artificial leaves to bioreactors. By considering nature as an inspiration source, a contribution was made towards more sustainable solutions.