Active liquid flow control through a polypyrrole-coated macroporous silicon membrane toward chemical stimulation applications

• Published in: Sensors and actuators. A. Physical. Vol. 318; p. 112512
• Main Authors: Rostami Azmand, Hojjat, Enemuo, Amarachukwu N., Seo, Sang-woo
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.02.2021; Elsevier BV
• Subjects: Active control; Chemicals; Control equipment; Electric potential; Electrodes; Flow control; Fluid dynamics; Liquid flow; Liquid flow control; Liquids; Low voltage actuation; Membranes; Organic liquids; Polypyrrole; Polypyrroles; Silicon; Tin dioxide; Valveless micropump; Voltage; Wetting; Valveless micropump; Liquid flow control; Low voltage actuation; Polypyrrole
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2020.112512

[Display omitted] •Demonstration of voltage-controlled liquid flow through a macroporous silicon membrane.•Three-dimensional fluidic channel array based on a macroporous silicon membrane.•Dynamic liquid flow control using polypyrrole-based electrochemical wetting change. In this paper, we demonstrate the voltage-controlled flow of organic liquid through a macroporous silicon structure. The demonstrated flow control structure consists of a silicon-based macropore membrane and flow control units formed on polypyrrole (PPy)-coated pores, which are actuated by its electrochemical wetting change. Conformal coating of a PPy layer along macropore silicon walls is achieved with the help of spray-deposited tin-oxide (SnO2) layer on the pores. The transport of organic liquid through the developed membrane is successfully controlled by low-voltage external bias on the PPy layer. Cyclic deliveries of organic liquid were demonstrated using the proposed concept. Considering the highly-ordered fluidic channel structure formed in silicon, which can have multiple separated electrodes, the proposed concept has the potential to achieve an actuated fluidic dispenser in an arrayed form.