Digital Signal Processing for Molecular Communication via Chemical-Reaction-Based Microfluidic Circuits

Chemical-reaction-based microfluidic circuits are expected to provide new opportunities to perform signal processing functions over the molecular domain. To realize this vision, in this article, we exploit and present the digital signal processing capabilities of chemical-reaction-based microfluidic circuits. To facilitate microfluidic circuit design, we describe a microfluidic circuit using a five-level architecture: molecular propagation, chemical transformation, microfluidic modules, microfluidic logic gates, and microfluidic circuits. We first identify the components at Levels 1 and 2, and present how their combinations can build the basic modules for Level 3. We then assemble basic modules to construct five types of logic gates for Level 4, including AND, NAND, OR, NOR, and XOR gates, which show advantages of microfluidic circuits in versatility and modularity. Finally, we discuss challenges and potential solutions for designing, building, and testing microfluidic circuits with complex signal processing functions in Level 5 based on the digital logic gates at Level 4.