Micro-electrode-dot Array Based Biochips : Advantages of Using Different Shaped CMAs

Abstract

Recent emergence of micro-electrode-dot array (MEDA) based digital microfluidic biochips has facilitated major improvement in microfluidic operations for conventional lab-on-chip devices. MEDA based digital microfluidic biochips typically consist of a 2D planar array of cells of square sized microelectrodes. One of the most critical issues in the biochip layout design is the droplet transportation within the 2D layout. MEDA allows for dynamic routing with variable shaped and sized droplets. Microelectrode cells are dynamically group together to form configured microelectrode array (CMA) for variable shaped and sized droplets. This existing square shaped CMA is highly suitable for the droplets that needs exactly rectangular or square area but may not be as effective for rhombus or hexagonal shaped areas occupied by droplets. This is because the occupied additional area may be useful for other droplets to accommodate their corresponding minimum shortest path. In this paper, we present some MEDA layout design of 2D planar array of cells using triangle shaped microelectrodes by arranging them in a regular way. This allows for better convenience towards formation of different droplet shapes more efficiently, specifically for rhombus or hexagonal sized droplets. MEDA routing operations has been conducted on this newly proposed MEDA layout (using variable shaped electrodes) followed by analysis and comparison with existing MEDA layout design. Finally droplet transportation with standard bench marks are mapped in order to demonstrate how well the proposed designs can improve the performance of bioassay execution in MEDA based DMFB layout.