Testing of Digital Microfluidic Biochips Using Improved Eulerization Techniques and the Chinese Postman Problem

Digital micro fluidic technology is now being extensively used for implementing a lab-on-a-chip. Micro fluidic biochips are often used for safety-critical applications, clinical diagnosis, and for genome analysis. Thus, devising effective and faster testing methodologies to warrant correct operations of these devices after manufacture and during bioassay operations, is very much needed. In this paper, we propose a technique to obtain the route plan of a test droplet for the purpose of structural testing of biochips. The technique is applicable to fully reconfigurable arrays and application specific biochips. We propose an improved eulerization technique to implement the test plan based on a graph model of the chip. The optimal eulerization can be abstracted in terms of the classical Chinese postman problem. The Euler tour can then be identified using a cycle decomposition method, which is easy to implement. This can also be used in phase-based test planning leading to significant savings in testing time. The method provides a unified approach towards unidirectional structural testing and can be easily adapted to design an improved droplet routing procedure for bidirectional functional testing of digital micro fluidic biochips.